Keithley 2002, Quick Function Check Procedure - Page 1
Forum section: electronics / general

author: itsbiodiversity
author_rank: Regular Contributor
timestamp: January 28, 2020, 03:35:35 pm
content: Good afternoon fellow volt nuts. I have purchased a Keithley 2002 (finally). If you were the new owner - what tests would you perform to ensure full functionality after receipt? I am limited with certain test aspects, but the equipment I have available that are relevant would be a Transmille 8041, a Fluke 8846a, various resistors, and Rigol DG1032Z (new in box - a colleague's purchase). The Transmille does have most options including 4 wire PRT, resistance, inductance, etc.I will be glad to share any results from the tests.

author: Kleinstein
author_rank: Super Contributor
timestamp: January 28, 2020, 03:57:43 pm
content: There are a few simple DMM tests one can do with little extra instruments. One is to measure the input bias current in the volts (especially 20 V range of the K2002) more at several voltages from the drift seen with a good capacitor of some 1-10 nF.Other classic tests are checking the noise with a short and the turn over error with a stable external voltage source.If a good resistor is available one could also check the stability of the resistor ranges, for the good resistors at hand.The obvious point is the instrument internal self test.The fluke 8846 would not be a real match to the K2002, so it would not help very much. It may still have reasonable calibration to do a crude check in the DC ranges.

author: itsbiodiversity
author_rank: Regular Contributor
timestamp: January 28, 2020, 04:48:40 pm
content: I have some Genrad capacitors out for cal getting their values verified at the moment. I will add I have a Genrad 1657 that I could use to compare as I tested the Genrad Capacitors to be dead on before leaving.Forgive my ignorance, but what method would you recommend for testing the input bias current in the voltage ranges?

author: Kleinstein
author_rank: Super Contributor
timestamp: January 28, 2020, 04:58:02 pm
content: For the bias test one can connect a good low DA capacitor (PP, PS or good NP0) in the 1-10 nF range and watch the voltage drift (e.g. take data at some 10 or 100 PLC to a PC). One can use any simple voltage source to get different starting points (e.g. +-18 V +- 10 V and near 0.Once DA is settled the current is given by C*dU/dt.The capacitor does not need an accurate value or temperature stability. It is not about 5% accuracy, more about the order of magnitude. Short cables and maybe a shield can help against external electrostatic pick-up.

author: TiN
author_rank: Super Contributor
timestamp: January 28, 2020, 11:48:57 pm
content: If this 2002 is older than 10 years, replacement of all electrolytic caps is a must to avoid destruction of the PCB with electrolyte. I usually replace fan as well, to keep unit nice and happy. What is your 2002 firmware version?

author: itsbiodiversity
author_rank: Regular Contributor
timestamp: February 19, 2020, 05:29:43 pm
content: When shorting using a 6" banana to banana 20 VDC Range 10 NPLC 8.5 digits it sits around 0.8 to 1.4 µV. Does this sound normal? Any other recommendations? This unit was newly built in 2016, and once warmed up checks out very nicely versus my calibrator. Within 1 year specification on most.Anyone want to recommend an accredited calibration lab to send this one off to before long?