Uni-Trend 2013 Catalogue

[rr100]

This one might do it for you: DM620, at $130.00

That's in fact very good, at least spec-wise vs price !
Pity the shipping is $96.11-$147.47...

Speaking of UT ... why don't they have logging in things like UT81B (at least I can't find it in the specs)?

[T4P]

10 screens and setups but not DMM datalogging 

[Wytnucls]

There is also an interesting Micro-Ohm meter UT620A:

0.25%+25 digits?  very sad even for an inexpensive meter. That is 0.5% of reading errpr for a 0.1 Ohm and 25.25% of reading error at 0.001 Ohm.

Is there really a requirement to measure down to 0.001 Ohm in the field? Anything more precise would possibly make it too bulky and expensive. I suspect this instrument will be used mostly to measure cable lengths on an industrial site.

[robrenz]

Is there really a requirement to measure down to 0.001 Ohm in the field? Anything more precise would possibly make it too bulky and expensive. I suspect this instrument will be used mostly to measure cable lengths on an industrial site.

#10 solid wire is roughly 1 Ohm per 1000 feet that would be .001 ohm per foot.
#4 solid wire is roughly 0.25 Ohm per 1000 feet that would be .00025 ohm per foot.
Contact resistance measurement can easily be only a few hundred µohm.

If this thing is only 100 to 200 dollars then I agree I am being to critical. 

[grenert]

Is there really a requirement to measure down to 0.001 Ohm in the field? Anything more precise would possibly make it too bulky and expensive. I suspect this instrument will be used mostly to measure cable lengths on an industrial site.

Regardless of whether that is a requirement in the field, I think that if they claim it can do something, then it should really be able to do it.  You'd probably do better putting together one of these:
http://www.aeroelectric.com/articles/LowOhmsAdapter_3.pdf

[Monkeh]

Is there really a requirement to measure down to 0.001 Ohm in the field? Anything more precise would possibly make it too bulky and expensive. I suspect this instrument will be used mostly to measure cable lengths on an industrial site.

#10 solid wire is roughly 1 Ohm per 1000 feet that would be .001 ohm per foot.
#4 solid wire is roughly 0.25 Ohm per 1000 feet that would be .00025 ohm per foot.
Contact resistance measurement can easily be only a few hundred µohm.

If this thing is only 100 to 200 dollars then I agree I am being to critical. 

Who works in feet anyway?

[Wytnucls]

I just want to let people know, that I received an e-mail from UNI-T international sales office in Shanghai, to let me know that my UT71B multimeter has been repaired and is ready for collection.
It has been 2 weeks since I dropped it off at the company's Shanghai's office. Pretty good turn-around, I think, considering it had to go back to the factory in Dongguan City.
I'll let you know later if it was repaired properly. (Peak Hold was indicating half the real value)

If you buy your Uni-T meter from WELC in Hong Kong, you get a local three year warranty and they have a repair facility in Sham Shui Po.

[grenert]

Please take some pictures if you decide to open it up when you get it back.  It would be interesting to see if it was really repaired and if so, how good a job they did.  In the United States, I'm sure they'd take the meter back and destroy it, or sell to some company that re-sells returned merchandise.  It's just not worth paying someone here to fix anything any more unless it's really expensive (hundreds of $$ or more) or irreplaceable.  We have become a throw-away society 

[Mechatrommer]

well they do make one it's called the UT71A but that is garbage

since you mentioned that. do/did you own it? or ever have used it?

[Wytnucls]

Here is a report back on the Uni-T repair of my 71B:
The meter was returned with a few scuff marks on the plastic LCD window, but these were easily polished off with a bit of toothpaste and some elbow grease.
I was able to test the meter correct readings of Peak Hold, while in the UNI-T office, with one of their own function generators.
I was informed that the meter was also recalibrated at the factory.
I opened the meter and noticed that the precision resistors metal shield had been taken off and then resoldered for better access to the PCB, where two previously unpopulated footprints where now filled with new capacitors.
I notice that on most REV4 boards I have seen online, these unmarked footprints are left unpopulated. On the REV6 boards, these footprints don't even exist anymore.
So anyway, I'm very happy with the repair, my 1000V HRC fuses and battery connector modifications were left untouched and the meter now reads amps correctly, as before, I had thrown it out of calibration, with the addition of the big HRC fuse.

Here are the before and after pictures:
(Repair on the bottom left of the last picture)

[T4P]

well they do make one it's called the UT71A but that is garbage

since you mentioned that. do/did you own it? or ever have used it?

I borrowed one and then returned in a week, it's the UT71E specifically

[SeanB]

Those between R38 and C36. Looks like they are PCB trim capacitors, where you connect sections to increase the capacitance of the unit.

[Mechatrommer]

Here are the before and after pictures:

thanks for the image. they also turned the blue trimpot. it was at 5 o'clock, now its either 2 or 8 o'clock.

[Wytnucls]

Well spotted. They did calibrate the unit. The blue trimpot (VR2) is used for DCV calibration. It now reads virtually the same as my 71D.


  61E       71D      71B
4.006     4.006      4.004
6.010     6.009      6.008
8.000     8.000      7.999
10.002   10.002   10.002
12.007   12.006   12.007
14.003   14.003   14.003

[jabramo]

Is there a typo for the UT612 LCR meter? It beats the UT611 in every respect except for inductance... The 611 can go as low as 600uH but the lowest the 612 is 20mH do they mean uH? Just doesn't seem consistent with the rest of the data sheet.

Anyways any hint at pricing for UT139 meters?

[Wytnucls]

I haven't been able to play with any of them yet. The 611 will only be released in 2013, I was told.
The LCR meters are quite different from each other. The 612 should still be the better meter with its higher 20,000 count and USB data logging, but is let down by a screen which is difficult to read, I believe.
The 611 compensates by having internal logging (1000 readings) and what looks like a much better screen, albeit without a backlight!
Typos are possible and everything in the catalogue should be taken with a pinch of salt.

Again, the UT139 will only be released in 2013, but I would be surprised if it costs more than the 61E.

[T4P]

Frankly the UT139C it looks like a rehash of the UT61D, it does! But it's got low-pass filtering ... But it too seem to have a ability to read a clamp meter's output, not that they have anything right now that will support the function(probably)
Checked the clamp meters yet?

[StubbornGreek]

  You'd probably do better putting together one of these:
http://www.aeroelectric.com/articles/LowOhmsAdapter_3.pdf

I think I like it - would be nice when away from a bench meter... Have you used one of these? If so, your thoughts?

Also, any specs on that Arb Gen or Scope yet?

[jarvis]

Is there a typo for the UT612 LCR meter? It beats the UT611 in every respect except for inductance... The 611 can go as low as 600uH but the lowest the 612 is 20mH do they mean uH? Just doesn't seem consistent with the rest of the data sheet.

Anyways any hint at pricing for UT139 meters?

Actually, UT612 should be 20uH min. range for inductance mode.

[Wytnucls]

Here are the three new clamp meters, of which two are compatible with the new UT139C mutimeter:
 

[grenert]

  You'd probably do better putting together one of these:
http://www.aeroelectric.com/articles/LowOhmsAdapter_3.pdf

I think I like it - would be nice when away from a bench meter... Have you used one of these? If so, your thoughts?

Yes, I've built and used one of those adapters.  To avoid too much off-topic stuff in this thread, I will start a new thread for it.  In short, it is a great little design, easy to make work well.

[jarvis]

Here are the three new clamp meters, of which two are compatible with the new UT139C mutimeter:

DO you have the specification of UT139 ?

[Wytnucls]

Specs on post #8

[jarvis]

Specs on post #8

Thanks for your post.

45 - 400Hz  or 1kHz bandwidth for True RMS meter ? Hmm....

[Wytnucls]

Yes, it is rather lame. More evidence that these meters will be priced quite low.
If you need True RMS for high frequency signals, the only choice amongst UNI-T meters is either the 61E which goes up to 10kHz, or even better, the 71 series, going up to 100kHz.