Author Topic: Uni-T UT181A pictures  (Read 49082 times)

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Online joeqsmith

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Re: Uni-T UT181A pictures
« Reply #50 on: December 17, 2016, 06:31:07 pm »
Thanks.  I learned a lot about the different brands by having it.   
How electrically robust is your meter?? https://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg
 

Offline cidak

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Re: Uni-T UT181A pictures
« Reply #51 on: December 18, 2016, 10:08:42 pm »
Just for informations: today Amazon.it discount this meter for 215.19€ shipping included

Comprato!
E mi arriva domani.
Grazie. :-+
 
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Offline 3nigm4

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Re: Uni-T UT181A pictures
« Reply #52 on: December 19, 2016, 09:04:01 am »
Comprato!
E mi arriva domani.
Grazie. :-+

Di nulla ;D
Al black friday lo vendevano a 199€... ci stavo per fare un pensierino anche io, ma poi ho preso l'UT71D, più che sufficiente per lo sporadico uso mio
 
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Offline .rpv

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Re: Uni-T UT181A pictures
« Reply #53 on: December 30, 2016, 10:24:58 pm »
Hi guys, I bought this meter on ebay for 220 usd (270 regular price but with the ebay's black friday promo: 20% discount up to 50usd) and as the seller didn't have it on stock so he offer me free dhl shipping if I'll wait a bit more than 2 weeks, arrived almost a month since I paid.

The meter it's awesome, I bought it pretty much for what I saw on Joe Smith's review.

Yet I've a issue, out of the box I tried continuity (only with the tips) and it work fast, not as fast as the 61e but acceptable, then I remove the probe caps and tried again and it was sooooooooooo slow, I cleaned all the metal on the probe ends and worked as when I tested only the tips, but then I tested resistance shorting the leads and I wasn't able to get a steady reading, the thing just jump from 0.00 to 0.30 \$\Omega\$ very randomly so I cleaned again the probes even the meter inputs (because it happen with other probes too) with a metal brush, acetone (not pure, the one that is used to remove nails paint) and alcohol (isopropyl) and now seems to work properly  :)
« Last Edit: December 30, 2016, 10:32:06 pm by .rpv »
 

Online joeqsmith

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Re: Uni-T UT181A pictures
« Reply #54 on: December 31, 2016, 03:23:46 am »
I hope you watched at least the last few minutes of that part 1 and understand that it's pretty much like every other UNI-T I have looked at with a weak front end design.   

I went to look at my spreadsheet and I never ran checked the continuity on the UT61E.   At 4Hz the 181A is not a great performer but better than a lot of the ones I tested. Certainly able to detect a short fast enough at 1.5ms. 

Hope you enjoy it.
How electrically robust is your meter?? https://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg
 

Offline .rpv

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Re: Uni-T UT181A pictures
« Reply #55 on: December 31, 2016, 10:00:23 pm »
I hope you watched at least the last few minutes of that part 1 and understand that it's pretty much like every other UNI-T I have looked at with a weak front end design.   

I went to look at my spreadsheet and I never ran checked the continuity on the UT61E.   At 4Hz the 181A is not a great performer but better than a lot of the ones I tested. Certainly able to detect a short fast enough at 1.5ms. 

Hope you enjoy it.

Yes, I saw the 2 parts, the 61e it's same or even a bit worst but so far so good  8)
I'll order some of those buck converters after the chinese new year  :P , BTW did you find why got burned?

And yes, I enjoy a lot of your reviews, somehow I got addicted to multimeter reviews, I really like your approach about comparing at least 3 meters, your comments about the tests and creating 2 episodes where the torture test it's apart, but being honest I really don't know where you can find those kv peaks on real life.

Very nice work and understandable even for a hobbyist  :-+
 

Online joeqsmith

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How electrically robust is your meter?? https://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg
 

Offline fs92

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Re: Uni-T UT181A pictures
« Reply #57 on: November 12, 2019, 07:49:29 pm »
Hey there, though there's been no post for some time it's a very informative thread for me.

I got the UT181A in used condition from ebay recently, but it seems to have a problem with measuring low resistances.

Can you do a reference measurement for me, so i know if mine is defective. If i measure a resistor rated 15 Ohms in Autorange mode, the multimeter shows OL (to low resistance / continuity). When i switch to Kiloohms manually, it measures correct: 0,0144 Ohms. But not in Ohms range, even in manual range.

Could you do a measurement with something like 10, 15, ... Ohms?
Thank you very much in advance :) :) :)
 

Offline bartwas78

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Re: Uni-T UT181A pictures
« Reply #58 on: November 15, 2020, 02:02:24 pm »
Hello everybody. Just got my UT181A yesterday and I thought I will share my small mod for long time logging. I have fitted 2mm banana posts in the back, they will be directly connected to battery for lipo charging. Still waiting for JST XH connectors to make harness inside the meter. Posts will be hot glue gunned (black color) to make it a bit waterproof and the area will be covered with aluminium tape to restore shielding.
Hope someone will find this useful and more esthetic than previous battery mod.
 

Online joeqsmith

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Re: Uni-T UT181A pictures
« Reply #59 on: November 15, 2020, 04:00:15 pm »
Hope someone will find this useful and more esthetic than previous battery mod.

You don't provide enough information to suggest how you plan to keep the unit charged and provide isolation.   If these wires are shorted, what happens to the internal cell?  What happens if you overcharge the cell?   Your mod would interfere with the BLE interface, prevents laying the meter flat, if there was a warranty I suspect it voids it.     

I just finished charging my 181A.  It takes a good 12 hours, during which the meter can't be used.  It has roughly a 40 hour up time.  I'm not sure on the BLE battery life.  I wonder if someone would ever offer a high capacity battery holder that bolts into the back cover, similar to the Fluke 189. 
How electrically robust is your meter?? https://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg
 

Offline bartwas78

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Re: Uni-T UT181A pictures
« Reply #60 on: November 15, 2020, 04:36:37 pm »
Well...
Isolation, was thinking to use two shottky diodes and set up charging voltage higher than 8.4V (+2xVfd) and put label in the back.
The terminals have no metal parts exposed, they are deep inside the plastic so there is not much risk shorting it on flat surface anyway. With diode isolation it will be perfectly safe to short it.
Regarding charging I believe most of us have some experience charging lithium batteries and I believe we all know what we are doing.
if someone wants could easily modify battery and attach cheap 2s BMS from china to protect the cells from any kind of accidents.
About meter in flat position, you could get 2mm banana connectors and they are really tiny so meter could be still used flat.
Of course warranty on mine is already gone, but there are ways to have it fixed under warranty anyway.
I believe i have found 3600mah lipo battery which will fit in there, just ordered it. Look for battery for Wltoys 12428, looks like it has the right size and with bit of modification will be working fine with fast charging capability (2hrs easily). When it comes I am planning to fit it with proper BMS and get 60hrs run time.
« Last Edit: November 15, 2020, 05:11:48 pm by bartwas78 »
 

Online joeqsmith

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Re: Uni-T UT181A pictures
« Reply #61 on: November 15, 2020, 06:58:19 pm »
After seeing the mod, I was thinking more along the lines of the rest of the mess that goes with it shorting out.   Assuming your two diode are in series with each battery you are cutting into the run time. 

I don't understand why ruin the meter just to gain 20 hours?  I never understood that other person as well who really made a mess of theirs.  Theirs should have won a special award.    :-DD   

If the goal was to increase the run time, why not forget the charging, pull the internal pack and go with something much larger?   Get it into the several hundred hours?   
How electrically robust is your meter?? https://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg
 

Offline The Soulman

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Re: Uni-T UT181A pictures
« Reply #62 on: November 15, 2020, 07:11:07 pm »
How about isolation between com post and external charger connection?!?  :palm:
 

Online joeqsmith

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Re: Uni-T UT181A pictures
« Reply #63 on: November 15, 2020, 07:19:45 pm »
Are you thinking they are charging the battery and using the meter with the charger running off the mains?   Scary stuff.... 
How electrically robust is your meter?? https://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg
 

Offline The Soulman

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Re: Uni-T UT181A pictures
« Reply #64 on: November 15, 2020, 07:33:57 pm »
Are you thinking they are charging the battery and using the meter with the charger running off the mains?   Scary stuff....

Or probing a mains socket with the meter in your sweaty hands..
 

Offline bartwas78

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Re: Uni-T UT181A pictures
« Reply #65 on: November 15, 2020, 07:43:06 pm »
After seeing the mod, I was thinking more along the lines of the rest of the mess that goes with it shorting out.   Assuming your two diode are in series with each battery you are cutting into the run time. 

I don't understand why ruin the meter just to gain 20 hours?  I never understood that other person as well who really made a mess of theirs.  Theirs should have won a special award.    :-DD   

If the goal was to increase the run time, why not forget the charging, pull the internal pack and go with something much larger?   Get it into the several hundred hours?

Diodes will only separate battery from connection terminals, in the path between meter and battery is direct connection as before so no run time loss.

I am gaining only 20hrs on one runtime and if i need to use it for longer i can always charge while logging and extend the time. Of course I will have to watch not to short the circuits. If i will be charging from another battery pack, then there is no risk.

Meter still looks decent and addition in my case will be only two terminals and two diodes. Simple and beautiful and it will be working.

So far not seen better solution to the short runtime problem
« Last Edit: November 15, 2020, 07:51:10 pm by bartwas78 »
 


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