Products > Test Equipment
UT61E drift and recalibration
Rick Law:
UT61E owners – What is your experience with the UT61E's first year drift?
My UT61E is near 1 year old now. I am curious as to what the typical drift may be. I am considering getting the DMM Check Plus, but want to compare notes with fellow owners.
I also noted from another post on this forum on “replace dc calibration potentiometer on ut61e” that if/when calibrating the UT61E using VR1, even closing the case back will cause a few digit difference, and that the UT61E is rather temperature sensitive.
That post was about replacing VR1 and not about (re)calibrating the UT61E in general. What are your thoughts with recalibrating using DMM Check+? Worth the trouble?
Thanks
Rick
Wytnucls:
Here is a drift comparison between my UT71B/D and 61E, which was done about 6 months ago. The meters all have the original factory calibration. The 71D was used as a reference. You will notice that the 71s are very close to each other, while the 61E had drifted quite a bit.
Lightages:
The drift problem is probably why I never replaced my blown UT61E. I liked it at first but I found I had to keep tweaking it and that really isn't the way a good meter should behave.
Wytnucls:
Just did another drift comparison between meters. The UT61E seems to be getting worse, whereas the UT71s are pretty much together. The 71s have 5ppm/c precision film 0.02% resistors, hence less drift I assume.
The table lists the LSD differences, with the 71D as the standard. All readings were very steady, down to the last digit, with a linear power supply from 2 to 14V DC.
Rick Law:
--- Quote from: Wytnucls on November 25, 2013, 04:32:27 am ---Just did another drift comparison between meters. The UT61E seems to be getting worse, whereas the UT71s are pretty much together. The 71s have 5ppm/c precision film 0.02% resistors, hence less drift I assume.
The table lists the LSD differences, with the 71D as the standard. All readings were very steady, down to the last digit, with a linear power supply from 2 to 14V DC.
--- End quote ---
Thanks for the info! From your post, it looks like I am looking at about 10 count drift. My requirement (with accuracy) is not high. 10 count drift doesn't please me, but it is (unhappily) acceptable to me.
--- Quote from: Lightages on November 23, 2013, 03:39:07 am ---The drift problem is probably why I never replaced my blown UT61E. I liked it at first but I found I had to keep tweaking it and that really isn't the way a good meter should behave.
--- End quote ---
While I am curious about the drift, at the same time, I feel a little silly spending $62 (DMM Check Plus) to check on my $60 DMM. You "tweak it" and get it back in line. Are you tweaking VR1 alone?
Thanks, both for the info. You are very helpful.
Let me rephrase the question this way:
The DMM Check Plus gives me a +5v +- 0.1% to 5 digits. If I can re-calibrate VR1 (alone) with the 5V reference, I am hoping to bring it back to say reduce the error by 1/2 (say from 10 digit off to 5 digit off). Am I dreaming or is that realistic?
I still feel a little silly spending $62 to adjust a $60 DMM, but that would be at least more than merely satisfying my curiosity...
Thanks again, both Mr Wytnucls and Mr Lightages. I appreciate your help.
Rick
Navigation
[0] Message Index
[#] Next page
Go to full version