Author Topic: how about UT70D multimeter as one of the higher end China made multimeters?  (Read 37064 times)

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Offline slburris

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Anyone tried the UT70D multimeter?  It's a 79,999 count meter with decent specs:

http://www.uni-trend.com/UT70D.html

I think a rebadging of it is the Sper Scientific 840077.  It available from
Amazon for $135.  The UT70D seems to be on Ebay for a similar amount.

Anyone got some PCB pictures of this thing?

Scott
 

Offline armandas

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The closest I could find was this PCB of UT70A model. You might be interested in pictures of UT71 series though: https://www.eevblog.com/forum/index.php?topic=332.msg3421#msg3421
 

Offline Kiriakos-GR

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Anyone tried the UT70D multimeter?  It's a 79,999 count meter with decent specs:
Nop..
But never the less, it looks interesting, and has an 54 megabytes large as "user's  manual".  

Quote
Your Multimeter is an intelligent digital one, a precise
instrument with a resolution of 80,000 counts and up-to
-date automatic computer calibrating function.

High resolution A/D converter and micro-controller data
processing technique is adopted in the Meter, featured
with intelligence, high precision and multi-functions. The
Meter can be widely used in laboratory field service,
domestic and other applications. All the functions and
ranges have full overload protection.

In addition to the conventional measuring functions, it is
equipped with a RS232C standard serial port for easy
connection with computer to realize macro recording and
monitoring and capture of transient dynamic data,
displaying change of waveform during the measurement,
providing data and evidence to engineering technicians
for scientific research. This is also a highly applied digital
multimeter of good performance with display back-light.
« Last Edit: May 14, 2010, 08:43:49 pm by Kiriakos-GR »
 

Offline saturation

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Those trimmer are old tech, e.g. VR7 marked in the photo.  Modern DMM no longer use them.  Its more likely to drift with time, temp, shock and vibration.
Best Wishes,

 Saturation
 

Offline Kiriakos-GR

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Well If some one seeks good points to argue ... ;D
He should read the Users manual.

About True RMS specs , 1000V 40 ~ 400Hz 
Capacitance tester up to 100uF
Display refresh time 5 per second. 
Sleep mode 30 min, buzzer makes five beeps before fall in to sleep .. ( No shit )  :D :D
 

Offline Mechatrommer

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i just ordered a Uni-T UT70B from ebay. I'll take a blind shoot on it for about $70. Lets see if i have a hit :) Thanx guys for info here.
if something can select, how cant it be intelligent? if something is intelligent, how cant it exist?
 

Offline Kiriakos-GR

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i just ordered a Uni-T UT70B from ebay. I'll take a blind shoot on it for about $70. Lets see if i have a hit :) Thanx guys for info here.


Some one is overexcited here ...  ;D

I will only nag about it , about the resolution... other than that looks fine ..
 

Offline Mechatrommer

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i've surveyed from ut60 to ut71 range. IMO, ut6x is quite nice in spec, except they are not auto ranging. auto ranging start from ut70 series, ut71 series is way too expensive for my taste n needs. so it leave me with ut70's. i got most interested at ut70A coz it has great range in 20uA-10A, ut70B got 200uA-10A, but after some 5 minutes meditation, i choose UT70B coz it has R232 connection to PC which i asume data logging capability. hope i'm not mistaken on this. i saw some youtuber post about it (using QBasic to get data out of UT70B).

about resolution? i've been very happy with my SUNWA $20 DMM in term of reading, so i think, with this $70 DMM, i should not be dissapointed by it. if i am/will, then be ready for rant time!
« Last Edit: June 02, 2010, 12:22:51 pm by shafri »
if something can select, how cant it be intelligent? if something is intelligent, how cant it exist?
 

Offline Mechatrommer

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sorry.. correction. the UT70B range is 400uA-10A. NOT 200uA-10A. o well, hope it can read something :P
and also i just noticed... the UT70A is not auto ranging...
UT70C or UT71A could be (a little bit) better than UT70B... with around $20 addition.
« Last Edit: June 02, 2010, 01:55:43 pm by shafri »
if something can select, how cant it be intelligent? if something is intelligent, how cant it exist?
 

Offline Mechatrommer

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i just change the order, add a $20, and ask to replace the model to UT71A, so no more UT70B
if something can select, how cant it be intelligent? if something is intelligent, how cant it exist?
 

Offline cybergibbons

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I find their product naming conventions really hard to follow. It seems that the series name is only really to do with the case and LCD and not very much to do with the features.
 

Offline Mechatrommer

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yup. sometime it is quite overlapping between 70 and 71 series, or even 60's. escpecially in the range. when we go from 60abcd up to 71abcde, the range is going up and down and up again. i think i need all the spec display together to get a better picture (just like parametric table). but generally going from a to d or e version means price going up. the 70d is more expensive than 71a even if the higher "71" number. thats why after making 2nd review, i've change my mind to UT71A due to:

1) greater uA range at low side (200uA on UT71A compared to 400uA on UT70B)
2) USB connection compared to RS232 (not sure whats it for, no review on this online, i hope its for sending data to PC)
3) greater count accuracy, 3999 for 70B, 20000 for 71A
4) with carrying case
5) 71A looks more pro and sexy! oh yeah baby! :)

and all this is just for $20 addition, i think its worth it.
if something can select, how cant it be intelligent? if something is intelligent, how cant it exist?
 

Offline Mechatrommer

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my only concern with this "new technology" DMM is that reading/update speed. i dont understand why more expensive DMM's are very slow at even continuity check where my $20 can do that in split second. similar to other V and A reading too.
if something can select, how cant it be intelligent? if something is intelligent, how cant it exist?
 

Offline slburris

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So I went ahead and picked up a Uni-Trend UT70D multimeter.
I took it apart and it looks a bit different than the earlier UT70 series. 
No pots to adjust for one thing.

I threw up a quick web page with some photos at:

http://random.electroscott.com/ut70d.html

Time will tell how good this meter is compared to my Flukes.

Scott
 

Offline cybergibbons

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2) USB connection compared to RS232 (not sure whats it for, no review on this online, i hope its for sending data to PC)

I'd be very interested to see this as well - there's not much mention of it in the manuals. I can imagine it is just a USB->Serial bridge and works pretty much the same as the older RS232 interface.

I do recall reading somewhere that one of the lower meter (UT61D maybe) output a serial representation of the 7 segment display bars, rather than actual numbers....
 

Offline saturation

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Its inherent in design, consider if they fail to consider this item, what else can they overlook?

FWIW you won't get this issue with an reputable DMM, like a Fluke that you'll have for a lifetime.


my only concern with this "new technology" DMM is that reading/update speed. i dont understand why more expensive DMM's are very slow at even continuity check where my $20 can do that in split second. similar to other V and A reading too.

Best Wishes,

 Saturation
 

alm

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One issue is that you need longer integration times for higher accuracy, but it's technically perfectly feasible to do thousands of readings per second in 3.5 digit mode (recent Agilent DMM's), although not for $100. But if they use the same type of ADC in both models, the more accurate model would need longer integration times.
 

Offline saturation

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Thanks for this work, and good photos.  I agree with your conclusion, use it for low voltage work.

Some comments on its design.

There are a number of solder repairs visible on the back, here's just one zoomed in:



The 9V battery connector has barely any strain relief

glass fuses are a no-no for any CAT level meter, it should be at least HRC or equivalent

That foil shielding appears flimsy; hopefully it stays clear of the PCB to prevent shorting; similar designs are adhesive and stick to back of the casing to reduce risk of shorting





So I went ahead and picked up a Uni-Trend UT70D multimeter.
I took it apart and it looks a bit different than the earlier UT70 series.  
No pots to adjust for one thing.

I threw up a quick web page with some photos at:

http://random.electroscott.com/ut70d.html

Time will tell how good this meter is compared to my Flukes.

Scott

« Last Edit: June 05, 2010, 01:58:31 pm by saturation »
Best Wishes,

 Saturation
 

Offline Kiriakos-GR

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FWIW you won't get this issue with an reputable DMM, like a Fluke that you'll have for a lifetime.



I do not have faith  in this "marketing statement" .
especially by having in mind , the negative and poor behavior of Fluke , to any one who got an used meter.
Not that the ones with sealed ones, will get any better services ..
The Fluke forum is locked ... so no room for complains !!  
I do not see any day/night deferences at the " low end "  Flukes, in comparison with many others branded competitors ..


About baptizing the UNI-T as low voltage , the damn Flukes does not gain any FAME ...

This UNI-T are fabulous ,  even the PCB are ready to accept large HRC fuses ,
but the silly American asses ( Buss and others ) , they charge for them " an fortune " ..

If I was an manufacturer of DMM's, I would use also acceptable "middle cost" FUSE solutions.

Comparing apples with apples ,  the 300$  UNI-T  will have no deference from the FLUKE 87-5 .

  

  
« Last Edit: June 05, 2010, 04:47:20 pm by Kiriakos-GR »
 

Offline neikalo

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I had one of these. I gave it away because I didn't trust it:



(This one was the second with the same problem).

It had a terrible continuity buzzer, poor backlight, and a weired analog bargraph marked 0-10 instead of 0-8 (it's an 80000 count meter). 10 meant 100% of range.

The PC software was pretty basic as well, but it did work.

I paid a lot for it (GBP100). A Fluke replacement was over three times the price but many times better. I never looked back.
 

Offline Kiriakos-GR

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Oh yea this fantastic video ... will blame the UNI-T  for a life time ..  :P

I will have to make my own video , to blame the FLUKE 87-5 about it poor performance as frequency meter ..

I was testing my own tone generator , and I had to amplify the signal with 5W amplifier so to get reliable readings ..
With 0-600mV  input level , it should be hyper sensitive as frequency meter too !!

Or ...
I had to use the output of the tone generator as input on my amplifier ( square signal) , so to have acoustic output,
and another output of my generator ( sine signal ) , as input for the Fluke !!  

Pictures here ..  
https://www.eevblog.com/forum/index.php?topic=629.0

I have 50/50 % , love & hate feelings for the top Fluke , thats why I consider my opinion as less biased.  ;)


    
 

Offline Kiriakos-GR

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and a weired analog bargraph marked 0-10 instead of 0-8 (it's an 80000 count meter). 10 meant 100% of range.

This sounds like a bad joke ...  the analog  bar-graph .. it called as analog because it is ....
Its an second separate meter on a single display ..

Has nothing to do with the main " Digital counts"  meter !!   

 

alm

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Except that the analog bar is based on the same ADC, which has the same digital counts (plus a few extra for auto zero). It's not like the resolution is limited by the LCD display. If the bar graph indicates 9, that would mean 90% of 80V = 72V. Are you seriously suggesting this is intuitive?
 

Offline Kiriakos-GR

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For any such details , just read the manual ..

http://www.uni-trend.com/manual2/UT70DEng%20ManualLVD.pdf

Analog  = analog  

scale 0-10  =  0-10 volts  0-1000 volts  etc etc  

Metrix (France ) had build even an DMM with analog needle and digital LCD in one package.    

Here is the proof , that the UNI-T does have 0-1000 scale !!  :P
Page 17 ...
« Last Edit: June 05, 2010, 10:18:30 pm by Kiriakos-GR »
 

alm

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For any such details , just read the manual ..
I did, and it took ages to download (slow site):
Quote from: UT70D manual, page 34
For example, when 80V range is selected, the full-range value of the analog display is 80V, and as the full range is uniformly divided into 10 grades, each grade denotes 8V; If the input is 40V, the high-lighted bar-shape will be at the position indicated by the number 5.
5 = 40V? This is completely stupid, they should have just used the scale between 0 and 8 instead of requiring the user to memorize 8/10th fractions.

Analog  = analog  

scale 0-10  =  0-10 volts  0-1000 volts  etc etc  

Metrix (France ) had build even an DMM with analog needle and digital LCD in one package.    
I know it's technically possible to combine an analog and digital meter (Fluke did this in a wideband RMS meter, ironically it also indicated 0 to 100%), but that's a lot more expensive than just sampling from the same ADC in low-resolution high-speed mode, which is what almost any DMM does.

Here is the proof , that the UNI-T does have 0-1000 scale !!  :P
Congratulations, the bar graph scale does work correctly at one range setting! I'm impressed.
 


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