no, this is work and it is not that accurate. that is just our best guess (about 1 ppm) of an old fluke 732B. We compare with our other 732Bs. Any available 3458As are monitoring the Flukes. Each hour a program picks up the Mean Max Min standard deviation from each meter average them together and plot the Mean for all the meters... Some times I have had 10 meters but sales have been up so I am down to 1 this week. I have about 5000 hours of data. Most 3458As come in within a few ppm of this standard. We send 3458As out to Agilent for repair and calibration then check our lab standards. Old standards and meters seem to be a lot more stable than new ones.
On Wed, Aug 14, 2013 at 9:45 PM, Demian Martin <demian...@yahoo.com> wrote: > Do you really have a .01 PPM voltage reference? A personal JJ? That's > taking > this hobby to a new level. > > > > > Daniel, > > They are made like that... Problem is with drift. > > When you cal a 3458A the first step is to short the inputs and wait for > the > > thermals to die. Then you do a Cal 0 and the incitement stores all the 0 > > offsets for that set of terminals. they you switch to the other set and > do > it > > again. > > Next step is apply 10 votes to the terminals or in my case it is > 9.9999411 > and > > enter cal 9.9999411 front and back set of terminals. remove the voltage > and > > plug in a 10k standard resistor and in my case enter cal 9999.884 for > front and > > back. In most cases AC does not have to be done. The meter is comparing > its > > measure values with the values entered and calculates the correction > factor > > to be used each time a value is displayed. > > Most good meters now days do have a null function so you can look at > drift > > or compare 2 values. > > _______________________________________________ > volt-nuts mailing list -- volt-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts > and follow the instructions there. > -- John Phillips _______________________________________________ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.