Author Topic: Calibration of UT81B  (Read 4506 times)

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Offline Joules

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Calibration of UT81B
« on: April 15, 2013, 05:12:45 pm »
Hi guys,
           I'm new here, but happened on a useful feature for anyone with a UT81B scope meter.  If you power the device up and hold the HOLD button down it takes you to a calibrate screen for the scope.

Press F1 to enter calibration, or F4 to Quit

You will then be asked for a password, 5 seconds of hacking solved it.  Press F4, F3, F2, F1

Next it will ask you to short the leads and set the base level for the voltage ranges, press F4

Once it has cycled through that, you need to have a precise 600mV source ready, I used my PSU and a voltage divider to get it spot on, and left my reference meter in circuit.  Press F4

This will cycle to the next 1.5v reference and finally the 3v reference.   F1 at the end to save the new calibration and your done.

I gained a further 15mV accuracy doing this on my meter thats a few years old.

               Joules   :-DMM

« Last Edit: April 15, 2013, 05:14:30 pm by Joules »
 

Offline Rick Law

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Re: Calibration of UT81B
« Reply #1 on: April 17, 2013, 12:43:02 am »
Thanks for sharing!

How is the UNI-T 81B serving you?  I am trying to talk myself into needing one.
 

Offline Joules

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Re: Calibration of UT81B
« Reply #2 on: April 17, 2013, 07:23:50 am »
Rick,
      I've actually been very pleased with mine.  It's not my only meter and I use it mostly with a netbook for data logging (up to a week logging) battery charge discharge cycles and charge controllers for solar installs, so pretty much low frequency stuff.  It is very handy for looking at mains voltage stuff, checking my inverters and generators are producing clean sine(ish) waves.   The fact it is cheap and portable over my dual trace analog Hameg, means it is a first fix scope for quick diag's before more in depth work.  Its also my only storage scope for now.

If I was buying again, I would also consider the new UNI-T 25Mhz scope once I learn if it is optically isolated for data logging.

A friend picked my meter up in a Chinese market about 4 yrs ago.  Use it several times a week if its not tied up logging so for me its been reliable.  Can't really ask more of it than that.
 

Offline SantaClaw

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Re: Calibration of UT81B
« Reply #3 on: December 17, 2015, 11:42:16 pm »
If you power the device up and hold the HOLD button down it takes you to a calibrate screen for the scope.

Press F1 to enter calibration, or F4 to Quit


FYI, I have the UT81C and I had to hold down the hold button as I switched modes to get the cal screen. Thanx to Joules BTW :)
 


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