If there are any other members of the group with a 6048, I'd be grateful if you would attempt to recreate the scenario I describe to determine if this is just my meter or impacts other 6048 users.
Thanks Dave -----Original Message----- From: volt-nuts [mailto:[email protected]] On Behalf Of David C. Partridge Sent: 18 January 2018 11:57 To: 'Discussion of precise voltage measurement' Subject: [volt-nuts] Prema 6048 zero offset problems Starting with a warmed up Prema 6048, if I power it off and then on, select 20V DC range, 4 second integration and connect to the 10V output of a Fluke 732A, I get a reading of: +10.000047 If I reverse the polarity of the cables and allow the reading to settle down for a minute, I get a reading of: -10.000006 If I short the inputs of the meter, I get a reading of: +0.000105 which is different from the +0.000020 which I would have expected from the readings of the 732A output. Proceeding on the assumption that the meter has stored a zero offset of -105uV I then press the ZERO button to null out the offset and then reconnect the 732A in normal polarity I get an incorrect reading of: +10.000153 This is not what I would expect to see - I would expect to see a reading of +10.000047 - 0.000105 = +09.999942 This calculation I then reverse the inputs and get a reading of: -10.000113 which is close to the expected reading of -10.000006 - 0.000105 = -10.000111 I have mailed Prema about this problem, and will let you know what they have to say. Cheers David Partridge _______________________________________________ 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.
