Author Topic: OWON XDM1041 the unknown multimeter...  (Read 75502 times)

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Offline ScrachiTopic starter

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OWON XDM1041 the unknown multimeter...
« on: February 25, 2021, 08:53:04 am »
Hi,
I've found on ebay the bench multimeter OWON XDM1041 : https://www.ebay.fr/itm/OWON-XDM1041-3-7in-LCD-Mini-Desktop-Digital-Multimeter-True-RMS-Tester-Meter-New/164717198621?hash=item2659e8fd1d:g:ARwAAOSwLYRgM4M~

But I don't find any information about it outside of the ebay product description, I've also checked on the Owon website but no info about it. I've sent an email to the Owon contact to try to get info, no reply yet.

Comparing the specs, they are pretty close to the Owon xdm2041.

Someone know this product ?

Thanks.
 
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Offline paf

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Offline Fungus

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Re: OWON XDM1041 the unknown multimeter...
« Reply #2 on: February 25, 2021, 10:00:39 am »
Certainly a nice form factor...


Only two or three hits on google, maybe it's a very new model.

« Last Edit: February 25, 2021, 10:02:39 am by Fungus »
 

Offline ScrachiTopic starter

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Re: OWON XDM1041 the unknown multimeter...
« Reply #3 on: February 25, 2021, 12:31:37 pm »
Thanks for the link.

Yes it seems to be a new model, I like the small size of the box instead of the big box of the usual bench multimeters. I will wait if I can find more info/review of it but I think it can fit pretty well in my small lab...  :)
 

Offline ScrachiTopic starter

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Re: OWON XDM1041 the unknown multimeter...
« Reply #4 on: February 27, 2021, 09:27:09 am »
Hi,
I've just got the confirmation from Owon it is a new model:
Owon email : "it is a new one, you will see on our website later."
 

Offline maxwell3e10

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Re: OWON XDM1041 the unknown multimeter...
« Reply #5 on: March 01, 2021, 05:48:49 am »
It's a nice form factor and inexpensive. Unfortunately, just like for XDM2041, they probably will disable all fancy functions, like math statistics and trend chart. So its no better than a hand-held, although there is value in having the multimeter always on. A better choice would be to keep analysis functions to take advantage of the nice LCD display. That would set it apart from other simple bench meters.
 

Offline Mp3

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Re: OWON XDM1041 the unknown multimeter...
« Reply #6 on: March 01, 2021, 07:49:53 am »
I also noticed this recently and was curious if it had anything to offer over one of the East Testers, which gets constant use in my lab and I love.
High school graduate
 

Offline ScrachiTopic starter

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Re: OWON XDM1041 the unknown multimeter...
« Reply #7 on: March 01, 2021, 02:06:23 pm »
Yes for the moment I don't find any specific info about the features. I'm waiting for the "official" Owon presentation to get the user manual and check all features.
 

Offline EEVblog

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Re: OWON XDM1041 the unknown multimeter...
« Reply #8 on: March 10, 2021, 12:37:23 pm »
Just stumbled across this myself on ebay.
I kinda like the look of it!
Shame it's not battery powered.


« Last Edit: March 10, 2021, 12:40:02 pm by EEVblog »
 

Offline coromonadalix

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Re: OWON XDM1041 the unknown multimeter...
« Reply #9 on: March 10, 2021, 03:27:39 pm »
same footprint as a scope it seems ??

Damn   gonna click to buy one  arrr  will i or not  loll

Around 200$ cad  shipping included, seems good to me
« Last Edit: March 10, 2021, 03:37:36 pm by coromonadalix »
 

Offline ScrachiTopic starter

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Re: OWON XDM1041 the unknown multimeter...
« Reply #10 on: March 10, 2021, 04:24:49 pm »
I regularly check if I can find the user manual or an official presentation on the Owon site but nothing yet... It will be cool if they can have a measure logging function.

Just bad, they do not have 4 wire resistor measurement...

Who will click on "buy" first?  ;D

 

Offline tunk

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Re: OWON XDM1041 the unknown multimeter...
« Reply #11 on: March 10, 2021, 04:31:04 pm »
In the photo above, professionals at work? - do I see a DT830B multimeter?  :-DD
 

Offline msquared

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Re: OWON XDM1041 the unknown multimeter...
« Reply #12 on: March 10, 2021, 06:15:26 pm »
Punched the buy button last week.  :)

I think the form factor will be perfect for probing and glancing up without having to move my eyes to far away. I known it can be done with a bench meter or hand held but bench meters are big and deep and handhelds are usually at a funky angle when sitting on the tilting bale.

And like that it has a real IEC cord for power and I don't have to deal with batteries or keeping track of the right plug pack. (sorry Dave)

I wouldn't expect it to have great protection or accuracy but it should be good for basic troubleshooting and probing around an Arduino.

Also in the past I've gotten really good support from Owon for one of their USB scopes so I have some confidence that if there are any issues they'll standby their products.

All yet to be seen. If I get it first I'll post pictures of the innards and let the real experts post their analysis and opinions.
 
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Offline coromonadalix

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Re: OWON XDM1041 the unknown multimeter...
« Reply #13 on: March 10, 2021, 10:48:15 pm »
Tons of sellers with timed offers ...  witch one i should use or buy   damn :(

The cheapest price is around 125$ usd with a 49 cent shipping  loll  and the others around 150$ usd with 17$ usd  shipping ???

And the surprises are in the handling time,  most says 10 days after the payment is received and some goes up to 21 days ???
« Last Edit: March 10, 2021, 10:52:47 pm by coromonadalix »
 

Offline EEVblog

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Re: OWON XDM1041 the unknown multimeter...
« Reply #14 on: March 12, 2021, 12:07:37 pm »
I wouldn't expect it to have great protection

As with almost all benchtops regardless of price, it's only CAT II rated. But good enough for basic mains bench work.
 

Offline wraper

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Re: OWON XDM1041 the unknown multimeter...
« Reply #15 on: March 12, 2021, 12:13:52 pm »
Thanks for the link.

Yes it seems to be a new model, I like the small size of the box instead of the big box of the usual bench multimeters.
There is nothing nice about it if you intend to use it as a bench meter. It will be pushed back when you try pressing any button, so you will need to hold it with another hand when pressing buttons.
 

Offline Fungus

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Re: OWON XDM1041 the unknown multimeter...
« Reply #16 on: March 12, 2021, 01:02:01 pm »
There is nothing nice about it if you intend to use it as a bench meter. It will be pushed back when you try pressing any button, so you will need to hold it with another hand when pressing buttons.

Put your hand on top and press with the thumb.

Pressing with index finger will be uncomfortable anyway at that height/angle.
 

Offline coromonadalix

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Re: OWON XDM1041 the unknown multimeter...
« Reply #17 on: March 12, 2021, 03:18:40 pm »
add concrete in it  loll   it wont move  :-DD
 

Offline robert.rozee

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Re: OWON XDM1041 the unknown multimeter...
« Reply #18 on: March 13, 2021, 04:13:21 am »
one could possibly 3d-print an alternative back housing, with extra length containing batteries and/or a lead weight, space for storing leads, carry handle, etc.

i look forward to seeing a teardown   :-+


cheers,
rob   :-)
 

Online DaneLaw

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Re: OWON XDM1041 the unknown multimeter...
« Reply #19 on: March 14, 2021, 01:37:42 am »
Many ways to put it somewhat stable on the desk.
even a crude pair of silicone feet will prevent it from sliding around to much, otherwise you have this tape'ish rubber-like materiel, you can put underneath that almost grap the surface and if it gets dirty you can take it off and wash it and its good as new.
also recall its that materiel they are now fitting on products like Insta360 Go2 wall-mounts for the camera and no actual adhesive, just very grippy rubberlike materiel. you can put behind a given product.
Same with RC and batteries on quads so the LIPO aint sliding.
It seems they have come a long way since those silicone pads, you could use on your deck in the car for phones and coins..
 

Offline Microcheap

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Re: OWON XDM1041 the unknown multimeter...
« Reply #20 on: March 16, 2021, 08:39:29 am »
I've contacted Owon asking more details about this new meter and they sent me a spec sheet with some more information, including a picture of the inside (see pdf attached. I had split the file as it was a bit over the forum's 4MB limit).

It looks interesting, at least more useful than the AN888S but BW is only 1kHz and the dual display only shows VAC + Hz. Apparently, they are planning to update the serial communication to USB soon.
 
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Offline coromonadalix

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Re: OWON XDM1041 the unknown multimeter...
« Reply #21 on: March 16, 2021, 09:34:16 am »
1khz ac bandwidth   seriously ??   Any serious company should have a 100khz on any modern meter
 

Offline ScrachiTopic starter

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Re: OWON XDM1041 the unknown multimeter...
« Reply #22 on: March 16, 2021, 10:10:51 am »
Thanks for the PDF very useful, so the functions are very similar with the OWON XDM2041
 

Offline robert.rozee

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Re: OWON XDM1041 the unknown multimeter...
« Reply #23 on: March 16, 2021, 10:30:55 am »
1khz ac bandwidth   seriously ??   Any serious company should have a 100khz on any modern meter

well, it can calculate TRMS on anything between 20Hz and 1kHz, but it can measure frequencies up to 60MHz according to the above datasheet. bear in mind that TRMS, if done digitally, requires a fair bit of oversampling to work.

also of note, temperature can be measured with either k-type thermocouple or a resistive PT100 sensor.

from the inside views, it looks like there is a 5-wire connector off the multimeter PCB running to the AC PSU and serial PCBs. an educated guess is that this carries a single-ended supply (2-wires) and opto-isolated serial (3-wires). if this is the case, modification for battery powered may well be on the cards    :-+


cheers,
rob   :-)
« Last Edit: March 16, 2021, 10:34:01 am by robert.rozee »
 

Online indman

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Re: OWON XDM1041 the unknown multimeter...
« Reply #24 on: March 16, 2021, 10:44:09 am »
It looks interesting, at least more useful than the AN888S but BW is only 1kHz and the dual display only shows VAC + Hz.
The 1kHz BW deprives this model of all advantages and equates it to the AN888S and similar low-cost devices. ;)
 

Offline paf

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Re: OWON XDM1041 the unknown multimeter...
« Reply #25 on: March 16, 2021, 11:40:38 am »
The good things about this multimeter are the looks and the small size,
But, an East Tester ET3240 can be had for 130 Euros in EU  (Aliexpress but delivery from CZ!) and has 4 wire resistance measurements...

Review:
https://lygte-info.dk/review/DMMEastTester%20ET3240%20UK.html

What do you think?



 

Offline Fungus

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Re: OWON XDM1041 the unknown multimeter...
« Reply #26 on: March 16, 2021, 12:01:24 pm »
The good things about this multimeter are the looks and the small size,
But, an East Tester ET3240 can be had...

What do you think?

I think the East Tester ET3240 looks far too big for my bench and is ugly. ;-)
« Last Edit: March 16, 2021, 12:09:54 pm by Fungus »
 
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Offline Fungus

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Re: OWON XDM1041 the unknown multimeter...
« Reply #27 on: March 16, 2021, 12:08:33 pm »
1khz ac bandwidth   seriously ??   Any serious company should have a 100khz on any modern meter

Don't you have an oscilloscope for that?

High frequency multimeters were for back when oscilloscopes were really expensive and didn't do on-screen calculations. 1kHz will cover just about all AC measurements made with a multimeter these days.
« Last Edit: March 16, 2021, 12:10:36 pm by Fungus »
 

Online indman

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Re: OWON XDM1041 the unknown multimeter...
« Reply #28 on: March 16, 2021, 12:30:31 pm »
1khz ac bandwidth   seriously ??   Any serious company should have a 100khz on any modern meter
Don't you have an oscilloscope for that?
1kHz will cover just about all AC measurements made with a multimeter these days.
And why should I take out and turn on the oscilloscope if I can easy measure AC with a multimeter which has a bw of 10-100kHz? ;)
 

Offline Kleinstein

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Re: OWON XDM1041 the unknown multimeter...
« Reply #29 on: March 16, 2021, 12:55:45 pm »
1 kHz BW limit for the TRMS mode is a bit low. However it depends on how sharp the limit is. A lower BW can also have the positive side of seeing less noise.
For digital RMS one does not necessary need a lot of oversampling. Just some pseudo random sampling timing is enough and could even work with undersampling (e.g. 1 MHz BW with 100 kHz sampling).
The BW limit may as well be due to the analog input part.

The BW specs for the analog RMS chips are also a bit tricky: at lower amplitude the BW can go down and this can cause linearity errors. At some 5 or 10% of the fullscale (this may be a range one may have to chose for some signals) the BW may no longer be that large.


It looks funny to have a maximum speed of some 65 readings per second - that is just a little faster than 1 PLC. So one would get only slightly higher speed at the price of no longer mains hum supression and possible aliasing that can cause confusion. I would normally consider the range of 51/61 SPS to some 250 SPS as relatively useless, as it is effected by mains hum, but can not really resolve it. If the meter does RMS the digital way, which is a reasonable decision, they should be able to do faster readings (e.g. 2 kSPS) too. Maybe they should switch from slow RS232 to USB.
 

Offline rsjsouza

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Re: OWON XDM1041 the unknown multimeter...
« Reply #30 on: March 16, 2021, 01:17:33 pm »
It looks interesting, at least more useful than the AN888S but BW is only 1kHz and the dual display only shows VAC + Hz.
The 1kHz BW deprives this model of all advantages and equates it to the AN888S and similar low-cost devices. ;)
I agree with you; the form factor is pretty interesting, but its price takes it to the level of very capable handhelds. It is a pass for me.
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Oh, the "whys" of the datasheets... The information is there not to be an axiomatic truth, but instead each speck of data must be slowly inhaled while carefully performing a deep search inside oneself to find the true metaphysical sense...
 

Offline Fungus

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Re: OWON XDM1041 the unknown multimeter...
« Reply #31 on: March 16, 2021, 02:05:29 pm »
It is a pass for me.

I'd give it a pass, too. Definitely looks better than the Aneng bluetooth speaker thing. :-+

The probes look horrible but you can get awesome probes for $4 on Aliexpress, so... no biggie.  :P
« Last Edit: March 16, 2021, 02:13:17 pm by Fungus »
 

Offline msquared

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Re: OWON XDM1041 the unknown multimeter...
« Reply #32 on: March 16, 2021, 09:59:07 pm »
Got the dreaded ebay message today for my XDM1041 order:

"I am writing here with all my sincereness to say sorry to you .
I was just informed that your package are sending back due to the customs issue .Ebay suggest us to refund you all to protect your Consumer Rights in this condition ."

Looks like I need to find a new seller. This one had over 172k in their feedback score, thought I was in good hands.  :palm:
 

Offline rsjsouza

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Re: OWON XDM1041 the unknown multimeter...
« Reply #33 on: March 16, 2021, 11:37:12 pm »
msquared, this is better than what the Aneng Official Store did to me: they said that shipped the order and it was in the courier's hands. Three months later they tried to stall my dispute by moving the processing dates and on its final days they said the package was located and returned to them due to a "customs issue". Obviously they offered to resend the package to avoid the bad review and the cancellation.
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Oh, the "whys" of the datasheets... The information is there not to be an axiomatic truth, but instead each speck of data must be slowly inhaled while carefully performing a deep search inside oneself to find the true metaphysical sense...
 

Offline coromonadalix

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Re: OWON XDM1041 the unknown multimeter...
« Reply #34 on: March 17, 2021, 05:53:13 am »
I cancelled a purchase

Did not liked the seller bad purchases reviews / comments in the last month(s),  tried the sellers with the most sales amounts ....   with timed sales countdown and low quantities, that's a don't buy signal for me
 

Offline m.p.h

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Re: OWON XDM1041 the unknown multimeter...
« Reply #35 on: April 09, 2021, 11:22:32 am »
Hi All!

Does anyone have a user manual for the XDM1041?

Looked almost everywhere, but even the DEU dealer "Messgeräte Chemnitz" has nothing available  |O

Have a great day!

Michael
 

Offline msquared

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Re: OWON XDM1041 the unknown multimeter...
« Reply #36 on: April 09, 2021, 05:25:31 pm »
I got mine yesterday. Here's a couple of quick observations and results from my initial playing around, I should have more time this weekend.

If anyone wants any specifics let me know.

First the bad:
  • No real manual included, just a quick start guide.
  • Display is slow to update when changing functions or modes (you can watch it clear screen like an old terminal)
  • Not instant on, takes about 5 seconds to boot (Also you have to hold the power button for 2-3 seconds to power on)
  • Would have been nice to have some flip out front feet to change the angle
  • Auto range is slow, it takes a few seconds to "lock on". I noticed this on all functions

Now the good:
  • Small with big display, fits on the bench nicely
  • Doesn't really tip over when pressing buttons, top buttons tend to make it tip a bit but buttons are fairly soft with a nice tactile feel
  • Continuity is fast and configurable from 1-1k but not as fast below the 50 \$\Omega\$ default, buzzer is loud but not screaming
  • AC voltage drops off sharply at 4K not the 1K in the specs at least @ 5V RMS
  • Meter is accurate 5V using my DMMCheck comparing to readings on Keithly 2001 (Honestly to be expected, it's not that difficult to manufacture a decent 55k count meter today)
  • As above for current, resistance, and capacitors
 

Offline thoeffer

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Re: OWON XDM1041 the unknown multimeter...
« Reply #37 on: April 13, 2021, 03:46:53 pm »
I picked up the XDM2041 as I was looking for something that would sit on top of the Fluke 8840a.
I know WHY did I get it if I had the FLUKE? CAPACITANCE Checker & Frequency counter. Thats it.

It is a bit slow changing modes & autoranging. But it works well. I would have to spend a LOT more
to get a Meter with a  Frequency Counter that goes as high or waste more bench space getting a
dedicated Counter. I'm just a hobbyist anyways not a REAL EE.

I'll post pics later tonight.

Ty Hoeffer
Palmyra, VA
 
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Offline theHWcave

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Re: OWON XDM1041 the unknown multimeter...
« Reply #39 on: April 22, 2021, 09:55:01 pm »
thanks msquared,  I like the form factor because it would fit nicely on the shelf above my work table but I am slightly worried that the screen will burn in if left on for hours on end. Does it have a screen saver or something ?
Any experience (good or bad) with data logging and the PC interface?
 

Offline msquared

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Re: OWON XDM1041 the unknown multimeter...
« Reply #40 on: April 23, 2021, 04:29:52 am »
I couldn't find any screensaver but it is possible to turn the back light up and down in 25% increments making the screen pretty dark but I don't know if that will really make any difference in screen life or burn-in.

As far as the data logging goes... I tried the XDM2041 software but that was a no go. I was able to connect to the serial port (which is fully configurable from the UI with all the typical serial settings) and using the XMD2041 programming guide as a reference got it talking through putty in about a minute (there's no echo so you're typing blind). The command set is pretty easy, just basic SCPI so nothing to difficult. I don't think it's going to be much of a task to get it logging.

The other slight annoyance I've had is it doesn't remember the previous settings, it always defaults to "slow" mode but for quick troubleshooting or a couple of measurements "fast" mode works much better for auto ranging.

Overall still pretty happy with the little bench meter. I used to keep a Fluke 289 on the bench but know it's sitting on a shelf and the little meter has taken it's place.
 

Offline Fungus

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Re: OWON XDM1041 the unknown multimeter...
« Reply #41 on: April 23, 2021, 07:38:40 am »
thanks msquared,  I like the form factor because it would fit nicely on the shelf above my work table but I am slightly worried that the screen will burn in if left on for hours on end. Does it have a screen saver or something ?

I don't think it will have an OLED screen at that price.  :popcorn:

 
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Offline theHWcave

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Re: OWON XDM1041 the unknown multimeter...
« Reply #42 on: April 24, 2021, 09:45:35 am »
many thanks for the update msquared, I am probably going to get one ... (not that I really need yet another multi-meter)  :-DMM
 

Offline coromonadalix

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Re: OWON XDM1041 the unknown multimeter...
« Reply #43 on: April 24, 2021, 10:51:36 am »
Can we see the inside without breaking the warranty ??
\
Duh sorry  |O
« Last Edit: April 24, 2021, 05:52:23 pm by coromonadalix »
 

Offline Oilngas

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Re: OWON XDM1041 the unknown multimeter...
« Reply #44 on: April 24, 2021, 04:45:21 pm »
"Can we see the inside without breaking the warranty ??"

There is a picture of the inside in the first pdf attached in reply #20.
Lots and lots of VTVM's and Triplett analog multimeters
 

Offline martinr33

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Re: OWON XDM1041 the unknown multimeter...
« Reply #45 on: May 01, 2021, 02:28:02 am »
 
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Offline coromonadalix

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Re: OWON XDM1041 the unknown multimeter...
« Reply #46 on: May 01, 2021, 07:34:35 am »
hy3131 based dmm ic

same as the eevblog 121gw  ....
 

Offline SpecialK

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Re: OWON XDM1041 the unknown multimeter...
« Reply #47 on: May 02, 2021, 03:29:56 am »
Tons of sellers with timed offers ...  witch one i should use or buy   damn :(

The cheapest price is around 125$ usd with a 49 cent shipping  loll  and the others around 150$ usd with 17$ usd  shipping ???

And the surprises are in the handling time,  most says 10 days after the payment is received and some goes up to 21 days ???

https://www.amazon.ca/dp/B08VNNYMTB/?coliid=I1CDLRHLC3DHDN&colid=3GVSYACE2F0LE&psc=1&ref_=lv_ov_lig_dp_it

$164 CDN with a $15 coupon.  I'm pretty tempted.  I have an XDM3051,which other than having a fan that's a bit on the loud side, is pretty good,
 This looks like the same user interface.
 
 

Offline pallav.aggarwal@gmail.com

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Re: OWON XDM1041 the unknown multimeter...
« Reply #48 on: May 02, 2021, 07:07:05 pm »
I have purchased this multimeter recently and quite happy with the performance so far. The main purpose was to use it in my test jig.

I have also created a small video: https://youtu.be/rBGuiqlnOJM

2nd video showing how to interface with SCPI commands: https://pallavaggarwal.in/owon-xdm1041-programmable-multimeter/

Hope this will be useful for some people.
« Last Edit: May 04, 2021, 07:41:46 pm by pallav.aggarwal@gmail.com »
Best Regards
Pallav Aggarwal
https://pallavaggarwal.in/my-story/
 
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Offline Oilngas

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Re: OWON XDM1041 the unknown multimeter...
« Reply #49 on: May 02, 2021, 08:02:51 pm »
Tons of sellers with timed offers ...  witch one i should use or buy   damn :(

The cheapest price is around 125$ usd with a 49 cent shipping  loll  and the others around 150$ usd with 17$ usd  shipping ???

And the surprises are in the handling time,  most says 10 days after the payment is received and some goes up to 21 days ???

https://www.amazon.ca/dp/B08VNNYMTB/?coliid=I1CDLRHLC3DHDN&colid=3GVSYACE2F0LE&psc=1&ref_=lv_ov_lig_dp_it

$164 CDN with a $15 coupon.  I'm pretty tempted.  I have an XDM3051,which other than having a fan that's a bit on the loud side, is pretty good,
 This looks like the same user interface.

As noted in my earlier post, "Owon" does not show up in the Amazon pictures or the description, just "XDM1041".  Not sure if this is significant but it seems a little sketchy to me. :-//
Lots and lots of VTVM's and Triplett analog multimeters
 

Offline rsjsouza

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Re: OWON XDM1041 the unknown multimeter...
« Reply #50 on: May 02, 2021, 10:43:08 pm »
This is not uncommon. These DMMs usually have several OEMs and Amazon sellers sometimes test the waters with unknown brand names - I got a Sinerky UT136C (Uni-T UT136C), a no-name DM139C (Uni-T UT139C) and a single batch production Surpeer AV4 (HY-19 IIRC) - all at a significant price reduction at the time.
Vbe - vídeo blog eletrônico http://videos.vbeletronico.com

Oh, the "whys" of the datasheets... The information is there not to be an axiomatic truth, but instead each speck of data must be slowly inhaled while carefully performing a deep search inside oneself to find the true metaphysical sense...
 

Offline Kleinstein

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Re: OWON XDM1041 the unknown multimeter...
« Reply #51 on: May 03, 2021, 07:25:31 am »
That meter may show up under different names in the future. The OWON brand is nothing to be really proud off like a Fluke, HP or similar name.
It looks like the meter does not show the brand name and so the seller did not add it, which is OK. If the seller would add the brand one could also get suspicious.

The internals looks reasonable, with plenty of creapage distance as it should be. One point I don't like that much is that they use a SMPS and not a classic mains transformer. This may lead to extra common mode injected signal. The max. power at 15 W looks quite high. Even with just 15 VA and a relatively poor power factor it look high to me.

It is nice that they have the RS232 part separate (looks like a max232 or similar on the small board). So there may be a easy way to change to the more logical direct USB.
Chances are the RS232 version is some 20 cents cheaper.
 

Offline Doctorandus_P

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Re: OWON XDM1041 the unknown multimeter...
« Reply #52 on: May 09, 2021, 05:13:43 pm »
First:
Tnx for posting pictures of the internals.

I found this thread after first seeing it announced (from 2021-05-13) in a local shop:
 https://www.eleshop.nl/owon-xdm1041-multimeter.html

and then I started looking for more info, and found this thread.

I have been looking for a decent Benchtop DMM (Big display, fits on shelf, PC connectivity Push buttons instead of rotary selector etc.) for quite some time.
I do not have room for a 30cm deep meter though, and that is the reason I did not buy a Siglent 3045. The Siglent is also too slow for me in autoranging and connectivity test.

Somewhat slow autoranging is accepable for a low power battery operated instrument, but it's inexcusable for a benchtop instrument.

After I found out this uses the HY3131 I've been looking into that chipset a bit and it's quite popular for handheld meters:
EEVblog 121GW. (EUR200 meter)
Keysight 1280. ( EUR 600 meter)
HoldPeak HP770D ( EUR 50 meter)
Digilent DMM shield (EUR90) (No display, but Isolated interface)

Eleshop announces it (localy in EU) for EUR 130 and this is definitely in my price range, and I like the form factor, push buttons and big TFT.
I'm curious how far this HY3131 chipset can be pushed. Ideally it would be programmed to do some auto-sensing, and switches to a quick mode for auto-ranging, and to an accurate mode for more digits.

There is a EEVblog thread about reverse-engineering and alternate firmware for a Fnirsi scope. I do not understand that effort. After looking into it the frontend of the fnirsi scope is simply not good enough to make something decent out of it (Quite a shame, it could be a very decent thing for a BOM of EUR10 more...)

This XDM1041 looks extremely hackable though. The HY3131 complete with all measuring stuff and isolated interface is on a separate PCB from the "brains" part.
The whole microcontroller board can be easily replaced by your favourite, and then you can write any software you want for it, and if you stay with STM32 then once firmware development has surpassed what Owon does you can flash it into the on-board GD32F303.

I do not understand why Dave is complaining about why a benchtop DMM does not run on batteries. It seems a bit silly to me.
But if you must...
I find the Glue on SMPS module hilarious. It is also very easy to replace it with any power module you would like, including a battery pack, and I guess there is plenty of room left in the compact housing to add some decent batteries.

Another hackable upgrade for this scope would be to add a uSD or dataflash chip for datalogging. Should not be too difficult.

I do not give much for CAT ratings, I thing they're much overrated (for home or benchtop use). I'd rather have 50ct fuses then EUR10 fuses!
This XDM1041 has some decent sized fuses, widely spaced components and even some well placed isolation slots.

Overall, I'm not sure which path to follow.
Almost all decent benchtop meters are simply too big for me. I do not like the rotary buttons of the (cheaper) benchtop UNI-T meters, nor the simplistic LCD of the more expensive UNI-T, and others with fluorescent displays are also not for this generation anymore. Simply can't compete with a TFT.

I am looking forward to an in depth review of this meter. Especially auto ranging speed and the speed (and quality) of the continuity tester.
Another point that is a real deal breaker for me is a peep function that warns if the probe is in a current banana bus, while voltage measurement is selected. That is just a too simple mistake to make, and it either destroys your meter, or it destroys both a EUR10 fuse and your probe tips. Just happened too many times for me.
 

Offline SpecialK

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Re: OWON XDM1041 the unknown multimeter...
« Reply #53 on: May 09, 2021, 06:29:45 pm »
A couple days ago the Amazon link I posted went down to $148 CAD minus a $15 coupon.  I was very tempted even though I don't need it.

Now it's $218 minus $15.  To be fair, the Siglent 4.5 digit is like $500 and the 5.5 digit over $600.  There's very little to choose from in bench DMMs at hobbyist prices.  I think this should be a popular meter.
 

Offline coromonadalix

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Re: OWON XDM1041 the unknown multimeter...
« Reply #54 on: May 09, 2021, 07:01:50 pm »
Seeing other meters based on the hy3131  surely getting faster auto ranging should / could be possible ?

For a battery pack,  you have the battery bank for cell phones who could do a very good job, i have one based on 18650 cells  that could be called a 25000 ma  model loll

I think it could snug in there or behind it ??


Yeah the smps psu  was fun to see in there
 

Offline martinr33

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Re: OWON XDM1041 the unknown multimeter...
« Reply #55 on: May 10, 2021, 04:54:35 am »
The original photos of the innards (on the brochure) show a power supply integrated with the PCB.

So we are looking at some kind of fix here. Esecially with the corner rounding and cutoff on the board - that's a reworked board from another design.


https://photos.app.goo.gl/oj4yj544yRkzSndb6
 

Offline rsjsouza

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Re: OWON XDM1041 the unknown multimeter...
« Reply #56 on: May 10, 2021, 09:28:07 am »
Wow, that's an ugly fix! It seems rushed and desperate to put product out.
Vbe - vídeo blog eletrônico http://videos.vbeletronico.com

Oh, the "whys" of the datasheets... The information is there not to be an axiomatic truth, but instead each speck of data must be slowly inhaled while carefully performing a deep search inside oneself to find the true metaphysical sense...
 

Offline theHWcave

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Re: OWON XDM1041 the unknown multimeter...
« Reply #57 on: May 17, 2021, 11:00:22 pm »
I just got mine thru Ebay, straight from China to the UK, took about 2 weeks although the seller said 4 weeks.
Interestingly, my power supply is exactly like in the brochure, no ugly fix
but they cheated on the fuses, instead of 2 decent 30 mm long high rupture ceramic as in the brochure, I got cheap 20mm long ones rated for 250V only, at least the 10A is ceramic.

Other than the slowness already mentioned, the meter is quite ok for what it is. After a weekend of intense testing my summary is:
the negatives:
  • Capacitance above 500uF, auto range is not always working and one has to do manual ranging... capacitance is definitely the weakest mode anyway, the lowest range is just 50nF and 500pF or less shows only zero
  • Ranging in volt mode is weird: it can auto range from the millivolt up to volts but not down from volts to millivolts. Same with manual ranging. To go from volts to millivolts or back you can't use the range up down, instead you have to select between volt and mV mode. You can get used to i, but interestingly this is just a problem of the user interface. The behaviour over SCPI is much more sensible, you can just go up and down using the RANGE command or use the CONF command without any issue.
  • Rel mode is actually a maths function which means you can't have rel active and do averaging or dB/dBm at the same time since only one function can be active at a time 
  • No smart data hold which would have been easy in software..., just a silly run/stop button which is like a dumb hold 

on the plus side:
  • I really like the temperature mode. Very comprehensive and can do PT100 or K-type
  • The SCPI interface (RS-232) has its quirks, syntax wise, but once figured out, it works well and can deliver more decimals than shown on the display. Using that the accuracy is pretty good.
  • The display is easy on the eyes, especially if those eyes are not as young anymore...
  • It fits exactly under the first tier of the shelf at the back of my bench. That space is very shallow and very low, which is why I got this meter for it. It does not take any extra space on the work area, its mains powered and can be on the whole day, and its display is exactly at the right angle .

And if you have not guessed it... the meter is always on as long as it's plugged into mains.The power switch on the front is only a soft-switch, but I measured the "standby" current to be only about 1mA at 230V, so its not too much of an issue.
 
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Offline coromonadalix

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Re: OWON XDM1041 the unknown multimeter...
« Reply #58 on: May 18, 2021, 12:02:26 am »
would be nice if Owon could read this thread and improve the meter in a fw update ??
 

Offline msquared

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Re: OWON XDM1041 the unknown multimeter...
« Reply #59 on: June 02, 2021, 08:25:31 pm »
It's finally official.

https://www.owon.com.hk/products_owon_4_1%7C2_digits_xdm1041_bench-type_digital_multimeter

Also looks like there's already a newer version with a USB data port instead of RS232.

So much for being an early adopter. Maybe time for a little internal USB mod...


 

Offline theHWcave

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Re: OWON XDM1041 the unknown multimeter...
« Reply #60 on: June 02, 2021, 11:00:22 pm »
I have this meter and I would strongly advise caution in trusting anything that's written on that Owon Hongkong page. Notice how they dither between USB or RS-232? They avoid making a clear statement. Of course nobody these days has RS-232 on a PC/laptop so we all use USB to RS-232 converters to talk to the meter using USB. And he presto, now your marketing people claim you "can"  talk to the meter over USB! Of course you do  :palm:

Could you easily add USB, yes and no. No, if you mean a fully capable USB interface that is supported by the processor to for example mount and use USB sticks that you may plug in. The reason is that there are only 3 signal wires (tx,rx,gnd) that go from the digital board to the interface board and these are already RS-232 on TTL level. All the interface board does is convert these to RS-232 levels. It would need a relative large revision to change the hardware and firmware to do proper USB. Maybe they will do it eventually but I would not hold my breath.   But if you want to replace the DB9 with a USB socket, nothing stops you from removing the level converter chip and replacing it with one of the standard USB-to-serial chips (usually some chip from Prolific or clone) that are normally embedded in the ubiquitous adaptor cables. That gives you a physical USB port for the marketing people but that "USB" would not give you any more capabilities than what you get now with a cable converter, i.e.  a simple COMx or ttyUSBx interface.

The greatest humbug IMHO is the record function. Absolutely useless! Yes the meter can record up to 1000 entries manual or automatically but there is no way to download them. I tried all kinds of methods. And don't be fooled by the Owon PC software. In desperation, I finally gave in and went through the pain of installing it. I also rigged up a complex setup with my scope to sniff and protocol-analyse the exchanges between the OWON PC software and the XDM1041 to finally learn the secret how they access and download the recorded data over the serial interface. Turns out they don't. What they do instead is make a new recording (reading new measurements via SCPI and storing them in a text file on the PC). I think there is simply no way accessing remotely whatever you may have already recorded on the meter. Even more expensive OWON meters have nothing of that sort in their SCPI implementation. I think in those meters you can dump the recording on a USB-stick but that would require a "proper" USB interface and that (see above...)  |O
 

Offline rdl

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Re: OWON XDM1041 the unknown multimeter...
« Reply #61 on: June 03, 2021, 01:31:34 am »
What is the point of the big "Trigger" annunciation on the display? The little square next to it seems to blink in sync with display updates, but that seems pretty useless to me.
 

Offline theHWcave

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Re: OWON XDM1041 the unknown multimeter...
« Reply #62 on: June 03, 2021, 06:16:35 pm »
Yes, in the XDM1041 its only purpose is to show that the display is updated ... There is no setting or anything to influence trigger apart from the "run/stop" button but that is a simple hold (no auto-hold or anything fancy)
 
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Offline coromonadalix

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Re: OWON XDM1041 the unknown multimeter...
« Reply #63 on: June 04, 2021, 12:04:16 am »
Would it be better to call it  something like a "gate",  or "measurement in progress"   which could take too much space on the screen ...
 

Offline davebb

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Re: OWON XDM1041 the unknown multimeter...
« Reply #64 on: June 05, 2021, 05:30:30 pm »
Yes, in the XDM1041 its only purpose is to show that the display is updated ... There is no setting or anything to influence trigger apart from the "run/stop" button but that is a simple hold (no auto-hold or anything fancy)
Hi Great Youtube videos
it was me with the temp problem with my meter, as i said when the meter is cold the temperature Reading is very good
after about 10-20mins of the meter being on the reading reads 4-5d/c higher, what does your meter read with the k type
disconnected ?
can you please tell me is there a temp reference in the meter and what does it use to do this, or is the reference in side the meter HY3131 chip, i have re soldered the chip but this did not help,
also i took a photo of the ch 340 usb board that is fitted to mine, you can use it in your vids if you want to,
Thanks for your help ,
Dave 2E0DMB
« Last Edit: June 05, 2021, 05:52:15 pm by davebb »
 
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Offline Kleinstein

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Re: OWON XDM1041 the unknown multimeter...
« Reply #65 on: June 05, 2021, 06:51:56 pm »
The type K sensor is a thermocouple and it thus makes no realy sense to look at the reading, when open circuit. This would be effekted by the input bias and the relatively high input impedance (likely 10 M or even higher).
It make sense to look at the reading with shorted inputs. This should read the internal temperature used for the cold junction. Dave has a relatively recent video on this.
 

Offline davebb

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Re: OWON XDM1041 the unknown multimeter...
« Reply #66 on: June 05, 2021, 07:09:24 pm »
Hi Thanks for the info, is the internal temperature used for the cold junction in the HY3131 chip or is it external to the chip,
Thanks i am trying to find out what is going on as i do not rely want to send it back to china as the meter is working well apart from this problem ,
Thanks
Dave
 

Offline Kleinstein

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Re: OWON XDM1041 the unknown multimeter...
« Reply #67 on: June 05, 2021, 08:44:04 pm »
Connecting a type K thermocouple just to the banana plugs is always tricky, as the banana plugs are usually copper / brass or similar. So the cold junction would be somewhere out at the connector. So it really depends on how the connections are made and it could be just a poor probe quality. The test with just a copper short would be more reliable than with a real probe. Some banana cable are also not that great and could cause a few µV of offset if one connector gets warm.

Chances are there is some sensor near the COM terminal (due to isolation requirements it would be hard to measure at the other connector).
One could test this by using a short with a copper cable and than warm up the COM connector (e.g. touch / warm with the hand). The closer the sensor to the terminal, the faster it can react.

For an accurate reading a PT1000 or NTC temperature probe would be better. Thermocouple with just 4 mm connectors is more like a crude relative estimate with some extra uncertainty.

P.s. : The linked teardown pictures don't show an extra sensor near the connector. So likely the HY3131 internal temperature only - ideally with some offset in software.
« Last Edit: June 05, 2021, 08:57:32 pm by Kleinstein »
 

Offline davebb

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Re: OWON XDM1041 the unknown multimeter...
« Reply #68 on: June 05, 2021, 09:27:07 pm »
Hi Thanks for all that info, i have shorted out the input and yes temp reading is good but after about the same amount of time the temp goes up high about the same amount, just like it does with a probe, There is a relay in line in the circuit, so the next thing to try is to link it out to see if it is that,
Thanks Dave
« Last Edit: June 05, 2021, 09:29:23 pm by davebb »
 

Offline Kleinstein

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Re: OWON XDM1041 the unknown multimeter...
« Reply #69 on: June 05, 2021, 10:25:18 pm »
I don't expect the relay to be the problem.  Chances are the relay is a latching type and not getting really hot.

The more likely problem is that the whole meter gets warmer with time. With a copper short the meter should show the temperature of the connector(s). So some rise above the room temperature is correct. There is still a chance that the correction for the meter getting warmer is not correct (e.g. to much, as the chip likely heats up more than the connector).
With no sensor at the connector the meter can not reliably get that temperature - the cables can have quite some effect on the temperature at the connectors. So one can not expect a really good conpensation of the cold junction.

Besides the problem inside the meter, it is also the question where the actual cold junction is. Ideally it would be on the inside of the terminals, like the TC wire going all the way to the tip if the plugs or plugs made from thermocouple equivalent material. The more likely construction is having normal cheap plugs made from brass and thus a cold junction a bit outside. This could add some error, though likely less than 50% of the cold junction variations. So I don't hink the probe could explain a similator effect as with the short.

Is the thermocoule at least reading external temperature changes about right (e.g. some hot/cold water) ?
 

Offline davebb

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Re: OWON XDM1041 the unknown multimeter...
« Reply #70 on: June 05, 2021, 10:34:31 pm »
Hi yes it reads fine until about 10-20 mins and it follows another meter until it has been on for this time,
Thanks Dave
 

Offline theHWcave

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Re: OWON XDM1041 the unknown multimeter...
« Reply #71 on: June 05, 2021, 10:44:44 pm »
@Kleinstein:  I examined the board carefully and I don't think there is another sensor. I think they rely on the HY3131.

 I recorded the displayed temperature with shortened probes when the meter is turned on after being off overnight. Over 1 hour it climbed from 18.9 to 27 degC. But not smoothly. There were very distinct steps. This could be something else interfering as I was not paying attention, so I will repeat that again. Right now it shows 26.9 with probes shortened. With a K-type probe (borrowed from a BM235) it shows 27.7 The BM869S with a pretty good (=expensive) K-type probe shows 26.9 at the same location.

I will do some  more testing tomorrow



 

Offline davebb

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Re: OWON XDM1041 the unknown multimeter...
« Reply #72 on: June 05, 2021, 10:49:28 pm »
Hi Thanks
if you could run some more tests that would be good,
Thanks Dave
 

Offline wizard69

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Re: OWON XDM1041 the unknown multimeter...
« Reply #73 on: June 06, 2021, 12:56:08 am »
Thermocouple could junction compensation needs to happen as close to the cold junctions as is possible.    Doing so on the PCB might result in a significant error.   

The first thing that should be done is to determine where the cold junction sensor is.   As has been explained that should be relatively close to the banana jacks, if not it is a design fail.

@Kleinstein:  I examined the board carefully and I don't think there is another sensor. I think they rely on the HY3131.

 I recorded the displayed temperature with shortened probes when the meter is turned on after being off overnight. Over 1 hour it climbed from 18.9 to 27 degC. But not smoothly. There were very distinct steps. This could be something else interfering as I was not paying attention, so I will repeat that again. Right now it shows 26.9 with probes shortened. With a K-type probe (borrowed from a BM235) it shows 27.7 The BM869S with a pretty good (=expensive) K-type probe shows 26.9 at the same location.
This shift is excessive and could indicate a part failure or simply the cold junction sensor being it the wrong place.   I'm thinking hard here but if the cold junction sensor was heating up then I'm thinking the displayed temperature should be going down.     Generally the offset associated with the cold junction is subtracted from the millivolt value at the measurement point.

A short, zero millivolts, represents 0ºC for a K-type thermcouple.   You would then subtract the reference junction voltage but here is the problem, you don't have another junction in an all copper connection scheme.   It would be interesting to see the behavior of the meter with a K type TC at the ice point.   This would create the second junction to be compensated at the meter terminals.

If you have a room temperature of 20 degrees a shorted input should result in an approximate negative 20 reading.    This if there is no second junction to offset the reading.  In any event my mind is a big foggy here and I worked extensively with type T TC's in the past where the copper conductor eliminated one joint requiring compensation.   My point is that reading room temperature might not make sense with a short.
Quote
I will do some  more testing tomorrow

One thing to consider is air flow.   IF this is indeed a reference junction compensation problem cooling the unit down after it heats up should result in fairly fast response on screen.

In any event I may need to think more on this.   I'm not at work at the moment so I can't set up anything to test the idea expressed above.
 

Offline wizard69

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Re: OWON XDM1041 the unknown multimeter...
« Reply #74 on: June 06, 2021, 01:12:01 am »
As a follow up to the above post I remembered that my new EEVBlog meter does K type thermocouples and it indeed reads room temperature with the test lead shorted.    This is causing me a bit of confusion as it implies that they are adding the reference junction temperature to the reading.

It is getting late so I may end up sleeping on this.    As I've said it has been awhile since I was heavily involved in TC work and that was mostly with type T.  In this case though both TC are in very similar millivolt ranges at room temperatures.

in any event drift is the problem here.
 

Offline Kleinstein

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Re: OWON XDM1041 the unknown multimeter...
« Reply #75 on: June 06, 2021, 06:00:13 am »
The thermocouple probe gives 0 V if the TC tip is at the same temperature as the cold junction. So the cold junction temperature is added, not subtracted. The type K TC constant is relatively constant, so one can assume adding the temperatures. It actually is adding the calculated voltage to take into account a possible nonlinear TC response. Here the simple approximation of a constant thermopower should be OK.

So a copper short reads the cold junction temperature used by the meter.

The cold junction sensor away from the actual terminals is a weakness in the design, but with the normal banana plugs it is anyway difficult to get an accurate measurement. There is a good reason the for accurate TC readings they use special connectors.
Measuring the temperature at the volts input terminal would be very tricky with isolation.

The readings of 26.9 - 27.7 °C  for the different probes and with 2 meters are not that bad.  With the current warm weather and some self heating from the meter this sounds reasonable. Melting ice can be used as a reasonable reference temperature. The other simple test point is boiling water.

With the standard plugs one has to accept a few degree of uncertainty.  TC probes are not made for high absolute accuracy and the 4 mm plugs and CAT rating of the meters add another complication. The initial reading can be off, as the meter may need to warm up before getting good readings. With the sensor at the main chip this would be normal.  With turbulent air flow there can be some temperature variations at the chip. The heat up curve can be a bit more complicated than just a simple smooth exponential and the temperature reading my not be very frequent.
 

Offline theHWcave

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Re: OWON XDM1041 the unknown multimeter...
« Reply #76 on: June 06, 2021, 01:39:42 pm »
The OWON XDM1041 temperature weirdness
I did a few measurements this morning and here are the results. Note that all this about firmware version 1.2. The graphs were taken by polling the measured value via SCPI every second into a spreadsheet.
From the cold-start and warmed-up graph you can see that the meter looks at the internal temperature sensor every 600 seconds (10 minutes). During that time (about 3 seconds) the meter does not respond to SCPI polls, i.e. 3 polls time out but at the 4th one you get 4 results (i.e. it buffered the responses internally).  Note that this “pause” on SCPI every 600 seconds only happens if you are in temperature mode. If you are in millivolts for example there is no pause.

Interestingly, the very first temperature measurement after it updated the value it holds as cold-junction temperature is always a bit high. Not sure why. This you can clearly see in the warmed-up graph.

In temperature mode, the meter displays the “measured” value at the bottom of the display (what a brilliant idea! Seriously why don’t other meters copy that).  This allows an easy check if it is “doing the right thing”.
Example: With just cables to my millivolt source plugged in, but no external voltage applied, it reads 28 deg. and -0.02 mV Using the NIST tables / polynomials for K-type, 28 deg. corresponds to 1.122 mV.  This it stores as the cold junction offset (for the next 10 minutes).

If I now apply +1 mV to the input, the meter shows 52.7 deg.C and 0.98 mV.  The meter adds the 0.98 to the stored 1.122mV and gets 2.102 mV. According to the NIST polynomial equation that would be 51.9 deg.C. Ok so its off by 0.8 deg.  Maybe they use lookup tables instead of the reasonably complex maths. 

If I apply -1 mV to the input, the meter shows 2.8 deg. C and -1.03mV. Doing the same calculation, the resulting voltage is 0.092mV and the NIST value 2.3 deg C. Again, 0.5 deg. off  but I think in principle the meter is doing the right thing.

@davebb: If your meter shows the right value at startup but not some time afterwards, it seems it may not do its 600s refresh of the cold-junction temperature.  The best way to find out is to repeat the same test I have done for the cold-start graph and see if you get that staircase (or the spikes in the warmed-up) graph. You could use the OWON software and its recording function but I am not sure how it responds to the “pause” after 10mins. Better to use a small script and simply send every second: “MEAS1?<LF> “ and store the response
« Last Edit: June 06, 2021, 01:43:00 pm by theHWcave »
 

Offline theHWcave

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Re: OWON XDM1041 the unknown multimeter...
« Reply #77 on: June 06, 2021, 03:17:47 pm »
@davebb: coming to think of it. An easier way to check if the cold junction temperature is properly updated is to start the meter after it was off and cold with shortened probes and wait. Over 30-60 minutes, the temperature reading should increase (by several degrees) as it heats up internally.
 

Offline Kleinstein

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Re: OWON XDM1041 the unknown multimeter...
« Reply #78 on: June 06, 2021, 03:37:22 pm »
The rather slow update of the cold junction temperature is a bit anoying. So one has to essentially wait at least some 30 minutes for warm up.
In addition there seem to be a few point's that are off just after a update.

I wonder if one could force an update by switching between a mV rading and a temperature reading. If the meter does not measure the temperature in mV range it may do an internal temperature reading just after changing the function. At least with program control one could this way force the internal reading more often if needed.

 

Offline theHWcave

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Re: OWON XDM1041 the unknown multimeter...
« Reply #79 on: June 06, 2021, 03:53:34 pm »
A very good point and I tested that just now. Sadly the 10 minutes cycle to refresh the cold junction temperature reference seems to run independent of what mode you are in
 

Offline davebb

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Re: OWON XDM1041 the unknown multimeter...
« Reply #80 on: June 06, 2021, 04:21:40 pm »
Hi I have had my meter on for some time, it is reading 32.5c with input shorted , real temp in the room is 25c
i am now going to switch the meter of to cool down and then run a test with the easy dmm software recording
but it does look as this part of the meter is duff,
Thanks Dave
 

Offline Kleinstein

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Re: OWON XDM1041 the unknown multimeter...
« Reply #81 on: June 06, 2021, 04:56:31 pm »
The part around the connects would warm up somewhat. So 6 degree higher than room temperature may be actually right.
Even with a seprate sensor near the ground therminal there is still the problem if the other terminal is the same temperature. From the design good TC probes would have to have low thermal conductivity to the outside, so that the assuption of a temperature relatively close to the meter internal temperature is not that bad.
 

Offline davebb

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Re: OWON XDM1041 the unknown multimeter...
« Reply #82 on: June 06, 2021, 05:07:53 pm »
Hi
I do not think it is correct , it reads correct when cold, and with the probe it reads correct until it jumps after about 10-20 mins , i will log when it has been off for some time,
I will post the log soon,
Thanks Dave
 

Offline davebb

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Re: OWON XDM1041 the unknown multimeter...
« Reply #83 on: June 06, 2021, 06:15:49 pm »
The OWON XDM1041 temperature weirdness
I did a few measurements this morning and here are the results. Note that all this about firmware version 1.2. The graphs were taken by polling the measured value via SCPI every second into a spreadsheet.
From the cold-start and warmed-up graph you can see that the meter looks at the internal temperature sensor every 600 seconds (10 minutes). During that time (about 3 seconds) the meter does not respond to SCPI polls, i.e. 3 polls time out but at the 4th one you get 4 results (i.e. it buffered the responses internally).  Note that this “pause” on SCPI every 600 seconds only happens if you are in temperature mode. If you are in millivolts for example there is no pause.

Interestingly, the very first temperature measurement after it updated the value it holds as cold-junction temperature is always a bit high. Not sure why. This you can clearly see in the warmed-up graph.

In temperature mode, the meter displays the “measured” value at the bottom of the display (what a brilliant idea! Seriously why don’t other meters copy that).  This allows an easy check if it is “doing the right thing”.
Example: With just cables to my millivolt source plugged in, but no external voltage applied, it reads 28 deg. and -0.02 mV Using the NIST tables / polynomials for K-type, 28 deg. corresponds to 1.122 mV.  This it stores as the cold junction offset (for the next 10 minutes).

If I now apply +1 mV to the input, the meter shows 52.7 deg.C and 0.98 mV.  The meter adds the 0.98 to the stored 1.122mV and gets 2.102 mV. According to the NIST polynomial equation that would be 51.9 deg.C. Ok so its off by 0.8 deg.  Maybe they use lookup tables instead of the reasonably complex maths. 

If I apply -1 mV to the input, the meter shows 2.8 deg. C and -1.03mV. Doing the same calculation, the resulting voltage is 0.092mV and the NIST value 2.3 deg C. Again, 0.5 deg. off  but I think in principle the meter is doing the right thing.

@davebb: If your meter shows the right value at startup but not some time afterwards, it seems it may not do its 600s refresh of the cold-junction temperature.  The best way to find out is to repeat the same test I have done for the cold-start graph and see if you get that staircase (or the spikes in the warmed-up) graph. You could use the OWON software and its recording function but I am not sure how it responds to the “pause” after 10mins. Better to use a small script and simply send every second: “MEAS1?<LF> “ and store the response
My be they messed mine up with  firmware version 1.3.0 that mine has ?
Dave
 

Offline davebb

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Re: OWON XDM1041 the unknown multimeter...
« Reply #84 on: June 06, 2021, 07:36:29 pm »
Hi i have attached the log of the meter of the internal reading front ports shorted at the meter,
Thanks Dave
 

Offline theHWcave

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Re: OWON XDM1041 the unknown multimeter...
« Reply #85 on: June 06, 2021, 07:52:22 pm »
@Kleinstein: The only temp. sensor is the one inside the HY3131. Its physically a fair bit away from the probe sockets and not thermally connected other than through quite a bit of PCB material and ambient air inside the meter. That said, I stuffed an external k-type sensor into one of the sockets and measured the temperature which is within 0.5 deg. the value cold junction temp shown by the meter. I guess that is kind of acceptable (given the price etc)
 

Offline theHWcave

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Re: OWON XDM1041 the unknown multimeter...
« Reply #86 on: June 06, 2021, 08:07:48 pm »
@davebb
what a terrible format that OWON PC software produces....  :--

Besides that, the good news is that your meter behaves exactly like mine. Every 10 minutes the cold junction is updated.  :-+
18:47    25.6
18:57    jump to 29.7
19:07    jump to 31.2

So that part works as expected and the firmware did not do anything bad (or good)

Now with that established and the meter in a warmed-up state can you give:
1. the temp reading and the measure value shown on the display with probes shortened
then replace probes with K-type (the right way around ! and take care not to touch close to the tip)
2. he temp reading and the measure value shown on the display with the k-type in  and what value it should be (according to some other thermometer you have)

Thanks
 

Offline davebb

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Re: OWON XDM1041 the unknown multimeter...
« Reply #87 on: June 06, 2021, 08:48:17 pm »
Hi
The meter has been on for some time withe the input shorted it reads 33.4c 000.02mv, and 25.4 on another thermometer
with a k type it reads 34.6c  000.07mv, and 25.5 on another thermometer ,
When the meter is on from cold i had a reading with in 0.5deg c betwen meter with probe and thermometer
Thanks Dave
« Last Edit: June 06, 2021, 09:24:29 pm by davebb »
 

Offline theHWcave

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Re: OWON XDM1041 the unknown multimeter...
« Reply #88 on: June 06, 2021, 10:00:23 pm »
Very strange!  These values seem correct. That is, if the socket temperature (cold junction) is indeed 33.4 deg.C and the measured value with K-type is indeed 0.07mV then the readout should be 34.6 deg C. To see 25.5 in this situation, the measured value should have been -0.301 mV.  Are you sure this thermocouple is working and is a k-type? Also what are you using to plug it into the meter? Can you send a photo of the way the couple is plugged in?

Thanks
 

Offline davebb

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Re: OWON XDM1041 the unknown multimeter...
« Reply #89 on: June 06, 2021, 10:19:30 pm »
Hi i am using a k type with 4mm plugs from another owon OW18E handheld and the same with another one from another meter and with that meter is reads slightly lower then my room thermometer, if voltage reading is correct why does the internal temp in chip reading go so high as well after 10mins, did they use the wrong calibration settings at owon, and both read correct when the meter is cold ,
Thanks Dave
 
« Last Edit: June 06, 2021, 10:39:42 pm by davebb »
 

Offline davebb

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Re: OWON XDM1041 the unknown multimeter...
« Reply #90 on: June 06, 2021, 10:38:05 pm »
To test the internal chip sensor i used 2 good 4MM plugs and the copper core from some rg213 coax cable between the to plugs so is very short,
 The meter has been running a long time now and is reading 35.2 with the k type , and 33.4 c with the short,
the room temp is 25.5c
Thanks Dave
« Last Edit: June 06, 2021, 10:52:46 pm by davebb »
 

Offline Kleinstein

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Re: OWON XDM1041 the unknown multimeter...
« Reply #91 on: June 07, 2021, 06:16:48 am »
The socket inside the meter should get warm. So the 33.4 C for the short are plausible. The strange thing is the low voltage measured for the thermocouple. So it the the thermocouple working, e.g. showing about the right difference for something like boiling hot water or ice water.
The numbers shown would point to a failure with the probe or maybe the 50 mV voltage range. Chances are the temperature measuremetn would use the 50 mV voltage range.  So one could do a test with a more or less stable voltage in the 20-40 mV range and measure this in both the 50 mV and 500 mV range.
 

Offline davebb

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Re: OWON XDM1041 the unknown multimeter...
« Reply #92 on: June 07, 2021, 06:45:57 pm »
Hi thanks for the info yes the k type is working, it does not jump temp on any other meter  i have tested with other k types and get the same problem,
i have now tested with 30.842mv from a psu and when i ended the test it was 30.927mv showing at the end of the log file When i switch over to voltage,
and that was correct with another meter,
Thanks all for your Help
Thanks Dave Browne 2E0DMB
 

Offline theHWcave

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Re: OWON XDM1041 the unknown multimeter...
« Reply #93 on: June 07, 2021, 09:00:37 pm »
I am using a K-type that came with the BM235. It has 2x 4mm banana plugs on one side and the K-wire pair comes directly out of the other end. For my BM869S I use a specially made adapter that has 4mm banana plugs on one side and a small 2-pin socket especially for thermocouples on the other side. My RS-component K-type  thermocouples I bought for this meter end in those plugs that fit the sockets in the adaptor.

In both cases the cold-junction (i.e. the non-sensor end of the K-type wires) actually happens outside the meter.  Depending how “hot” the XDM1041 terminals are and how well the banana plugs conduct that heat, the cold-junction may be quite a bit lower in temperature than what the XDM1041 thinks it is. In handheld meters this seems to be less of a problem because they are seldom on for long periods and generally more power optimised. This means the inside temperature of a handheld is closer to ambient.

This could well be the problem of your meter which seems to run hotter than mine. I have never seen more than 28 deg after hours of operation but you seem to run at 31 or so.  It shows correct for the first couple of 10-minute cycles until it adjusts the cold-junction to 31 deg which is way higher than the real ambient temp.

The first question is why does it get hot inside? The power supply is always on, regardless of the power switch so that is not it. The HY3131 with the actual temp. sensor consumes max 0.5W and the processor even less. In the end I had to open the meter and examine it with a crude self-made thermal imaging camera (MLX90640 sensor & Raspberry Pi). The only thing that gets quite hot is a 1 ohm SMD resistor next to the LCD connector. When I turned the backlight to the lowest setting, the heat disappeared.

So here is a test you can do. Run the meter at the lowest backlight intensity and check if you getting better accuracy. I have done this now for 30 mins and the temperature has dropped by 2 deg.

Although I think mine is generally ok as long as I use the BM235 probe which probably gets warmed quickly through the sockets, I am seriously thinking of opening some of the “vents” at the back with a drill. They seem to be more style than function.
 
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Offline davebb

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Re: OWON XDM1041 the unknown multimeter...
« Reply #94 on: June 07, 2021, 09:16:36 pm »
Hi
ok i will try lowering the back light and see if that helps
but i did run the meter open and it did not make much difference,
Thanks for your help
Dave
 

Offline davebb

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Re: OWON XDM1041 the unknown multimeter...
« Reply #95 on: June 07, 2021, 10:37:02 pm »
Hi yes you are correct it has changed the temp by about 2 dg/c by turning the screen brightens to 0, and i have moved the meter in to free space only reading about 2.5dg/c high now,
Please let me know if you find anything more,
Thanks for your Help
Dave
« Last Edit: June 08, 2021, 06:20:08 am by davebb »
 

Offline Misk

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Re: OWON XDM1041 the unknown multimeter...
« Reply #96 on: June 09, 2021, 08:07:46 pm »
Sorry for my english. I buy OWON XDM1041 and I have a problem with it. Problem in this video https://www.youtube.com/watch?v=rcfSdUYxkVM. The measuring of megaoms resistors is bad and unstable. I think the HY3131 is bad. Can anyone measuring the 10MOm resistor on a analog board of XDM1041 near the HY3131 (conected to 5 pin from end). I measuring 8 MOm and the risistance change, when I repositing my body and other objects. When I touch the board it change to 6MOm. The resistor 10Mom is good. I test them separetly. I need to know, how the good HY3131 work.
The return of the device is expensive for me. Other function work satisfactorily for me.
« Last Edit: June 09, 2021, 08:09:31 pm by Misk »
 

Offline Kleinstein

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Re: OWON XDM1041 the unknown multimeter...
« Reply #97 on: June 09, 2021, 10:21:08 pm »
The resistor reading seems to change with the meter taken of the ground. This could indicate something like a problem with EMI or maybe too much mains hum.
 

Offline davebb

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Re: OWON XDM1041 the unknown multimeter...
« Reply #98 on: June 09, 2021, 10:30:19 pm »
Hi Have you tried a PT100 to see if that works ok, does the meter still use the same temp in the HY3131 for 10min cal
Thanks Dave
 

Offline theHWcave

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Re: OWON XDM1041 the unknown multimeter...
« Reply #99 on: June 09, 2021, 11:08:15 pm »
The meter was running the whole day today using the BM235 K-type probe with its sensor next to a PT100 which was connected to the 34401A. I recorded the values from both  every 30s over almost 10 hours. The XDM1041 was consistently about 1.8 deg. too low but followed the temperature variations exactly. This was using the lowest backlight.  When I plugged the same K-type into the BM869S (without changing anything else) it showed about 1 deg lower that the 34401A's PT100 reading. So I would say 1 deg error due to the K-type probe itself (totally expected) and 1 deg due to the XDM1041 thinking the ambient temp. is higher than it is. Although backlight is low, some things still produce a little heat and it builds up because there is very little airflow.  Next step (weekend probably) is to widen the cooling vents in the DDM1041 and see if I can get the internal temperature lower.

The PT100 is another story. I have a proper 3-wire one from RS-Components so reasonable quality.  Not sure if you are familiar with 3-wire PT100 but basically you need to eliminate the resistance of the wires to the sensor head. PT100 is using resistance and 100 Ohm = 0 deg. C. The change in resistance is very little from 100 to 110 Ohm is the equivalent of 0 deg C to over 25.5 deg C so you can see that milliohms count here. There are special circuits for 3-wire probes but I am using the fact that 2 wires are connected at the probe end. So if you use these and measure the resistance you get a value of 2x the resistance of the length of the probe cable. I use that to null the meter and then replace one of the wires  at the meter with the 3rd one (that goes through the probe).  And this is where the XDM1041 fails. You can null the PT100 probe in resistance mode, no problem. But when you go to Temperature mode and select PT100 it ignores the REL value for resistance and shows the value that includes the wire resistance.  REL in Temperature mode nulls the temperature value not the resistance.  Using PT100 on a XDM1041 iin temperature mode is useless unless you use an extremely short or very thick cable to the sensor head. I mean that is doable but why?  The alternative is to use the PT100 in resistance mode (with proper null of cable resistance) and convert the resistance to temperature by hand (or script when reading from SCPI). This  is by the way exactly what I have done for the 34401A because the 34401A has no PT100 mode so I am simply reading the resistance and convert that using the PT100 formula as long as you go only positive (> 0 deg C) its not too complicated.

# convert ohm to deg.C using PT100 probe
def PT100(ohm):
   TC = 0.00385
   A  = 3.9083E-03
   B  = 5.775E-07
   R0 = 100.0
   return (-A + math.sqrt(A*A - 4*B*(1-ohm/R0)))/(2*B)

Does it do the 10 minute - cold-junction update in PT100 mode? I have not tested it but I am almost sure it doesn't. I mean it may still do it in the background but since PT100 does not need the ambient temperature it should not show. But I will test it tomorrow and report
 
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Offline theHWcave

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Re: OWON XDM1041 the unknown multimeter...
« Reply #100 on: June 09, 2021, 11:16:29 pm »
@Misk
For anything above 100K or so, you must use LOW speed. Secondly AUTO RANGE is not reliable at high resistance values. Try manual range.  Using this I can measure 10 Meg with good accuracy

It is very similar to capacity mode. I find that > 1000uF you have to use manual range or you never get a good reading.
 
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Offline Kleinstein

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Re: OWON XDM1041 the unknown multimeter...
« Reply #101 on: June 10, 2021, 05:11:10 am »
Pt100 is problematic with 2 wires. 3 wire mode is usually not supportedd by DMMs. Bendch DMMs usually support 4 wire mode - though it looks like the XDM1041 does not. With 2 wire connections it would be better to use Pt1000 instead of Pt100.

The accuracy of thermocouples is often nor very good, but the error is usually more like a percentage of difference to the room temperatur. At essentially the room temperature there is not much error from the TC itself. There can be some error from the connectors, from lokal temperature gradients. It is more the PT100 sensor that can have an offset-error.
 
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Offline Misk

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Re: OWON XDM1041 the unknown multimeter...
« Reply #102 on: June 10, 2021, 06:13:32 pm »
@Misk
For anything above 100K or so, you must use LOW speed. Secondly AUTO RANGE is not reliable at high resistance values. Try manual range.  Using this I can measure 10 Meg with good accuracy

It is very similar to capacity mode. I find that > 1000uF you have to use manual range or you never get a good reading.
Thank you. I ask OWON support one week.  Finally I get a special firmware from OWON and the all problems are solved.
 
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Offline davebb

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Re: OWON XDM1041 the unknown multimeter...
« Reply #103 on: June 10, 2021, 07:01:24 pm »
@Misk
For anything above 100K or so, you must use LOW speed. Secondly AUTO RANGE is not reliable at high resistance values. Try manual range.  Using this I can measure 10 Meg with good accuracy

It is very similar to capacity mode. I find that > 1000uF you have to use manual range or you never get a good reading.
Thank you. I ask OWON support one week.  Finally I get a special firmware from OWON and the all problems are solved.
Hi do you up load the firmware with the rs232 / usb port,
Can you please post the new firmware and is there a loader program , Thanks Dave
 

Offline davebb

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Re: OWON XDM1041 the unknown multimeter...
« Reply #104 on: June 10, 2021, 07:26:41 pm »
Hi Misk
Have you tested with a K-type probe to test the Temp,
if you have does yours read ok ?, do you get a jump in temp after its been on for 10 mins?
what version firmware are you now using
Thanks Dave
 

Offline theHWcave

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Re: OWON XDM1041 the unknown multimeter...
« Reply #105 on: June 10, 2021, 08:45:28 pm »
Pt100 is problematic with 2 wires. 3 wire mode is usually not supportedd by DMMs. Bendch DMMs usually support 4 wire mode - though it looks like the XDM1041 does not. With 2 wire connections it would be better to use Pt1000 instead of Pt100.

The accuracy of thermocouples is often nor very good, but the error is usually more like a percentage of difference to the room temperatur. At essentially the room temperature there is not much error from the TC itself. There can be some error from the connectors, from lokal temperature gradients. It is more the PT100 sensor that can have an offset-error.

Totally agree with that, although you can use 3-wire as I described in my previous post with REL to null the wire resistance. Unfortunately the XDM1041 ignores the REL value for Ohms when using the PT100.  With PT100 the error caused by wire resistance can be significant. My probe has 0.262 Ohm (2-way) wire resistance. Without REL, this adds to the resistance of the sensor. At 5 deg C, that causes an error of 13%, at 10 deg.C still 6.5%, 20 deg.C 3.3%. Only for >70 deg.C will the error be 1% or less.  So for high temperature measurements, the PT100 is usable in the XDM1041, for room temperature sadly not (unless you change the sensor wires to have very little resistance).
 

Offline theHWcave

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Re: OWON XDM1041 the unknown multimeter...
« Reply #106 on: June 10, 2021, 08:48:23 pm »
Hi Have you tried a PT100 to see if that works ok, does the meter still use the same temp in the HY3131 for 10min cal
Thanks Dave
I tested this today and as expected, there is no 10min cal cycle in PT100 mode
 

Offline davebb

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Re: OWON XDM1041 the unknown multimeter...
« Reply #107 on: June 10, 2021, 08:53:22 pm »
ok thanks
it would be good to know what this new firmware that misk has now got and if it still does this,
Thanks Dave
 

Offline theHWcave

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Re: OWON XDM1041 the unknown multimeter...
« Reply #108 on: June 13, 2021, 09:32:23 am »
Yeah, same here. After I saw Misk's post, I send an email to OWON asking about it....  but no response (so far). I'll post if I hear anything

I did an interesting test yesterday using a Peltier element cooling an old heat sink = chunk of aluminium. I had a PT100, the unknown K-type I normally use for the XDM1041 and a known (RS-components) K-type which I use for my BM869S all attached to the same area on that heat sink.  Long story short, it seems as if the XDM1041 was much closer tracking the PT100 when it used the RS-components K-type. That one, RS stock# 409-4920  costs nearly £8 (incl. VAT) and is still only rated as +- 1.5 degC, so I'd imagine the unknown one to be much worse. Side note. To use the RS K-type (or other more professional sensors) you need a K-type adapter. I use the Brymen BKB32 for around £5 from Telonic
 

Offline davebb

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Re: OWON XDM1041 the unknown multimeter...
« Reply #109 on: June 13, 2021, 11:48:31 am »
Good afternoon
Thanks for the info, i hope you do get a replay  from owon
i will get a PT100
Thanks Dave
 

Offline davebb

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Re: OWON XDM1041 the unknown multimeter...
« Reply #110 on: June 13, 2021, 01:51:27 pm »
Hi i have just connected 99.5ohm and am getting -000.6c and it does not change after 10min so yes i will have to try a pt100,
does the K type respond faster to temp change,
do you know what software we can use to extract and load the firmware ,

Thanks Dave
 

Offline theHWcave

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Re: OWON XDM1041 the unknown multimeter...
« Reply #111 on: June 14, 2021, 08:52:11 pm »
I mentioned a few posts ago that there is no 10min cycle in PT100 mode...
Responsiveness depends a lot on the packaging. My PT100 sensor end is encased into some metal housing (like a short 6mm diameter pipe). That protects it well but makes it slower to respond than both my K-types which have the naked junction exposed.

The RS-components 409-4920 K-type I mentioned before has a  response time of 0.1s (datasheet). The PT100 (also RS) has no response time listed in the datasheet.

I am somewhat surprised you went for a PT100 not a "reputable" K-type. Unless of course you measure mostly high temperatures or got a probe with really short and thick leads. 

No idea how one would load firmware. I suppose it is possible that a certain button combination gets the processor into accepting firmware sent over the serial port but so far OWON has remained silent...

 

Offline davebb

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Re: OWON XDM1041 the unknown multimeter...
« Reply #112 on: June 14, 2021, 09:04:53 pm »
Hi i have not yet got a PT100, yes i did read that you said your meter did not do the 10min, but as mine is v1.3.0 i would test mine.
i only used a resistor, i hope that we get new firmware that also fixes this,
Thanks Dave
 

Offline kwass

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Re: OWON XDM1041 the unknown multimeter...
« Reply #113 on: June 16, 2021, 11:09:02 pm »
Dave said:
Quote
Just stumbled across this myself on ebay.
I kinda like the look of it!
Shame it's not battery powered.

But mine is!  I took advantage of all the USB power stuff available for cheap and replaced the internal 5V supply with a Qi charged LiPo cell.  I used this https://www.amazon.com/gp/product/B07M6CRQ71/ Qi receiver on Amazon along with this https://www.amazon.com/gp/product/B08GWTBD3T/ charger/booster module.  I used a large Qi pad https://www.amazon.com/gp/product/B07PYQQ1R7/ that the meter fits nicely on and has an "active" green LED in front.

While not necessary I added a small voltage meter so that I could see the change state of the LiPo cell all the time through the back window I installed in place of the IEC socket.  Also I installed threaded inserts to make removing the cover easier.

While I keep the meter on all the time, when it's "off the Qi pad" battery life is around 10 hours at full brightness, measuring volts, using a 3000mAh LiPo cell.  If you reduce the brightness to the minimum setting, it will last a full day.
« Last Edit: June 16, 2021, 11:14:16 pm by kwass »
-katie
 
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Offline theHWcave

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Re: OWON XDM1041 the unknown multimeter...
« Reply #114 on: June 17, 2021, 08:44:15 am »
@kwass: what a great mod! Very nice.

Can you tell me where you got these threaded inserts from? The number of times I open mine would make this a worth-while addition...
 

Offline kwass

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Re: OWON XDM1041 the unknown multimeter...
« Reply #115 on: June 17, 2021, 02:52:48 pm »
I used M2 size threaded inserts https://www.amazon.com/gp/product/B07LBQFNQD/ and melted them into the mounting posts.  Just takes a second but make sure that they are level.  I used M2 screws from this set https://www.amazon.com/gp/product/B07W5J4WC9/, you'll need some flat washers to match the width of the recessed case hole.

-katie
 
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Offline BugCatcher

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Re: OWON XDM1041 the unknown multimeter...
« Reply #116 on: June 17, 2021, 03:16:23 pm »
Hi kwass,

battery based is an excellent feature!
My private "MiniLab" is 1.4m x 1.4m. I had already a lot of trouble with interference from switched power supplies and a DECT-phone-base below the desk.
Do you really use the XDM1041 during active charging? Did you observe any interference from the Qi pad (e.g. high impedance measurements)?
Active Qi pad on a lab desk ... I would expect a lot of trouble!
 

Offline kwass

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Re: OWON XDM1041 the unknown multimeter...
« Reply #117 on: June 17, 2021, 04:25:05 pm »
Do you really use the XDM1041 during active charging? Did you observe any interference from the Qi pad (e.g. high impedance measurements)?
Active Qi pad on a lab desk ... I would expect a lot of trouble!


Yes, I do use it during active charging all the time and I've not seen any interference from the Qi pad at all -- even on high resistance (10M+ ohm) measurements and sub-uA measurements.  The Qi receiver ships with a stick-on magnetic shied and I've installed that behind the receiver coil, that might be helping a bunch.  Keep in mind that this meter has absolutely no internal shielding and it was designed with a switching power supply almost touching the main PCB and it works fine.

I thought that about the same potential issue before I started this project and did a bunch of testing before any modifications, just to be sure it would work fine.

No doubt the Qi pad adds a lot of noise to the local RF environment, but so do many switching power supplies on my bench that operate in the same frequency range.

-katie
 

Offline theHWcave

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Re: OWON XDM1041 the unknown multimeter...
« Reply #118 on: June 20, 2021, 09:35:09 pm »
A quick update. OWON has sent me a firmware update ! :-+
You need to install a special uploader program on a Windows PC, connect the XDM1041 via serial port, then point the uploader at the firmware binary, initiate the upload on the PC and turn the XDM1041 off and on. Obviously the meter sends a special message during bootup (when the screen shows the progress bar) to the uploader. The uploader detects this and sends the new firmware in chunks to the meter and then confirms whether it was successful. Instead of version 1.2, my meter now shows 20210525 (obviously a date) as a version

In the 1 hour playing with it so far, I have not seen anything really different. Maybe the meter redraws the screen slightly faster but I can't really vouch for that. I did test capacitance mode in auto range mode and it is as bad as before (need to use manual range for >500uF ) and the hick-up every 600s in KITS90 mode is also still there.
I have asked for a description of the changes and also if I can share the firmware. Will report on responses.
 
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Offline davebb

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Re: OWON XDM1041 the unknown multimeter...
« Reply #119 on: June 21, 2021, 01:09:00 pm »
Hi
This is great news,
I hope that they do let you post it, i would like to try it , to see if it helps my High Temp reading
Great video ,looking forward for the next one,
Thanks for letting us know
Thanks Dave
 

Offline theHWcave

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Re: OWON XDM1041 the unknown multimeter...
« Reply #120 on: July 06, 2021, 05:55:20 pm »
A list of all SCPI commands for the XDM1041 as far as I have discovered and tested them

Regarding firmware 25052021: its has issues on SCPI. For some reason, the XMD1041 now responds to every command that isn't by itself returning something with the string OK\nOK\nOK\n  (the \n being new line control characters). It does that even if you send nonsense like "hello world".  :palm: I think that change is the reason that the DMMEasyControl Windows software you can download from OWON to remote-control their multimeters can't change functions anymore.  The SCPI commands still work but your software now needs to deal with that nonsense response. Therefore I would not recommend this firmware change. :--
 
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Offline davebb

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Re: OWON XDM1041 the unknown multimeter...
« Reply #121 on: July 10, 2021, 04:19:26 pm »
Hi i have just been playing with my meter, i have been compering it against a Fluke 189 that my old work mate gave me as he has just finished work for good as he is now 70 years old he also gave me a load of crimp tools and 2c Metcal soldering irons and a box of tips for them, He said that there was a meter in the box , but i did not expect a fluke 189 in great condition, i worked with him 13 years ago, i have not seen him for about 8 years, so it is good to keep in touch by phone  :-DMM ,
the owon readings for dc voltage and resistance are very close to the fluke but what i did find is the dc current reading was out a bit, at 10 amps it was reading about 400ma low,
could this be corrected in the firmware ?
I do love the new to me fluke 189, peaple are still asking £370-400 on ebay for them,
Thanks Dave   
 

Offline Kleinstein

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Re: OWON XDM1041 the unknown multimeter...
« Reply #122 on: July 10, 2021, 05:03:21 pm »
The 10 A ranges on relatively cheap meters and also with some of the better hand-helds can suffer from heating of the shunt. So especially at a high current applied for a longer time, the reading may no be very accurate with both meters. It may be better to compare the 10 A range at a low current, like 2 or 3 A. So less heating and likely a more accurate reading.

The calibration procedure can likely adjust the skale factor for the 10 A range. With a modern meter this is done in software an not with an old style trimmer. Usually the factory calibration should be better than 4%, even with an OWON brand. The calibration procedure may not be openly available and may effect other ranges too - so nothing one would like to call if not absolutely needed.

The 10 A range on the fluke may no be perfectly protected by the fuse, so it may have suffered over years of use. So while it is a Fluke, I would not call a reliably reference for a recalibration. It is no clear which meter is out more.
 

Offline davebb

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Re: OWON XDM1041 the unknown multimeter...
« Reply #123 on: July 10, 2021, 05:31:47 pm »
Hi
it is the owon that is reading low, not the Fluke, The Fluke is perfect, i did compare the meters at a low current,500ma and up, i have Klunkin load ,
The owon reads low on the current range from mili-amps to 10amps and with 10 amps the owon is reading 9.6amps 400mAmps and 200ma low on 5amps load, i can leave 10amp on it and it does not change so i dont think it is heat
Thanks Dave
« Last Edit: July 10, 2021, 06:08:59 pm by davebb »
 

Offline theHWcave

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Re: OWON XDM1041 the unknown multimeter...
« Reply #124 on: July 11, 2021, 09:56:54 am »
How strange. My Owon was within 0.02% of the BM869S for DC current from 1A all the way to 7.5A (which is as high as I could test). The BM869S is rated to 0.5% for current  (same as the XDM1041 and the Fluke 189 for that matter).  From 500mA to 1A it was within 0.04% of the Agilent 34401A and from 1mA to 100mA witihin 0.02% of the Agilent 34401A

Even if we assume that the Fluke is reading 0.5% too high, i.e. it shows 10A when the true current is only 9.95A and the Owon 0.5% too low so that it would read the same current as 9.9, your result  of 9.6 on the Owon is way out of spec.

Also the XDM1041 spec says that for >7A you should measure for a max of 30 seconds with 30 seconds off afterwards. Especially if you are ramping up the test current slowly, say to test the meter in 0.5A steps, that heat & time limit is easily exceeded as heat is of course accumulative.  The Fluke has a similar time restriction but only for >10A I believe.

Kleinstein has a valid point here and hopefully nothing got permanently damaged during your earlier tests. To exclude heating effects you should run accuracy tests for higher currents from cold, both meters in series and off for some time, and compare the readings in the 1st 30 seconds.

 

Offline davebb

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Re: OWON XDM1041 the unknown multimeter...
« Reply #125 on: July 11, 2021, 12:02:54 pm »
Good afternoon
The flukes 189 spec say 10A continuous and 20a for 30sec
The fluke is measuring well against my load and psu amp meter and all other meters , 
anyway the shunt wire has a lot of solder on it on the shunt/ component side so i wicked some off and moved it a bit and now i am getting a reading of 32.5ma high at 5A, and 65ma high at 10A, I could Play with it some more but i am happy to leave it there,
Thanks Dave
 
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Offline theHWcave

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Re: OWON XDM1041 the unknown multimeter...
« Reply #126 on: July 11, 2021, 03:50:24 pm »
Very interesting. I never thought a bit of solder could have that much of an effect, I mean assuming it did not "climb" up the shunt itself. So before the shunt resistance was lower than it should have been and the meter was under-reading. Now it seems pretty much spot on (within tolerances).  Glad that its working now.

At the moment I am struggling with a similar problem for one of those cheap panel meters that measures DC volts & amps. The amp reading is way too high even when adjusting the trim-pot all the way down. I experimentally added a parallel shunt of 0.2Ohm and that got it nearly there. After your experience maybe I should add more solder to the shunt? I am very tempted to try that.
 

Offline davebb

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Re: OWON XDM1041 the unknown multimeter...
« Reply #127 on: July 11, 2021, 05:09:27 pm »
Hi
Yes, after how much difference the solder getting wicked up the legs of the shunt so yes the solder did climb up the shunt legs,i should have taken a photo, there was a lot of solder on the legs ,
i may well try and get it a little bit closer, but it is working well,
try tinning your shunt,you wont need much solder on there, you can always use solder wick to clean it back off
In a way i wish i had sent the meter back before playing with it, because of the temperature problem ,
it does seem strange how this got past there cal and QA, as the current was way out of spec,
i got a owon ow18e h/held meter to use at work as it has bluetooth and that is ok for £45, i work on a car x-ray unit it was drive thru, now we have it on a conveyor system controlled by a plc with 4x 3ph motors each with 500nm of torque,
we run the xray gen at, 250kv at 3ma ,so with bluetooth i dont have to get to close when testing,
Thanks Dave 
« Last Edit: July 11, 2021, 06:46:20 pm by davebb »
 

Offline coromonadalix

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Re: OWON XDM1041 the unknown multimeter...
« Reply #128 on: July 12, 2021, 07:55:34 am »
Be careful,  i've seen in the past some obscure ways to calibrate a shunt with added solder on it. Not a the pcb / shunt junction but on the "wire itself"   ??
« Last Edit: August 25, 2021, 06:58:11 am by coromonadalix »
 

Offline Kleinstein

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Re: OWON XDM1041 the unknown multimeter...
« Reply #129 on: July 12, 2021, 09:17:44 am »
Adjusting shunts by adding solder and removing matrial with a file was common in the old days of analog meters and early DMMs. Adding solder, especially in the center of the shunt can alter the TC as the solder resistance contributes and there is also some alloying (e.g. tin is incorporated into the base material).

Modern meters usually use numerical cal factors and thus calibration by a software constant.

I would be a bit careful in assuming that a used Fluke handheld DMM must be accurate. Usually the factory calibration is no that bad. There can be rare exceptions, like there can be damaged DMMs.
 

Offline davebb

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Re: OWON XDM1041 the unknown multimeter...
« Reply #130 on: July 12, 2021, 09:40:10 pm »
Hi My fluke reads fine the same as all of my good meters, It is the  OWON XDM1041 that was a long way out but better now
i think they have missed some of the cal at the factory as my temp is way out as well,
i should have sent it back to china to banggood but if i do any temp logging i can now use the fluke,
Thanks Dave
 

Offline markderlo

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Re: OWON XDM1041 the unknown multimeter...
« Reply #131 on: October 08, 2021, 05:02:47 pm »
post you email address or email me at ksmail9 AT protonmail.com and I will email you manual in PDF form
 



Offline J_A_F

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Re: OWON XDM1041 the unknown multimeter...
« Reply #134 on: October 16, 2021, 11:45:48 pm »
Hey Everyone,

I just bought one of the new revisions of the XDM1041 with USB, and I gotta say, not the most intuitive thing to set up as far as the control software goes.

Figured I would share what I did in case anyone has had the same trouble as me, or to save some poor soul in the future...

1. If you get one, ignore the install instructions, they don't configure the driver correctly, and nothing works. do the following:
   1.1 Install NI VISA (got it working on newest release, 21.0)
   1.2 Install CH340 drivers (the serial device used in the XDM1041). Sparkfun has an article pointing to them:https://learn.sparkfun.com/tutorials/how-to-install-ch340-drivers/all
   1.3 Install the DMMEaasyControl software
2. Next, when you open up the control software, click control->connect in the top left hand corner
3. Once it is open, choose "Via COM" instead of USB. Nothing ever pops up for USB
4. It should pop up a choice like "ASRL3(DMM) (mine is configured to be COM port 3)
5. Press ok and you should be good to go

Like other people have mentioned, software isn't the best, but it works, does data logging, ect. so hopefully this helps someone!

Also, if anyone had better luck let me know, I feel like this is a bit ridiculous
 
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Offline robdejonge

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Re: OWON XDM1041 the unknown multimeter...
« Reply #135 on: October 20, 2021, 04:00:08 am »
The form factor of this dmm is what makes it appealing to me. Like some others, I have a small shelf right over my work surface and it's great to be able to just glance up at my dmm and scope. A 'proper' bench dmm would move to a shelf quite a bit higher, which is the main reason I hesitate to get something like that until I can build a deeper bench.

The YouTube review videos theHWcave did were very insightful (thank you!). The voltage range issue is indeed odd, the bigger brother XDM2041 does not seem to have that issue. Other than that, and based on this thread, this seems to be a pretty decent electronics bench meter!

I do have a few questions ...
  • Burden voltage: has anybody had a look at this? I mostly play with 0-5V and 0-1A stuff, so it can be a major pain. My current meter drops the voltage by 142mV at 100mA, which is not too bad.
  • Software: although a Mac fanboy, I run Debian on my bench computer and so wonder if there is any software available on there which I can use to control / read this mm. Does anybody have any experience? Using software to do data logging is a major reason I'm looking at this.
  • Bar graph: I like me a nice bar graph, but I believe this meter does not have one - correct? I've recently been looking at power supplies which are showing a line graph over time, but I guess I would have seen that mode if it was present. I know, could use my scope.

Might sell my current meter and order this on 11/11 if there is a good deal.

Thanks for your comments.
« Last Edit: October 20, 2021, 04:14:39 am by robdejonge »
 

Offline kwass

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Re: OWON XDM1041 the unknown multimeter...
« Reply #136 on: October 21, 2021, 03:00:44 am »
  • I measured the current shunts: 500uA/5mA = 101 ohms, 50mA/500mA = 1.2 ohms, 5A/10A = 0.02 ohms.  So on the 500mA range, 100mA would be 120mV drop.
  • It's pretty standard SCPI, so I'm sure you could find some software for Debian.
  • Unfortunately there's no bar graph.
-katie
 

Offline robdejonge

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Re: OWON XDM1041 the unknown multimeter...
« Reply #137 on: October 21, 2021, 03:25:58 am »
Thanks for checking that. This is an interesting meter indeed, with a relatively low burden voltage like that!
 

Offline Kleinstein

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Re: OWON XDM1041 the unknown multimeter...
« Reply #138 on: October 21, 2021, 07:05:12 am »
The burden voltage for the 5 and 500 mA range is not low - it is more on the high side. The burden is low for the lower of the 2 ranges. The 20 mOhms for the 5/10A range is low - it this range with a fuse. Quite often a proper fuse has a comparable or even higher resistance. So part of the burden in the 500 mA range is the fuse and with this in mind the value is not that bad.

For a low cost meter it still makes sense to have few shunts and share one of 2 ranges each.
 

Offline robdejonge

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Re: OWON XDM1041 the unknown multimeter...
« Reply #139 on: October 21, 2021, 08:25:31 am »
Hm, okay.

So the way I look at this is that the maximum burden voltage would be 660mV. My existing meter is a Holdpeak HP-770D and has a burden voltage of 142mV @ 100mA and as a 42,000 count meter would peak at 596mV burden voltage. I'm happy to be corrected, because I've been wondering if this is the right way of calculating that.

In this overview, only the EEVblog meter has a max burden voltage that is impressively low. Not pushing back on your statement, just explaining why this novice thought 500-600mV was low.
 

Offline robdejonge

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Re: OWON XDM1041 the unknown multimeter...
« Reply #140 on: October 21, 2021, 08:32:55 am »
The Holdpeak HP-770D that I currently use is sort of ok for me. Reviews seemed to indicate it was within spec, and performing quite ok. And I've been happy with it until now.

The reason I'm looking at the XDM1041 is not so much for added accuracy (it does have smaller tolerances than the Holdpeak, and a slightly higher count), but more so because 1) it is a bench meter, I wouldn't be carrying it around; and 2) it supports data logging, which would let me monitor things over longer periods of time.

I'd try to sell my Holdpeak, although the market here has lots of cheap multimeters so I'm not sure I'd be able to.

Generally speaking, I can't seem to make up my mind between "it's worth spending $100 on this new meter" and "you don't need this new meter"  |O

So if anyone has arguments either way, please do share! :)
 

Offline HKJ

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Re: OWON XDM1041 the unknown multimeter...
« Reply #141 on: October 21, 2021, 09:11:17 am »
So the way I look at this is that the maximum burden voltage would be 660mV. My existing meter is a Holdpeak HP-770D and has a burden voltage of 142mV @ 100mA and as a 42,000 count meter would peak at 596mV burden voltage. I'm happy to be corrected, because I've been wondering if this is the right way of calculating that.

Typically handheld DMM's uses 100ohm, 1ohm & 0.01ohm as current shunts with two ranges for each shunt and the high uA & mA range will have a voltage drop across the resistor similar to the high mV range. For the 1ohm & 0.01ohm there is also the fuse to account for, it will about double the resistance for the 1ohm shunt, i.e. the burden voltage will typically be about twice the high mV range (This means about 1.2V for a 6000 count meter at 600mA).
A few meters are different either using lower shunt values or moving the high mA range to the 0.01ohm shunt (GW121)


2) it supports data logging, which would let me monitor things over longer periods of time.

If you want to log on a computer, try checking TestController, it support a lot of different meters (Not XDM1041 yet). There is a long thread about it here: https://www.eevblog.com/forum/testgear/program-that-can-log-from-many-multimeters/
 

Offline Kleinstein

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Re: OWON XDM1041 the unknown multimeter...
« Reply #142 on: October 21, 2021, 09:28:08 am »
The burden drop is often the same as the lowest mV range, as the mV range is used to measure the votlage at the shunt. With the older 2000/20000 count meters that was 200 mV. The meters with a 500/600 mV  range as there lowest have slight problem here. The burden would be quite hight an in addition the heat produces with 600 mA and 600 mV is already quite a lot.
In analog times the internal meter movement often got away with even less and a burden voltage of some 100 mV was more typical.
 

Offline HKJ

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Re: OWON XDM1041 the unknown multimeter...
« Reply #143 on: October 21, 2021, 10:30:57 am »
The burden drop is often the same as the lowest mV range, as the mV range is used to measure the votlage at the shunt.ore typical.

No, it is the highest mV range (200-600mV) for high uA and mA, if the meter has a low mV range (20-60mV) it is used for the low uA and mA range. If the low mv range is missing the internal x10 amplifier if not used for mV, only for current.
 

Offline theHWcave

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Re: OWON XDM1041 the unknown multimeter...
« Reply #144 on: October 31, 2021, 11:20:53 pm »
Have a look at my 4 part detailed review of the OWON XDM1041 . I also wrote some python software for logging (works on Linux and Windows) you can download from my Github page https://github.com/TheHWcave/OWON-XDM1041. This link also contains my documentation of the SCPI remote control commands implemented in the XDM1041 (quite comprehensive for what you pay).
The XDM1041 has its flaws. The main one is that by default its slow (but very accurate). It allows you to select faster speeds (sacrificing some accuracy) but you have to do that every time it is powered on (it doesn't remember that setting). Oh and the auto-ranging on capacitor measurement is not working well. If the XDM1041 is your only way to measure capacitance, buy another meter.  And did I mention that supporting PT100 temperature probes is well intended but useless because of the way REL mode is implemented for temperature. (K-type works better but has its own interesting quirks, watch the video or read my earlier posts on the XDM1041)...
Besides the XDM1041, I have an Agilent 34401A, Solartron 7150+ , HP3478A, BM869S, BM235 and a couple of other handhelds but the XDM1041 has become my most often used meter for repair work on the bench because its so convenient, small, and always on.
 
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Offline robdejonge

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Re: OWON XDM1041 the unknown multimeter...
« Reply #145 on: November 01, 2021, 04:31:47 am »
Besides the XDM1041, I have an Agilent 34401A, Solartron 7150+ , HP3478A, BM869S, BM235 and a couple of other handhelds but the XDM1041 has become my most often used meter for repair work on the bench because its so convenient, small, and always on.

That says a lot!
 

Offline robdejonge

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Re: OWON XDM1041 the unknown multimeter...
« Reply #146 on: November 01, 2021, 04:54:37 am »
Why does the meter require a function switch between mV and V for the VDC and VAC measurements? 

I recently saw a comparison of the XDM1041 and XDM2041 by Tony Albus
https://youtu.be/ZVDJSa3pxrY

The big brother of the two does not have the weird "function switch" requirement. But it seems to be using the same software or at least software framework. I'm curious what would necessitate the requirement of such a switch in the software. Is there a hardware reason? Or could we (let's not hold our breath!) eventually see Owon correct this issue in a firmware update?
 

Offline theHWcave

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Re: OWON XDM1041 the unknown multimeter...
« Reply #147 on: November 01, 2021, 08:09:55 am »
You are right, there isn't a hardware issue for that as far as I can see. At least for volts... It needs to do the same for current but there the reason is that A and mA/uA use different input sockets.  Could be something with the HY3131 front end? But nothing that the firmware could not fix.  Does Dave's 121GW do the same thing? It has the same front end chip.  OWON is sluggish at best responding to bug reports. What I hope is someone writing completely new software. This meter looks to be very hackable, since the front end used just an SPI interface and I think 2 discrete signals to drive relays
 

Offline Kleinstein

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Re: OWON XDM1041 the unknown multimeter...
« Reply #148 on: November 01, 2021, 10:07:49 am »
The separate mV and V ranges are a bit odd. It could be just avoiding the very long list of voltage ranges, that may not fit the screen. This should be a SW only issue.

It is interesting that the reading rate via the PC interface is quite a bit higher than with the updates on screen.

For the K-type thermocouple it does not really mater if the temperature is ITS90 or a different curve - the differents are so much in the details not even the 34401 with a PT100 may notice.
 

Offline ciccio

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Re: OWON XDM1041 the unknown multimeter...
« Reply #149 on: December 17, 2021, 03:01:35 pm »
I received my meter form Banggood yesterday.
First impression was positive, but when I checked  temperature measurement, I discovered that readings from a know good PT100 vere off, sometimes very off.   Reading increased slowly from 21 to 160 °C
My resistance box was not available,  so I checked at three resistance values,  and it was almost correct at 0, 100, 200 ° C.
Will check later with a better decade box.
As for thermocouple, the data sheet says K type, but the meter allows to select  "LOAD"  (why Load and not Source? ) as PT100 and KIT90 TC,  which I discovered being a new designation for K type.
With a known good TC, it seemed to read correct values.
I will examine cold junction compensation as soon as I'l  have a free evening.

The software installation was a nightmare,    I will try next week on a  Windows 10 PC.
My Windows 7 work machine seems to be allergic to   N.I. VISA32 installation.
I had the same problem with the software for a  JUNTEK function generator.
Best regards

 
Strenua Nos Exercet Inertia
I'm old enough, I don't repeat mistakes.
I always invent new ones
 

Offline BugCatcher

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Re: OWON XDM1041 the unknown multimeter...
« Reply #150 on: December 29, 2021, 04:57:36 pm »
theHWcave


Received my XDM1041 a few days ago (running V3.0.1 SW). During waiting for delivery was enough time to screen all available information.
Found interesting discussions regarding different types of temperature sensors.
Regarding PT100 sensors I found following arguments:
- calculations for temperatures < 0°C are more challenging
- unwanted cable resistance is adding huge errors at low temperatures (around °0C)

Regarding temperatures < °0C:
Calculation requires 3rd-order polynom (pos. temperatures only 2nd-order)
What happens when we simply ignore the 3rd-order coefficient "c"?
    at -100°C   an additional error of 0.2°C
    at  -50°C   an additional error of 0.02°C
    -> see first diagram ...  (including tolerance band for class A sensors)

=>  extreme unlikely that "home lab" applications will ever face temperatures below -50°C
=>  second order correction is sufficient! No need to block calculation for <0°C!


Regarding impact of cable resistance:
I calculated the impact of an given resistor (0.262Ohm). Precise calculation based on the 3rd order polynom.
- impact nearly flat, no singularity around 0°C
- simply subtract 0.7°C for a "good enough" correction  (rule of thumb: subtract 2.6°C per Ohm, perfect at 50°C)
   -> see second diagram
   -> there is no problem for bench applications without extreme cable length

During ordering PT100 sensors I found that there are also PT1000 devices!
Price for class A PT100/1000 unpacked sensors is below 2€ (e.g. Reichelt in Germany)
-> PT1000 reduces the impact of the unwanted resistance by one magnitude (green line)!
Problem:
XDM1041 is not supporting PT1000!   ...   Why? It's a huge benefit with nearly no effort (measured resistance divided by 10)!
The only solution is an external PC-SW with a very simple modification of the PT100 algorithm.
e.g.   XDM1041 utility from theHWcave ... btw: this is an impressive piece of work!!!
       Another idea: SW-feature to enter the cable resistance manually (no need for a 3-wire cable!)
                     ... only need for a one time resistance measurement at known temperature (e.g. 0°C ice-water)!

I tried to install the utility on a Windows10 system running Python 3.10 ... I failed!
What must be preinstalled? Did it ever work on Windows10?

Regarding comparison of Thermocouple/PTxx ... I found an interesting link:
https://tmseurope.co.uk/applications/thermocouple-rtd-colour-codes-tolerances
-> Below 400°C PTxx class A shows always the best precision!

My own preference is PT100/1000:
- low price
- good performance
- heading for PT1000 with external SW
- full precision after cold start ... no trouble with reference junction block
- only negative point:  TCs can handle higher temperatures

 
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Offline theHWcave

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Re: OWON XDM1041 the unknown multimeter...
« Reply #151 on: January 02, 2022, 06:44:58 pm »
For anyone interested, I have put the OWON Windows tool to upgrade the firmware of the XDM1041 as well as the firmware version OWON sent me (apparently V2.1.2 however it shows as 20210525) on my github page. The tool should be able to upload other firmware versions as well.

You can download it (in binary chunks) here: https://github.com/TheHWcave/OWON-XDM1041 with instructions in the readme file to reassemble the .ZIP file
(the reason for breaking it into chunks is the file size limit on Github)

To be clear, this is OWON's software but they gave me permission to post it. Don't complain to me about the quality of either the upgrade tool or the firmware please  ;D

From the same place, you can download my own software (happy to accept suggestions on that) to log data from the XDM1041 on a PC (Linux or Windows), including a mode to properly use a PT100 sensor to measure temperature.
 
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Offline BugCatcher

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Re: OWON XDM1041 the unknown multimeter...
« Reply #152 on: January 04, 2022, 01:41:33 pm »
XDM1041 Continuity Test

I had the impression that the response time is related to the XDM1041 "beep-threshold".
All existing evaluations regarding "speed of continuity beep response" are based on "hectic moves" combined with gut feeling!

I would like to propose an objective test method
- a function generator (square wave, 1Hz, variable duty cycle)
- a "contact" controlled by the function generator
      there are two options
       - a FET, I used a 2N7000 (2.1Ohm on resistance)
       - a reed relais (typ. 0.15Ohm on resistance, switching time about 1ms)
- I also increased the "on" contact resistance by adding different serial resistors (10, 30, 100Ohm)

Measurement procedure
Increase the "on" time by changing the duty cycle of the square wave
- first you hear single beeps (not every second)
- increase "on" time until you hear every second a beep
    -> this is the minimum time for the reliable detection of "contact"

The diagram shows my results for the XDM1041
- response time is heavily impacted by the "threshold resistance"
- high threshold gives you very fast response
- the setting of the threshold value depends on your application!

I tested also an UNI-T 804
- fixed threshold (40Ohm)
-  2.1Ohm 180ms
   10Ohm  170ms
   30Ohm  170ms

What about other multimeters?   Now we can compare!


Conclusion:     no longer need for "hectic moves"
   
 
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Offline HKJ

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Re: OWON XDM1041 the unknown multimeter...
« Reply #153 on: January 04, 2022, 02:24:09 pm »
All existing evaluations regarding "speed of continuity beep response" are based on "hectic moves" combined with gut feeling!

Not really, I have reviewed a lot of multimeters where I used something similar:

More about it: https://lygte-info.dk/info/DMMTesterACSwitch%20UK.html

My Reviews: https://lygte-info.dk/info/DMMReviews.html
 
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Offline BugCatcher

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Re: OWON XDM1041 the unknown multimeter...
« Reply #154 on: January 06, 2022, 09:44:10 pm »
Good News:   XDM1041 Recording Function

XDM1041 running V3.0.1
DMMEasyControl, Version 1.7.0 running on Win10

Local recording and upload of data
- local XDM1041 recording is working
- DMMEasyControl supports upload from XDM1041 to host (slow speed, takes time)
- import of uploaded data into spreadsheet (OpenOffice)
  special characters for °C, °F and Ohm are a challenge
  my solution: open data-file with text editor, copy "strange characters",
               past the "strange characters" as "separation characters" into the import menu of the spreadsheet,
               not elegant ... but working!

Data retention
- power off, 1h later, power on: recorded data still there
- disconnected power cable, disconnected usb-cable, reconnected power (30min later):    RECORDED DATA IS STILL THERE!
  didn't invest more effort to evaluate max. storage time

Big question:
Will OWON also support PT1000 ??? Hope they are reading this thread  ;-)
 

Offline UniSoft

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Re: OWON XDM1041 the unknown multimeter...
« Reply #155 on: January 08, 2022, 04:00:42 am »
Good News:   XDM1041 Recording Function
XDM1041 running V3.0.1
The big question is where to get that firmware?

Data retention
- power off, 1h later, power on: recorded data still there
It is saved inside MCU's flash...
Number of guaranteed program/erase cycles before failure (Endurance): 100 kcycles (according to the datasheet)
And by the way, data and settings can be lost due power failure within erase/write sector.
 

Offline BugCatcher

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Re: OWON XDM1041 the unknown multimeter...
« Reply #156 on: January 08, 2022, 08:27:14 am »
There must be a battery on board. Clock is running without external power supply! The question is the size of the internal SRAM ...
 

Offline theHWcave

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Re: OWON XDM1041 the unknown multimeter...
« Reply #157 on: January 08, 2022, 06:50:36 pm »
Maybe a dumb question but are you sure that the data "saved" by DMMeasycontrol" is actually your locally recorded data? I am asking because DMMeasycontrol had that save-the-recording-as-spreadsheed function before and what it actually did was record new data coming in from the meter online into the spreadsheet. It did not even look at the previously recorded local data.
 

Offline UniSoft

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Re: OWON XDM1041 the unknown multimeter...
« Reply #158 on: January 08, 2022, 08:14:10 pm »
There must be a battery on board. Clock is running without external power supply!
Yes, there is a battery, for clock...
I draw the schematic of the control part, attached...

The question is the size of the internal SRAM ...
If you mean SRAM of MCU, then it is totally 48KB
If you mean storage, then how I said it is stored in FLASH, maximum 1000 points

I am working on reversing firmware...
Funny part, that the firmware is written for STM32F103 MCU (using SPL libraries), but they run it as is on GD32F303
« Last Edit: January 08, 2022, 08:15:59 pm by UniSoft »
 
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Offline BugCatcher

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Re: OWON XDM1041 the unknown multimeter...
« Reply #159 on: January 08, 2022, 09:15:07 pm »
Proof of Recording Function

I tried to make the check waterproof!
- step 1   I disconnected USB from XDM
- step 2   XDM power on
- step 3   Temp -> PT100 -> °C
- step 4   Record -> Manual -> Clear buffer -> Back
- step 5   Auto -> set 20 Points -> Interval 1s
- step 6   soft key Start
                 touched PT100 during measurement (increase/decrease of temperature)
- step 7   checked samples on XDM (increase/decrease of temperature) -> was ok
- step 8   XDM power off, removed PT100 cable
- step 9   reconnected USB
- step 10  XDM power on (running VDC, no PT100 connected!)
- step 11  started DMMEasyControl on PC
- step 12  DMME command Control -> Connect
- step 13  DMME command Record -> Device data export -> entered path/file-name
- step 14  after a few seconds: "Device data export completed!"
- step 15  checked file on PC ... identical with manual observation on XDM -> BINGO!

Stored file:

NO   MODE   VALUE   
1   Period   29.1¡æ
2   Period   29.0¡æ
3   Period   29.3¡æ
4   Period   29.4¡æ
5   Period   29.5¡æ
6   Period   29.6¡æ
7   Period   29.7¡æ
8   Period   29.8¡æ
9   Period   29.8¡æ
10   Period   29.9¡æ
11   Period   29.6¡æ
12   Period   29.0¡æ
13   Period   28.6¡æ
14   Period   28.3¡æ
15   Period   27.8¡æ
16   Period   27.4¡æ
17   Period   27.0¡æ
18   Period   26.8¡æ
19   Period   26.5¡æ
20   Period   26.5¡æ

Other observation:
direct capture with DMME
- you get higher resolution
- you get date/time on top
only problem: formatting of msec is not correct
correct example for time:   19:22:47.779
incorrect example:          19:22:50. 45
-> leading zeros for msec below 100 or below 10 are replaced by "space"
-> trouble with spreadsheet processing

 
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Offline BugCatcher

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Re: OWON XDM1041 the unknown multimeter...
« Reply #160 on: January 09, 2022, 09:11:03 am »
UniSoft

You are right! Data must be in Flash. Leakage of SRAM (deep sleep) is above 100uA.

BTW: Could it be that D1 (in front of battery) is in wrong direction?
 

Offline UniSoft

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Re: OWON XDM1041 the unknown multimeter...
« Reply #161 on: January 09, 2022, 11:34:07 am »
You are right! Data must be in Flash.
I saw it in the firmware code.

BTW: Could it be that D1 (in front of battery) is in wrong direction?
Yes, for sure... I made a mistake.

By the way, Does anyone know what the TFT display is used there.
I did not find anything with such a pinout.
PB2 - D/C (0: Command; 1: Data)
PB10 - CLK
PB1 - Probably RESET

 

Offline BugCatcher

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Re: OWON XDM1041 the unknown multimeter...
« Reply #162 on: January 10, 2022, 07:13:45 pm »
Next Story:   Sampling Rate

The data sheet promises up to 65Hz sampling rate (15.4ms)

First step:

timing only
  I started with the DMMEasyControl tool
  - simple measurement due to time stamps in download,
    1000 samples per run (DCV, 5V fixed, fast mode)

       set sampling rate (ms)     measured sampling rate (ms)
             
         16                        51.1
         18                        51.1
         20                        48.0
         25                        50.6
         30                        51.2
         40                        52.2
         50                        77.9
         100                      110.1
         1000                    1007.8

       -> Dramatic overhead for sampling rates below 1s!
       -> Time stamps are heavily impacted by jitter (a few 10ms)

   Next test is XDM with internal recording

     Due to missing time stamps only total time for 1000 samples (hand stopped)

         15ms   -> 15s
         30ms   -> 30s
        100ms   -> 100s
     
       -> Internal recording of XDM looks ok!


Next step:

What about the quality of the stored measurements?
Used a function generator with a slow triangle wave (below 100mHz)

  downloaded an internal recording of the XDM
  (see "XDM_internal_recording)

       -> looks ok! No Jitter!


Next test is DMME recording with 50ms samples. Big surprise ...
  - samples are repeated!
  - new sample value only after a few 100ms, heavily impacted by jitter!
  (see "DMME_repetition_of_samples")

What happens for 1s sampling?
  - no longer repeated samples
  - impact of jitter still visible
  (see "DMME_jitter_at_1s_sampling)

Potential explanation:
  - rate for new sample values is similar to rate on PC-display (in the range of 2Hz)
  - DMME SW is doing nasty things: delivering correct number of requested samples, update
    of sample value only in sync with display of PC-screen


My conclusion:

     -> for sample rates below 1s you have to use the internal recording!
 

Offline Ringmodulator

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« Last Edit: January 12, 2022, 12:54:12 pm by Ringmodulator »
 
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Offline Johnny B Good

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Re: OWON XDM1041 the unknown multimeter...
« Reply #164 on: January 18, 2022, 04:31:58 pm »
 It appears to be the same breed of "Duck", you know, if it walks like a duck, quacks like a duck...  ::)

 At nearly 200 Euros (and possibly VAT on top - there didn't seem any point checking at that pricing level) for the Voltcraft version, I decided to spend my money on the Banggood offering, namely the OWON XDM1041 USB model for just £96.46 plus  a little extra on shipping and tariff insurance (still just under the 99 quid mark with an estimated delivery by the 29th - a realistic estimate going by recent past experience).

« Last Edit: January 20, 2022, 12:47:14 am by Johnny B Good »
John
 

Offline Ringmodulator

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Re: OWON XDM1041 the unknown multimeter...
« Reply #165 on: January 21, 2022, 08:28:52 pm »
It appears to be the same breed of "Duck", you know, if it walks like a duck, quacks like a duck...  ::)

 At nearly 200 Euros (and possibly VAT on top - there didn't seem any point checking at that pricing level) for the Voltcraft version, I decided to spend my money on the Banggood offering, namely the OWON XDM1041 USB model for just £96.46 plus  a little extra on shipping and tariff insurance (still just under the 99 quid mark with an estimated delivery by the 29th - a realistic estimate going by recent past experience).

It is currently 139,99€ with VAT and shipping included. Add VAT and conversion to € for your Banggood offering, you are about level.
https://www.conrad.de/de/p/voltcraft-vc-655-bt-tisch-multimeter-digital-cat-i-1000-v-cat-ii-600-v-anzeige-counts-55000-2357060.html
 

Offline Johnny B Good

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Re: OWON XDM1041 the unknown multimeter...
« Reply #166 on: January 22, 2022, 03:14:40 am »
 I just checked the currency exchange rates and I reckon I saved close to £20.00 on the deal (Banggood only show VAT inclusive prices, at least to us Brits). What I'd paid, was the equivalent of 119€ in total with no further charges added on.  :-DD
John
 

Offline Johnny B Good

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Re: OWON XDM1041 the unknown multimeter...
« Reply #167 on: January 26, 2022, 05:41:49 pm »
 The XDM1041 I'd ordered from Banggood arrived this morning - three days sooner than Banggood's estimated delivery date. :)

 I haven't tested everything but it seems to be within its specs on DC volts and K-type temperature readings. The standby energy consumption is a gratifyingly low 250mW, peaking to a maximum of 1.5W at a backlight level of 100% dropping to just below 1W at 0% and just a fraction over 1W at the 25% setting.

 I'm monitoring the EFC voltage difference against my GPSDO's internal +2.0000 voltage reference offset which is hovering around the 366.00mV mark (2.36600v) closely matching the mV readings of a Mestek DM91A 9999 counts true RMS dmm I'd been using to see these variations down to a resolution of 0.1mV.

 I could use it to monitor the full EFC voltage (2.3660 volts) direct but I'd end up seeing only the same effective 100uV resolution I was getting with the Mestek DMM and a +2 volt offset.

 The only thing that had initially put me off buying this 4.5 digit bench meter was the lack of any tempco specification, hence my pushing the boat out on an SDM3065X which has impressively low tempco figures.

 In this regard, I don't expect the Owon bench meter will do any better than the Mesteks which, until I had cause to test their temperature stability a few months ago, had seemed remarkably stable in the face of typical changes in room temperature.

 At least the Owon bench meter isn't going to incur regular changes of a pair of AAA cells every 400 hours of run time (I usually disable the auto shut off time out feature built into the Mesteks to avoid losing sight of whatever I'm monitoring for hours long periods).

 I'll give the Owon a more thorough work out later and report the results here in a follow up post.
John
 

Offline Johnny B Good

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Re: OWON XDM1041 the unknown multimeter...
« Reply #168 on: January 28, 2022, 03:27:24 pm »
 I completed my tests and, with the obvious exception of capacitance measurements being extremely slow to obtain results, everything else checks out with remarkably good accuracy against the SDM3065X.

 The only real complaint I have is in regard to the slowness (glacial) in producing capacitance readings. The accuracy of capacitance measurements is on a par with those obtained with other test meters so no complaint there - it's just the very long time required to get the reading that's so intolerable.

 Luckily, I have much better alternative ways to test capacitors, so this is very much far from being a "deal breaker" (as I suspect will (should!) be the case for most other purchasers).
John
 

Offline BugCatcher

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Re: OWON XDM1041 the unknown multimeter...
« Reply #169 on: January 28, 2022, 04:01:07 pm »
Hi John,

happy to hear that you like your new "investment"!
I'm eager to get the following information:
Which FW-version is running in your box?

BugCatcher
 

Offline Johnny B Good

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Re: OWON XDM1041 the unknown multimeter...
« Reply #170 on: January 28, 2022, 09:11:53 pm »
@BugCatcher

V3.1.0
John
 

Offline ass20

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Re: OWON XDM1041 the unknown multimeter...
« Reply #171 on: January 29, 2022, 08:56:24 pm »
for
UniSoft

I check photo(digital board) of xdm2041 and xd1041 and found more identifical parts
see
https://github.com/PetteriAimonen/owon-xdm2041-info
https://github.com/aziemer/Project-Phoenix
and
http://essentialscrap.com/owon_fix/
 

Offline raphaelCoelho

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Re: OWON XDM1041 the unknown multimeter...
« Reply #172 on: February 05, 2022, 12:47:21 am »
Has anyone tried replacing the SMPS with a linear power supply, as commented on in post #51?
« Last Edit: February 05, 2022, 12:49:18 am by raphaelCoelho »
 

Offline kwass

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Re: OWON XDM1041 the unknown multimeter...
« Reply #173 on: February 05, 2022, 04:33:17 am »
Has anyone tried replacing the SMPS with a linear power supply, as commented on in post #51?

Yes, see post #113 in this thread.  My xdm1041 has been running continuously on a lipo cell with wireless charging for the past 8 months or so.  I never turn it off and just pick it up off the changing base when I need to use it off the workbench.  No problems at all, other than the bugs reported above for version 2.xxxxx firmware.
-katie
 

Offline raphaelCoelho

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Re: OWON XDM1041 the unknown multimeter...
« Reply #174 on: February 05, 2022, 06:56:02 pm »
I had already seen your modification, it was very good!
My idea is to put a small transformer and make a regulated power source. In this way try to escape some noise from the original switched power source.
 

Offline Kleinstein

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Re: OWON XDM1041 the unknown multimeter...
« Reply #175 on: February 05, 2022, 07:54:47 pm »
As far As I see it, there is still a ready made DCDC converter to power the analog part. So the SMPS noise may not be the relevant noise source.
The DMM chip set uses a SD-ADC that could have simultaneous 50/60 Hz supression. It still needs the correct clock frequency.  I remember seeing a change in the clock for the XDM2041 that is internally similar.  Has someone checked if the clock is correct for mains hum suppression ?

Edit:
From the pictures it looks like they have the same 4 MHz clock and may thus have a similar poor mains hum suppression problem as here:
https://hackaday.com/2021/07/14/fixing-noisy-measurements-on-an-owon-xdm2041-bench-multimeter/

Changing the clock could still be tricky as this may also effect seriel speed.
« Last Edit: February 05, 2022, 07:58:47 pm by Kleinstein »
 

Offline raphaelCoelho

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Re: OWON XDM1041 the unknown multimeter...
« Reply #176 on: February 06, 2022, 01:41:04 am »
I already read about it...
What it seems is that the problem happens when the main power frequency is 50Hz, on the 60Hz it doesn't.
Anyway, a linear power supply, with transformer, isolated from the network, could not improve the performance of the DMM?
 

Offline Kleinstein

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Re: OWON XDM1041 the unknown multimeter...
« Reply #177 on: February 06, 2022, 09:24:08 am »
An old style 50/60 Hz transformer would have some advantage, as it does not have as much higher frequency common mode bakcground and could get away without a Y cap. It is still not sure if the improvement would be very visible. It could be worth a try - at least for a quick test with an external power supply.  User kwass may be able to tell how much improvement he sees.

The 4 MHz clock is slightly better for 60 Hz than for 50 Hz, but still not really good. So I don't understand why they don't use the correct crystal - that frequency is available (some 50 cents at Mouser) and the 4 MHz one should be only marginal cheaper, if at all.
It looks like the interface to the DMM chip is SPI and thus not sensitive to the clock. So changing the clock should be OK, though it will invalidate the calibration, not just for the frequency measurement. Chances are the BW for AC RMS would also go up a little.
 

Offline Johnny B Good

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Re: OWON XDM1041 the unknown multimeter...
« Reply #178 on: February 06, 2022, 02:23:38 pm »
 From all the teardown videos I've seen and what's been said here, I reckon replacement of the 5v 2.1A smpsu board with a conventional analogue, mains transformer based psu will be a total and utter waste of time and energy (both yours and that of its annual electricity costs).

 As it stands, it only draws a maximum of 1.5W (NOT the claimed 15W which seems to be a typo that lost the decimal point). At a 25% backlight setting, it only draws a tad less than 1W and just a tad over at the 50% setting. Since, unlike a signal generator, all of that input energy lands up heating the bench meter's innards. Indeed, when measuring current, the thermal load sees an increase over and above that basic energy input (another watt when testing a 10A current with (afair) a 0.01 ohm shunt).

 In view of all those downsides, such a psu mod seems doomed to failure in its primary goal of improving the bench meter's noise immunity and performance stability. IOW, I'm strongly suggesting that you don't waste your time (let alone the costs) of replacing the existing smpsu board. :)
« Last Edit: February 06, 2022, 06:57:42 pm by Johnny B Good »
John
 

Offline BugCatcher

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Re: OWON XDM1041 the unknown multimeter...
« Reply #179 on: February 06, 2022, 02:40:47 pm »
I did a few simple experiments:

- recorded the voltage of two alkaline cells (5V fixed, slow mode)
  The Owon DMMEasycontrol App is recording the gain-corrected 24bit ADC-data. This
  is equal to a 6.5 digit resolution. That's resolution, not precision! -> see diagram

  -> No visible noise problem!
        (the spacing of the horizontal lines is 0.1mV ... equals the resolution of the displayed measurement results)

- resistance mode
  two 1m long banana-cables are hanging down "flapping in the breeze", not twisted. Cables are a few cm away from a 230V/50Hz cable
  -> reading: 50MOhm-range "overload"
  connected a 20MOhm resistor at the end of the banana-cables
  -> when I'm sitting still   -> stable reading with the normal 1 unit quantization noise
  -> when I'm moving          -> up to 20..30kOhm variation
                                          -> a few kOhm even if I'm a few meters away

  -> Pure electrostatic effect!   No 50/60Hz interference!


 I don't see any problem!
 
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Offline Kleinstein

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Re: OWON XDM1041 the unknown multimeter...
« Reply #180 on: February 06, 2022, 05:10:52 pm »
The performance looks really good for a 50000 count meter. There is quite a bit extra resolution for the PC, though not clear about the stability and accuracy. The battery may actually show some drift.

The 1 sample per second mode may have good hum suppression even if the integration time is no matching full multiples of 20 ms. To get a good response on the screen, more than 1 SPS (midium speed mode) may be the more relevant case. This would be more sensitive to hum and thus the better mode for a test to hum sensitivity.

The example with the batteries is likely low hum anyway.
The high resistance case would be an example that can be sensitive to hum, but here things can even get nonlinear, especially relatively close to the end of the range.

To judge how good or bad the 50/60 suppresion is would better use a defined identional 50 Hz part. So maybe look at 1 V RMS 50 Hz int the 5 V DC range and record the data to see if there is some beat frequency / residual AC visible.
A SD ADC can have a different filter from the SINC response one gets for simple integration over a fixed time (e.g. dual slope ADC). It still helps to have the frequency about right. Looking at the hum suppression at different frequencies could give an idea about the fitler used and how much a different clock could change.  Loosing the calibration is still a good reason not to change the HW.
 

Offline BugCatcher

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Re: OWON XDM1041 the unknown multimeter...
« Reply #181 on: February 06, 2022, 06:05:43 pm »
Voltage drift is most likely dominated by temperature of battery.
Beside TC and PTxx a third method for temperature measurement ;-)

Additional information regarding high impedance measurement:
before adding the 20MOhm resistor
- switched mode to ACV
- could measure 450mV AC-voltage
-> that's an indication for 50Hz attenuation ... at least sufficient for normal use cases!

The Owon app has pros and cons
pro
- extended resolution
- unlimited recording length
con
- sampling rate heavily impacted by jitter (see the two diagrams)

the XDM internal recording
pro
- more precise sampling rate
- faster sampling
con
- limited number of samples
- only "original resolution"

 

Offline Johnny B Good

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Re: OWON XDM1041 the unknown multimeter...
« Reply #182 on: March 02, 2022, 05:29:12 am »
Yeah, same here. After I saw Misk's post, I send an email to OWON asking about it....  but no response (so far). I'll post if I hear anything

I did an interesting test yesterday using a Peltier element cooling an old heat sink = chunk of aluminium. I had a PT100, the unknown K-type I normally use for the XDM1041 and a known (RS-components) K-type which I use for my BM869S all attached to the same area on that heat sink.  Long story short, it seems as if the XDM1041 was much closer tracking the PT100 when it used the RS-components K-type. That one, RS stock# 409-4920  costs nearly £8 (incl. VAT) and is still only rated as +- 1.5 degC, so I'd imagine the unknown one to be much worse. Side note. To use the RS K-type (or other more professional sensors) you need a K-type adapter. I use the Brymen BKB32 for around £5 from Telonic

 I've been trying, without any success, to obtain K-type to 4mm 19mm spaced banana plug adaptors that do actually use chromel and alumel pins as per a set of four cheap mini K-Type plugs I'd bought to upgrade my collection of K type TCs and was wondering if that BKB32 adaptor would be worth buying.

 I tried to track down information regarding the proper use of chromel/alumel pins in the BKB32 without any success. The only ones I've seen that boast the use of chromel/alumel pins are the rather ubiquitous cheap Chinese ones of which I'd purchased two on the strength of this claim (shown in the attached image below). Unfortunately, they both failed the magnet test rendering this boast a work of fiction. >:( :( :palm:

 I suspect that, since there is no significant temperature differential with battery powered hand held meters, the BKB32 adaptor will very likely not be using chromel/alumel pins so I was wondering if you'd care to verify whether this is the case or not with a magnet test? ;D

 Incidentally, I've just discovered that the HI socket runs 0.5K cooler than the LO socket which seems to be about 1.5K above ambient (the SDM3065X sockets both run within 0.1K of each other, about another 1.5K higher again).

 Neither of these meters can really do any justice to K type thermocouples, the Owon because of its reliance on the meter behaving like a mW powered hand held with hopefully, some sort of calibration offset applied to approximate the difference between its internal temperature and ambient, and the expensive 6 1/2 digit Siglent for its reliance on seemingly very rare chromel/alumen K to banana plug adaptors to ensure that the isothermal reference extends all the way into the socket where it measures the reference temperature at the back of the LO banana jack inside of the meter's significantly warmer interior.

 The Owon, once warmed up, performs almost as well as the Siglent in regard of K type thermocouple sensors. The Siglent has the potential for better accuracy if only a chromel/alumel adapter could be found to maximise the benefit of chromel/alumel mini K-type plug ended thermocouples. :palm:

 If you need a very fast response thermometer with better accuracy, those cheap Chinese TM-902C K type thermometers seem a cost effective way to go regardless of whether you use chrome/alumel mini-K plug ended thermocouples or not.

 The later versions which use a pair of AAA cells, only draw 0,35mA from the battery, a mere 1.5mW, barely enough to raise the temperature by more than a few tens of mK which significantly simplifies the issue of reference end compensation and any need to use chromel/alumel in the mini K type socket or the thermocouple plug. The biggest source of uncertainty will most likely come from the warmth of your hands but you can always get round that issue by wearing winter weather gloves or an oven mitt, :)
« Last Edit: March 02, 2022, 05:34:46 am by Johnny B Good »
John
 

Offline Kleinstein

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Re: OWON XDM1041 the unknown multimeter...
« Reply #183 on: March 02, 2022, 08:27:05 am »
The material in the adapter plugs does not have to be actually Alumel / Chromel like a type K thermoelement. The temperature difference over that adapter part is quite small (e.g. < 1 K) and the temperature range is small. So a different alloy with similar thermal EMF is OK. This also applied to thermo couple extension cables. With type K this may still be lower grade Alumel / Chromel, but for something like the plugs other materials that are easier to machine can be a justified alternative.

If the adapter / plug part is small and thermally isolated the temperature difference over the plug is very small (e.g. < 0.1 K) and the material does not really matter. Littel heat flow also helps with the meter internal temperature gradients.  So a good thermal design can be more important than the "correct" material.

If higher accuracy is needed, the option would be to use an external electronic cold junction compensation. That is a small external circuit to correct for the cold juntion and give the TC voltage as if the cold junction temperature would be 0 C. The meter would than measure voltage and the conversion would be done on the PC side or as a math function.  I have used such small yellow units from Omega, that were powered by a single Li cell and worked quite well together with HP3478 / 3457. For some reason they seem to be no longer available and alternative one are quite expensive.

If multiple channels are needed, an external DIY cold junction box with a sensor could be an alternative. The temperature may be stable enough to only need a single reading.  The scanner cards for DMMs often include a reasonable cold junction sensor, much better than via the normal inputs.

For the SDM1041 the slight problem is that there is no really good low voltage range and the resolution may be limited.  There may still be enough resolution via the PC interface.
 
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Offline piit79

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Re: OWON XDM1041 the unknown multimeter...
« Reply #184 on: April 12, 2022, 01:21:16 pm »
I am working on reversing firmware...

I'm very glad to hear that! Out of curiosity, any progress? The ONE thing I'd like to see fixed/patched somehow is the LONG delay on startup - it's very annoying. I wish I could just short-press the power button to put the meter on :/
 

Offline kwass

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Re: OWON XDM1041 the unknown multimeter...
« Reply #185 on: April 13, 2022, 12:20:58 pm »
The ONE thing I'd like to see fixed/patched somehow is the LONG delay on startup - it's very annoying. I wish I could just short-press the power button to put the meter on :/

I agree.  My solution is to just leave it on all the time.  Mine's been on for almost a year with no ill effects and power consumption is negligible.
-katie
 
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Offline UniSoft

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Re: OWON XDM1041 the unknown multimeter...
« Reply #186 on: April 13, 2022, 06:53:38 pm »
Out of curiosity, any progress?
Nope... I put the project on pause...
I can't find latest firmware (or at least same version as mine), to start testing etc..
Need to extract bootloader first, and to do this I need to write custom code, what will erase current firmware, so I will not be able to restore the same version.
There is only old version posted by @theHWcave.
It actually stops me from further experiments.
Shit OWON no even reply for request of update.

The ONE thing I'd like to see fixed/patched somehow is the LONG delay on startup - it's very annoying. I wish I could just short-press the power button to put the meter on
This can't be changed by firmware...
Power switch is implemented by standalone MCU ATTINY202-SSF...
It is really not hard to write firmware for this MCU. But it cannot be updated via USB/COM.
 

Offline BugCatcher

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Re: OWON XDM1041 the unknown multimeter...
« Reply #187 on: May 15, 2022, 11:15:36 am »
Owon released a new version of the XDM1041!

The new XDM1241 offers internal lithium battery instead of AC power. All other features look identical ...
Banggood is already offering the new device!

http://files.owon.com.cn/probook/OWON_XDM1000_Digital%20Multimeter_USER_MANUAL.pdf

BugCatcher
 
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Offline mapleLC

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Re: OWON XDM1041 the unknown multimeter...
« Reply #188 on: May 16, 2022, 12:52:03 am »
Trying to understand why anyone would want this.
 

Offline Johnny B Good

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Re: OWON XDM1041 the unknown multimeter...
« Reply #189 on: May 16, 2022, 12:53:28 pm »
 Consumer demand?  ::)
John
 

Offline Kleinstein

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Re: OWON XDM1041 the unknown multimeter...
« Reply #190 on: May 16, 2022, 01:09:31 pm »
Battery operation has its advantage: no power cable needed and better isolation / less common mode signal injection to worry about. Even if the possible injection of a common mode signal is not often a problem it helps if you don't have to consider this as a possible source of an unexpected signal.
With the moderate power consumption operation on a rechargible battery and still have a well visible screen is nice.  Keithley / Fluke had early 4.5 digit bench top meters with battery option, so it is not a new invention.
 
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Offline mapleLC

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Re: OWON XDM1041 the unknown multimeter...
« Reply #191 on: May 16, 2022, 02:23:36 pm »
Battery operation has its advantage: no power cable needed and better isolation / less common mode signal injection to worry about. Even if the possible injection of a common mode signal is not often a problem it helps if you don't have to consider this as a possible source of an unexpected signal.
With the moderate power consumption operation on a rechargible battery and still have a well visible screen is nice.  Keithley / Fluke had early 4.5 digit bench top meters with battery option, so it is not a new invention.

Consumer demand?  ::)

I'm one of those consumers that demands a bit more reputation, so this is my old workhorse.  While reputation is on the decline, period specific, reputation still matters.

I wouldn't trade mine for yours.
 
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Offline akisnas

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Re: OWON XDM1041 the unknown multimeter...
« Reply #192 on: May 29, 2022, 07:13:17 am »
Hello everyone, i bought 2 of them a few months before, tested and then storage in original boxes for 2 -3 months before my project started.
Today unpackage and i test them, both of them were dead no powered at all.
I notice the psu is working and 5V is present, have you any idea what is going on?
Is there any member with the same issue?
The rechargeable battery MS621FE measured at 2.6V.
Do you think there is an issue with this battery?
Its really weird...
Thanks for your time.
Best Regards
 

Offline akisnas

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Re: OWON XDM1041 the unknown multimeter...
« Reply #193 on: May 29, 2022, 07:35:56 am »
Problem solved, after 10mins the battery charged and its working again. :)
 

Offline sigxcpu

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Re: OWON XDM1041 the unknown multimeter...
« Reply #194 on: June 23, 2022, 01:02:48 pm »
I will leave this information here, for all others that may be hit by my problem.

I've tried to use the utility & firmware provided here https://github.com/TheHWcave/OWON-XDM1041/tree/main/OWON%20firmware , but the meter didn't exit bootloader/restart - finished with error at "checking new version".
I tried to re-flash lots of times with the same result.

Diode/continuity was broken (showing 0 and beeping continuously), "Utility" menu was also broken. Most likely the "calibration" data was corrupted.
I wrote to Owon but I didn't get any response yet, then I've found this repository https://github.com/PetteriAimonen/owon-xdm2041-info/tree/main/bootloader and a crazy idea was born. What if I write the calibration data from 2041 (thank you PetteriAimonen) to my 1041?
To my surprise, it worked, the meter is fully functional again and, based on few tests I did, accurate enough.

Of course, now it thinks it is a 2041 on version 1.7.2 (the actual version is 2.1.2), but I can live with that.

Attached a picture with the broken "utility" menu.

LE: If somebody would be kind enough to dump the calibration data from their 1041, I would be forever thankful :)
The script to do that is here https://github.com/PetteriAimonen/owon-xdm2041-info/blob/main/bootloader/backup_calibration.py

« Last Edit: June 23, 2022, 02:53:53 pm by sigxcpu »
 

Offline mapleLC

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Re: OWON XDM1041 the unknown multimeter...
« Reply #195 on: June 27, 2022, 06:39:59 am »
I will leave this information here, for all others that may be hit by my problem.

I've tried to use the utility & firmware provided here https://github.com/TheHWcave/OWON-XDM1041/tree/main/OWON%20firmware , but the meter didn't exit bootloader/restart - finished with error at "checking new version".
I tried to re-flash lots of times with the same result.

Diode/continuity was broken (showing 0 and beeping continuously), "Utility" menu was also broken. Most likely the "calibration" data was corrupted.
I wrote to Owon but I didn't get any response yet, then I've found this repository https://github.com/PetteriAimonen/owon-xdm2041-info/tree/main/bootloader and a crazy idea was born. What if I write the calibration data from 2041 (thank you PetteriAimonen) to my 1041?
To my surprise, it worked, the meter is fully functional again and, based on few tests I did, accurate enough.

Of course, now it thinks it is a 2041 on version 1.7.2 (the actual version is 2.1.2), but I can live with that.

Attached a picture with the broken "utility" menu.

LE: If somebody would be kind enough to dump the calibration data from their 1041, I would be forever thankful :)
The script to do that is here https://github.com/PetteriAimonen/owon-xdm2041-info/blob/main/bootloader/backup_calibration.py


Why don't you call Chinese customer service bro?
 

Offline UniSoft

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Re: OWON XDM1041 the unknown multimeter...
« Reply #196 on: June 27, 2022, 03:37:23 pm »
If someone interested, there is a hidden calibration menu (I saw it in code)
UTILITY-MATH-UP-RANGE-DOWN : Enter manual calibration mode (MATH for exit)

DO NOT RUN IT!!! You will lose all calibration values!!!
It requires some additional equipment.
UTILITY-DUAL-UP-RANGE-DOWN : Enter automatic calibration mode (I never run it)
« Last Edit: July 01, 2022, 08:31:52 pm by UniSoft »
 
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Offline msquared

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Re: OWON XDM1041 the unknown multimeter...
« Reply #197 on: June 27, 2022, 07:39:31 pm »
Here' the cal data from my XDM1041. Hope this helps.
 
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Offline Markus2801A

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Re: OWON XDM1041 the unknown multimeter...
« Reply #198 on: June 29, 2022, 12:21:47 pm »
Owon released a new version of the XDM1041!

The new XDM1241 offers internal lithium battery instead of AC power. All other features look identical ...
Banggood is already offering the new device!

http://files.owon.com.cn/probook/OWON_XDM1000_Digital%20Multimeter_USER_MANUAL.pdf

BugCatcher

Has anyone ordered the battery powered XDM 1241 version?
I ordered it a few weeks ago but then got the email that something went wrong with delivery and the package was returned.
Banggood immediately offered a refund, so I don't know should I try it again? is it worth?
Teacher for electrical Engineering @ HTL and Werkmeisterschule :-)
 
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Offline theHWcave

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Re: OWON XDM1041 the unknown multimeter...
« Reply #199 on: July 01, 2022, 08:06:32 am »
If someone interested, there is a hidden calibration menu (I saw it in code)
UTILITY-MATH-UP-RANGE-DOWN : Enter manual calibration mode (DUAL - exit)
UTILITY-DUAL-UP-RANGE-DOWN : Enter automatic calibration mode (I never run it)
That is cool! But in mine I get a DEBUG, KEY, and LCD menu for the first sequence. The KEY and LCD menu are tests for checking key response and LCD, the DEBUG shows two additional values in the normal measurement menus which are called ZERO and COEF. Are these the calibration constants? They appear to be editable. For example in the 5V DC range ZERO is 0000000 and COEF is 0800000 in mine.

The 2nd sequence seems to run a program automatically (no choice, it starts right away) that shows all cal values line by line for all ranges. it is possible that this expects inputs for calibration but it runs quite fast not waiting for inputs. I might possible use the serial port to communicate with a calibrator connected...  Yes, it appears that's what they do in the factory with an automated calibrator attached
DONT RUN IT!  I completely lost calibration on all ranges! !!   :palm:
I do have a dump of my CAL values, now to see if I can load it back ... will report on it  |O
 

Offline theHWcave

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Re: OWON XDM1041 the unknown multimeter...
« Reply #200 on: July 01, 2022, 08:18:21 am »
Ok, using the first DEBUG menu, I managed to get the 5V DC range back. I connected the meter to my DMMCheckPlus reference of 5.0000V and changed the COEF value which did change the reading on the display. Strangely when I hit the RUN/STOP key the COEF jumped to a value which corresponds to exactly 5V. The other ranges are all still hosed. So, manual cal works but I still need to see how to reload the cal dump.
 
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Offline theHWcave

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Re: OWON XDM1041 the unknown multimeter...
« Reply #201 on: July 01, 2022, 01:28:20 pm »
Luckily i had made a recent dump of all CAL data and was able to reload that just now. Everything seems to work as before :phew:

For all you XDM1041 users: Petteri Aimonen's tools to save and load CAL data are here https://github.com/PetteriAimonen/owon-xdm2041-info/tree/main/bootloader    They are for XDM2041 but work just as well for the XDM1041

 
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Offline kwass

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Re: OWON XDM1041 the unknown multimeter...
« Reply #202 on: July 01, 2022, 07:45:48 pm »
I figured out a lot of the calibration process:

Enter calibration as specified about: Utility, Math, Up, Range, Down, Debug (softkey)

Pick the function and range you want to calibrate, each range has it's own calibration values stored.

Toggle between the "zero" and the "coef" number (on the display) using the Range key

Move to the digit you want to change with the Dual key -- it always moves the cursor left to right but will cycle around.

Use the Up and Down arrow keys to increase/decrease the value, it will roll over/under the higher order digit.

You can calibrate the range to any value that you feed into the meter, it need not be the full scale value, 5.0000 volts for example.  If you want to use 5.0000 volts then you can short cut this process and just hit the Run/Stop button.

Exit calibration mode and save you settings at any time by hitting the Math key (not the Dual key as it says above).

I was able to calibrate all ranges for all functions doing this.  However the capacitance ranges are sort of funky, but still work ok.  In all cases I set the "zero" number to all zeros.  I have no idea if that's right or not, but my meter is very accurate now, much better than it was from the factory.  I calibrated against a Fluke 8846A.

-katie
 
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Offline UniSoft

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Re: OWON XDM1041 the unknown multimeter...
« Reply #203 on: July 01, 2022, 09:31:12 pm »
The 2nd sequence seems to run a program automatically...
it is possible that this expects inputs for calibration but it runs quite fast not waiting for inputs.
I guess that. That's why I never run it...

By the way, did you try to contact support to request for the new version of firmware?
I tried many time, but they no even reply  :(

Does anyone know which TFT display they use?
I was looking for it but did not find with such a pinout.
D0...D7 - 8-bit Data
PB10 - CLK (Clock)
PB2 - DC (Data/Command)
PB1 - CS (Chip Select)

« Last Edit: July 08, 2022, 11:03:51 pm by UniSoft »
 

Offline theHWcave

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Re: OWON XDM1041 the unknown multimeter...
« Reply #204 on: July 02, 2022, 04:44:11 pm »
By the way, did you try to contact support to request for the new version of firmware?
I tried many time, but they no even reply  :(
Oh, I was literally pounding continuously on OWON's door for a firmware update. Twice they sent me the same one I already got  |O and published on my Github page (May 2021). Finally, they said asking again is no use because they made a newer version of the meter and new firmware is only compatible with the newer hardware. Thank you, OWON for abandoning your initial customers ...  :--
 
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Offline Markus2801A

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Re: OWON XDM1041 the unknown multimeter...
« Reply #205 on: July 03, 2022, 06:55:08 am »
...they made a newer version of the meter and new firmware is only compatible with the newer hardware...

Very interesting, It would also be nice to know what exactly they mean with "newer version". A new hardware revision? or will there be the Version 2.0 of the XDM 1041, or did they mean the new battery powered XDM 1241?

Teacher for electrical Engineering @ HTL and Werkmeisterschule :-)
 

Offline theHWcave

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Re: OWON XDM1041 the unknown multimeter...
« Reply #206 on: July 03, 2022, 09:45:56 am »
Very interesting, It would also be nice to know what exactly they mean with "newer version". A new hardware revision? or will there be the Version 2.0 of the XDM 1041, or did they mean the new battery powered XDM 1241?

Quote from OWON: 26-Feb-2022: Our engineer said the V3.0 is for different hardware version but all functions are the same to your 2.0 , we don't have any new firmware.

My response: What are the difference between my unit and the newer unit?

Answer from OWON 28-Feb-2022: Using different LCD panel but has the same function
 
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Offline Fungus

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Re: OWON XDM1041 the unknown multimeter...
« Reply #207 on: July 03, 2022, 12:22:15 pm »
Answer from OWON 28-Feb-2022: Using different LCD panel but has the same function

A lot of manufacturers are being forced to change components with all the supply problems going on right now.
 

Offline rsjsouza

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Re: OWON XDM1041 the unknown multimeter...
« Reply #208 on: July 04, 2022, 01:09:37 am »
Not only that, but they reserve the right to change their designs without prior notice... Leaving their customers behind with bugs does not build confidence and taints the track record, but Owon might not give a second thought to this, unfortunately.
Vbe - vídeo blog eletrônico http://videos.vbeletronico.com

Oh, the "whys" of the datasheets... The information is there not to be an axiomatic truth, but instead each speck of data must be slowly inhaled while carefully performing a deep search inside oneself to find the true metaphysical sense...
 

Offline fmolinelli

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Re: OWON XDM1041 the unknown multimeter...
« Reply #209 on: July 16, 2022, 05:20:42 pm »
Hi I ordered OWON XDM1241 from Banggood and I ogt it in 10 days!

The new unit shows FW VER 3.3.1 and its SCPI commands are the same as the one reported by TheHWCave, with some sligth difference and... a bug (CONT and DIODE function selection  are somehow exchanged in meaning; CONF:DIOD put it in DIOD but FUNC? returns CONT; CONF:CONT put it in CONT but FUNC? returns DIOD)

Meanwhile I wrote a config file for TestControllerUA program, so I can get full automated controll of the DMM and gather/store/plot values (only the main function, not the secondary one... I'm tryiing to get it done!)  and I can correlate irt with other bench devices:
https://lygte-info.dk/project/TestControllerIntro%20UK.html

I think it can be easily adapted for XDM1041 ... with some variations due to SCPI implementation!

I'll share it if someone wants to try it!

Many thanks to all EEVBlog contributors, TheHWCave among them, who inspired me!

 
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Offline davebb

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Re: OWON XDM1041 the unknown multimeter...
« Reply #210 on: August 06, 2022, 02:37:18 pm »
I will leave this information here, for all others that may be hit by my problem.

I've tried to use the utility & firmware provided here https://github.com/TheHWcave/OWON-XDM1041/tree/main/OWON%20firmware , but the meter didn't exit bootloader/restart - finished with error at "checking new version".
I tried to re-flash lots of times with the same result.

Diode/continuity was broken (showing 0 and beeping continuously), "Utility" menu was also broken. Most likely the "calibration" data was corrupted.
I wrote to Owon but I didn't get any response yet, then I've found this repository https://github.com/PetteriAimonen/owon-xdm2041-info/tree/main/bootloader and a crazy idea was born. What if I write the calibration data from 2041 (thank you PetteriAimonen) to my 1041?
To my surprise, it worked, the meter is fully functional again and, based on few tests I did, accurate enough.

Of course, now it thinks it is a 2041 on version 1.7.2 (the actual version is 2.1.2), but I can live with that.

Attached a picture with the broken "utility" menu.

LE: If somebody would be kind enough to dump the calibration data from their 1041, I would be forever thankful :)
The script to do that is here https://github.com/PetteriAimonen/owon-xdm2041-info/blob/main/bootloader/backup_calibration.py

Diode/continuity was broken (showing 0 and beeping continuously,  Hi I have been getting this on my meter, i have not updated the firmware, i was thinking it was a relay sticking so i changed them, as it did not do this all of the time, some times i restarted the meter and it still did it, i have a nice fluke so i have not used this meter much or had it plugged in to the mains, yesterday i decided to try and get the AMP scale to Beter calibration to my fluke meter, i used my adjustable load and fist put some more solder on the 10a shunt to see were the reading was going then just used some wick and took a tiny bit of solder of at a time and got it to read within 0.4ma at 1amp and at 10Amp it was reading the same as my fluke,
i have now restarted the meter a good few times and the Diode/continuity problem has not come back, do you think it is the firmware just not booting correctly, would it be wise to try and load a different firmware, My firmware version 1.3.0
Thanks Dave
« Last Edit: August 06, 2022, 02:44:13 pm by davebb »
 

Offline Kleinstein

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Re: OWON XDM1041 the unknown multimeter...
« Reply #211 on: August 06, 2022, 03:23:56 pm »
For the diode / continuity test one could check if there is a test-current flowing. So use a 2nd meter to measure that current (typical some 0.1- 1 mA depending on the meter).
The diodes testing is relatively similar (mainly showing the result different) to the lower ohms modes, so this may also be effected and wirth a test.

I would not expect a relay failure, more like a bad solder joint or PTC. If the ohms modes work and current is flowing it may be a software problem / cal constant set to zero.
 

Offline davebb

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Re: OWON XDM1041 the unknown multimeter...
« Reply #212 on: August 07, 2022, 08:52:23 pm »
Hi if it was a bad PTC would it not do it all of the time ?
anyway i have switched it on and off a lot the last 2 days and i can not get it to do this, at the moment it is all ok, if it goes again i will open it up and try and do some more testing,
Thanks for your Help,
 Dave
 

Offline javican

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Re: OWON XDM1041 the unknown multimeter...
« Reply #213 on: August 22, 2022, 05:07:20 pm »
I just purchased this on Ali and waiting for it to be delivered, I understand the are still a lot of issues so I'm up for the ride!!!
 

Offline bffargo

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Re: OWON XDM1041 the unknown multimeter...
« Reply #214 on: August 30, 2022, 11:38:27 pm »
I just purchased this on Ali and waiting for it to be delivered, I understand the are still a lot of issues so I'm up for the ride!!!

I just did as well, couldn't pass up a $103 super low price + stackable $9 off $90 and $15 off $100; netting it for $79 ish + tax USD. But will see in a month after it arrives.

I am hoping that like the Riden RD6006 power supply, the firmware magicians can make this into something worth much, much more.

I went with the USB instead of DB9, hoping that will be the best for any future interfacing.
 

Offline Alexel

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Re: OWON XDM1041 the unknown multimeter...
« Reply #215 on: September 05, 2022, 09:58:49 pm »
Hi guys.
Today I received my XDM1041. It contained firmware V3.6.0.
I read the calibration table, maybe someone will need it.
Does anyone have an OpenOCD built for Win x64 with C_DEBUGEN disabled? I want to read the full firmware, but so far there is only a computer with windows.
 

Offline UniSoft

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Re: OWON XDM1041 the unknown multimeter...
« Reply #216 on: September 06, 2022, 09:06:41 am »
It contained firmware V3.6.0...
This is probably the hardware version not the firmware...
The firmware just displays the string from the calibration data...
There is no way to determine the OS version. :(

I read the calibration table...
This is not only calibration, as well some configuration, version, serial number, etc...

Does anyone have an OpenOCD built for Win x64 with C_DEBUGEN disabled? I want to read the full firmware
Don't spend time.
This MCU (Cortex-M4) doesn't have that vulnerability.
 

Offline pd9mwo

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Re: OWON XDM1041 the unknown multimeter...
« Reply #217 on: September 06, 2022, 12:56:00 pm »
any ext.ref mod available  ??
thx
 

Offline Alexel

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Re: OWON XDM1041 the unknown multimeter...
« Reply #218 on: September 06, 2022, 02:49:16 pm »
This is probably the hardware version not the firmware...
The firmware just displays the string from the calibration data...
There is no way to determine the OS version. :(
Maybe you're right, but the PCB is marked "YW:2228", while the serial number includes this value - SN:22280222... Maybe the hardware version is included in the serial number?

Don't spend time.
This MCU (Cortex-M4) doesn't have that vulnerability.
Yes, you are right, I did not pay attention to the fact that the chip marking is GD32F303, not GD32F103...
At the same time, ST-Link reads the chip ID as 0x414, which corresponds to F103, and it would be logical to get 0x422 from our chip (This ID for STM32F303xB/C and STM32F358 devices).
 

Offline bffargo

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Re: OWON XDM1041 the unknown multimeter...
« Reply #219 on: September 15, 2022, 01:23:36 am »
Hi guys.
Today I received my XDM1041. It contained firmware V3.6.0.
I read the calibration table, maybe someone will need it.
Does anyone have an OpenOCD built for Win x64 with C_DEBUGEN disabled? I want to read the full firmware, but so far there is only a computer with windows.


I just purchased this on Ali and waiting for it to be delivered, I understand the are still a lot of issues so I'm up for the ride!!!

I just did as well, couldn't pass up a $103 super low price + stackable $9 off $90 and $15 off $100; netting it for $79 ish + tax USD. But will see in a month after it arrives.

I am hoping that like the Riden RD6006 power supply, the firmware magicians can make this into something worth much, much more.

I went with the USB instead of DB9, hoping that will be the best for any future interfacing.

I got mine yesterday. Even newer than Alexel's.  AliExpress seller came through, 17 day shipping to U.S. with all the discounts, no hassle/claims of increased prices/etc.. that other sellers pull. Net cost $79+tax. Very happy.
 

Offline bffargo

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Re: OWON XDM1041 the unknown multimeter...
« Reply #220 on: October 17, 2022, 12:54:42 am »
Did some testing with a 1041 seeing how easy it would be to hack it into a 1241 with only a couple inexpensive parts.

The internal mains AC->DC power supply is labeled as 5VDC@2A. Actual power consumption measured by feeding in 5VDC from bench supply directly into the output pins of the built in one (not removing it from circuit) are as follows with screen brightness at 25%

Standby: 6.15mA
Boot: 160mA
Run (VDC mode): 100mA
I didn't test any other modes

The mains ground pin is connected all the way through on the negative power rail up until it connects to the meter board at which point it is isolated from the front inputs.

It seems a bypass switch (/ hard power off), a USB>LiIon>500ma(to 2A) charge+inverter board and a decent 18650 should be enough to keep it powered for about 10 hours for little cost and lots of room to put it in the back with the mains board removed.
« Last Edit: October 17, 2022, 12:56:21 am by bffargo »
 

Offline piit79

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Re: OWON XDM1041 the unknown multimeter...
« Reply #221 on: November 14, 2022, 09:55:12 pm »
The ONE thing I'd like to see fixed/patched somehow is the LONG delay on startup - it's very annoying. I wish I could just short-press the power button to put the meter on
This can't be changed by firmware...
Power switch is implemented by standalone MCU ATTINY202-SSF...
It is really not hard to write firmware for this MCU. But it cannot be updated via USB/COM.

I wanted to share my solution for this issue. Because the simplest one is obviously to replace a tiny 8-bit MCU with a 32-bit dual-core Arm MCU (RP2040) with 2 MB of flash and program it in (Circuit)Python, right? ;)

Anyway, I achieved my goal - now the startup is on single press while the shutdown has a short (~500 ms) delay.

I wanted to re-program the ATtiny202, but I'd have to make a programmer first and I didn't even find the recommended CH340 serial adapter in my junk box. Might still do that later. The program is literally a few lines of code - not sure if there's anything else happening on the MCU, but the startup is controlled by a single I/O pin (PA1; HIGH - DMM starts slowly / LOW - DMM shuts down immediately). The power button is on PA2. I cut the trace going from the power button to the ATtiny202.

The DMM doesn't start all that much faster as there's still a significant delay somewhere down the line, but I like that I can just press the button and know it will start.
 
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Online mwb1100

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Re: OWON XDM1041 the unknown multimeter...
« Reply #222 on: November 15, 2022, 09:46:16 pm »

Don't spend time.
This MCU (Cortex-M4) doesn't have that vulnerability.
Yes, you are right, I did not pay attention to the fact that the chip marking is GD32F303, not GD32F103...
At the same time, ST-Link reads the chip ID as 0x414, which corresponds to F103, and it would be logical to get 0x422 from our chip (This ID for STM32F303xB/C and STM32F358 devices).

Sorry for responding to an oldish post.  I think the reason for the ID behavior you're seeing is that the GD32F303 is much more like the STM32F103 than the STM32F303.  GD32F303 is basically an STM32F103 clone with a Cortex-M4 instead of a Cortex-M3.  The peripheral devices are clones of the STM32F103 peripherals (same register addresses).
 

Offline ass20

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Re: OWON XDM1041 the unknown multimeter...
« Reply #223 on: November 27, 2022, 09:06:21 am »
hi
About versions

version 2.xx have cpu stm32f103 (cortex m3) or clone

version 3.xx have cpu GD32f303 (cortex m4) 
 

Offline gsmart

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Re: OWON XDM1041 the unknown multimeter...
« Reply #224 on: November 27, 2022, 10:35:25 pm »
Hi dave, i wrote because the same situation as now on my device, different not read at all i have used 4 times now diode is beeping not read volts, and not read resistance at all, fw are 3.1.0 have try to default conf reset but nothing still problem contacted owon with no response and aliexpress buyer protection is 15 day
video attacchment
Thanks for now i hope some one have resolved this issue...
 

Offline John+audio

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Re: OWON XDM1041 the unknown multimeter...
« Reply #225 on: December 10, 2022, 01:20:26 pm »
Farnell in the UK have just added this product to their portfolio of test equipment under the 'MULTICOMP PRO' brand name.

https://uk.farnell.com/multicomp-pro/mp730889/dmm-bench-10a-1kv-50mohm/dp/3972198?MER=TARG-MER-PLP-RECO-STM71233-2

£114.07 plus VAT
« Last Edit: December 10, 2022, 01:22:00 pm by John+audio »
 

Offline bffargo

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Re: OWON XDM1041 the unknown multimeter...
« Reply #226 on: January 02, 2023, 10:25:03 pm »
Did some testing with a 1041 seeing how easy it would be to hack it into a 1241 with only a couple inexpensive parts.

The internal mains AC->DC power supply is labeled as 5VDC@2A. Actual power consumption measured by feeding in 5VDC from bench supply directly into the output pins of the built in one (not removing it from circuit) are as follows with screen brightness at 25%

Standby: 6.15mA
Boot: 160mA
Run (VDC mode): 100mA
I didn't test any other modes

The mains ground pin is connected all the way through on the negative power rail up until it connects to the meter board at which point it is isolated from the front inputs.

It seems a bypass switch (/ hard power off), a USB>LiIon>500ma(to 2A) charge+inverter board and a decent 18650 should be enough to keep it powered for about 10 hours for little cost and lots of room to put it in the back with the mains board removed.

Update: I finally hacked mine, and found out it doesn't need a full 5VDC into the logic board.  It gets by just fine with direct LiIon 3.x volt output and doesn't need to be boost converted back up to 5V as per the original AC>DC converter in it.

I used a tiny micro usb battery charger and a 18650 cell and connected that up to the AC>DC board, then feeding its second output (that is always kept at the voltage of the LiIon charge when on battery alone or ~4.2V when connected to a 5V input.

To my surprise it has been running fine at the lower voltage without issues. I presume it may be dropping to 3.3V or so anyway once on the logic board, but didn't go poking around to verify.

I thought I'd share for anyone else that wants to do a quick hack of the AC powered one into a 18650 powered version. Just need a couple 5 pin male XH2.54 male header pins and a 5 pin female plug with just 2 wires for voltage and you can bypass the feed through to the serial port then and connect up the battery/charge chip.

I didn't take a picture of my mod, but here is a quick drawing.
 
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Offline luma

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Re: OWON XDM1041 the unknown multimeter...
« Reply #227 on: March 16, 2023, 02:54:52 pm »
I've designed a couple 3D printed solutions to mount the XDM1041/XDM1241 for a few use cases.

Here's a model for Gridfinity which lets you mount the meter to a base plate and then stack that into existing gridfinity solutions.  Check the video link below for a fantastic presentation of the Gridfinity system, it's really well thought out and great for electronics workspace organization.

Here's a model for the DDD Wall Control project (this one is my own project).  This system utilizes steel Wall Control pegboards to mount tools etc securely to a wall.  Parts are printed and press-fit like legos to create modular organization solutions for wall mounting.





Gridfinity explanation (entertaining as hell, worth a watch)

« Last Edit: March 16, 2023, 02:56:38 pm by luma »
 
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Offline robdejonge

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Re: OWON XDM1041 the unknown multimeter...
« Reply #228 on: March 27, 2023, 06:29:22 am »
Does the new firmware or new device version (1241) still have the odd mV/V range situation?
 

Offline dreiscal

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Re: OWON XDM1041 the unknown multimeter...
« Reply #229 on: May 18, 2023, 03:09:05 pm »
The 2nd sequence seems to run a program automatically...
it is possible that this expects inputs for calibration but it runs quite fast not waiting for inputs.
I guess that. That's why I never run it...

By the way, did you try to contact support to request for the new version of firmware?
I tried many time, but they no even reply  :(

Does anyone know which TFT display they use?
I was looking for it but did not find with such a pinout.
D0...D7 - 8-bit Data
PB10 - CLK (Clock)
PB2 - DC (Data/Command)
PB1 - CS (Chip Select)


Any luck finding the display partnumber?
Mine got damaged and I cannot find a replacement anywhere.  |O
 

Offline UniSoft

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Re: OWON XDM1041 the unknown multimeter...
« Reply #230 on: May 20, 2023, 09:31:12 pm »
Any luck finding the display partnumber?
Mine got damaged and I cannot find a replacement anywhere.  |O
No luck... :(
 

Offline diogoc

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Re: OWON XDM1041 the unknown multimeter...
« Reply #231 on: June 05, 2023, 10:59:54 pm »
Received my XDM1041 today.
It have version 4.0.0
For now I dont see big issues, all works fine including the software and datalogging export.
I would like only to have the possibility of saving the speed mode.

Regarding the hardware I liked that they used two large ceramic fuses.
There are some small changes in the pcbs but the schematic seems the same.
In the mcu board they changed the LDO to a switching regulator.
 

Offline atat

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Re: OWON XDM1041 the unknown multimeter...
« Reply #232 on: July 18, 2023, 01:33:38 pm »
Downloading recorded data...

one of XDM1041's (useless?) features is the possibility to record up to 1000 data points. The list can't be examined while recording is going on (why???) and every new recording erases the data already collected (in auto mode).

No scpi commands are documented, otherwise known or appear obvious by looking at the firmware that allow the export of the recorded data. As far as I can tell, this is impossible with current firmware.

However, every now an then, someone states that he or she had downloaded the recorded data (presumably using DMMEasyControl) - as opposed to logging a new set on the PC. Can any of these persons step forward and confirm their successful download?

In that case, I'd be very interested in tracing the scpi commands used.
 

Offline diogoc

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Re: OWON XDM1041 the unknown multimeter...
« Reply #233 on: July 18, 2023, 02:07:29 pm »
At least in version 4.0.0 it is possible do download the recorded data using using DMMEasyControl.

This repository have the list of scpi commands:
https://github.com/TheHWcave/OWON-XDM1041/tree/main

However, none is documented for downloading the datalog.

You can try to trace the commands used by DMMEasyControl.
 

Offline vk3em

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Re: OWON XDM1041 the unknown multimeter...
« Reply #234 on: August 19, 2023, 01:56:24 am »
Just bought one from Amazon which had the best price I could find in AU $159 AUD
https://www.amazon.com.au/dp/B0BCFS1JHR
 

Offline oxygen

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Re: OWON XDM1041 the unknown multimeter...
« Reply #235 on: November 10, 2023, 10:15:33 am »
I ordered XDM1241 from aliexpress and came from Czech .
Opened it. There was TWO 18650 2200mAh cells in parallel.
Taped in cell holder, but the tape was not stick good from one side ant cells was almost fallen out. One does not make contact, the other did.
2325 is Year/week code.
Consumption from USB-C without cells installed is about 300mA.
Does anyone measure charging current so far?
Edit: charging current about 1.6A (rough) for both batteries total
Batteries are quite different as capacity. Could be thah on was out of socket, or just cheapest cells.
Purchased 2 Panasonic NCR18650B for replacement
Attached few initial photos.
« Last Edit: November 10, 2023, 02:08:20 pm by oxygen »
 
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Offline EM84

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Re: OWON XDM1041 the unknown multimeter...
« Reply #236 on: November 11, 2023, 08:25:40 pm »
Just sniffed the communication while DMMEasyControl downloads recorded data from an xdm1041. It is a simple (undocumented) SCPI command, it spills out a comma separated list of the table values:

int:record?
 

Offline oxygen

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Re: OWON XDM1041 the unknown multimeter...
« Reply #237 on: November 23, 2023, 05:55:59 pm »
Can measure temp with K thermocouple. Can show current temp, min, max and mV on screen in the same time.
Nice
 

Offline masta_k74

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Re: OWON XDM1041 the unknown multimeter...
« Reply #238 on: November 27, 2023, 06:26:10 am »
@bffargo
You could also simply connect a shottky diode from the USB 5V pin to the output of the power supply unit. Then you could supply the device via the USB port. According to your tests, the few hundred millivolts lost at the shottky should not be a problem. The power consumption is also low enough not to cause any problems when connected to a PC. An ordinary power bank, which I'm sure almost everyone has lying around, would be a good idea.
That's what I'm going to do. It can't hurt to have an optional power supply.
 

Offline ionut22

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Re: OWON XDM1041 the unknown multimeter...
« Reply #239 on: January 09, 2024, 08:03:04 pm »
Hello,

Somebody can help me with calibration file for version V4.1? I pressed auto calibration button from hidden menu and after that i find this topic!

Thankyou!
 

Offline Proxy64

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Re: OWON XDM1041 the unknown multimeter...
« Reply #240 on: February 05, 2024, 01:50:58 pm »
I just got mine, version 4.2
Is there an app running on Macos ?
 


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