Result of nonlinearity and dc offset combined? Bruce
> > On 19 January 2018 at 00:57 "David C. Partridge" > <[email protected]> wrote: > > 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.
