-----Original Message----- From: Dr. David Kirkby <[email protected]> To: gandalfg8 <[email protected]>; Discussion of precise voltage measurement <[email protected]> Sent: Sun, 29 Apr 2018 22:18 Subject: Re: [volt-nuts] Cropico DO4A Digital Ohmmeter
I see this is a low-resistance (10 u ohm resolution) ohmmeter. Have you any idea how you are going to check the calibration? I just bought a Simpson 444, which has 1 u ohm resolution. I have not got it yet, but are wondering how I am going to check the calibration. 0.005% resistors are available from Farnell in a fairly limited number of values, but certainty not in the range of values needed for a milli/micro ohm meter. Dave --------------------- Whoops, whilst checking the calibration is one thing, actual self calibration on the DO4A is perhaps not looking quite so straightforward, it's an automated calibration process that requires six set resistor values of 4mohm, 40 mohm, etc up to 4Kohm, and a quick check online doesn't show high tolerance versions of these values exactly falling out of the woodwork! Nigel, GM8PZR _______________________________________________ volt-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there. _______________________________________________ volt-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
