Looking for someone that can calibrate my Keithley 2000 (NL) - Page 1
Forum section: electronics / general

author: hhoef
author_rank: Newbie
timestamp: February 17, 2023, 09:15:47 am
content: Hi,I have repaired a Keithley 2000 multimeter and looking for someone in Holland to help me with calibrating it to a usable level.BR,Hubert

author: alm
author_rank: Super Contributor
timestamp: February 17, 2023, 01:19:28 pm
content: What do you mean with calibration? In the metrology community, calibration means a documented comparison to a standard. Something like "On February 17 I measured a resistor, that I have previously measured to be 10 kOhm +/- 1 Ohm, using this Keithley 2000 as 10.002 kOhm +/- 5 Ohm". Do you have any requirements re tracibility to national standards bodies? Are you expecting adjustments to be made?

author: hhoef
author_rank: Newbie
timestamp: February 19, 2023, 09:44:45 pm
content: If that's the case, I posted in the wrong group.The mentioning of "Calibration" in the group description made me think I could be in the correct group.I'm very sorry, I will look for the correct one.

author: alm
author_rank: Super Contributor
timestamp: February 19, 2023, 10:25:37 pm
content: No, you're not posting in the wrong group, this is the correct group in my opinion. It's just that the word calibration has somewhat different meanings depending on who you ask, so that's why I asked you to specify what you want. If you would ask someone for calibration expecting your meter to be adjusted to be as accurate as possible, and then all you get is a piece of paper saying "At time X meter Y was measured to be 20% off", then you wouldn't be very happy, I thinkI might be able to help if what you need is to adjust a meter that's severely out of tolerance (major repair or loss of calibration NVRAM) to be pretty close, or could do a series of measurements according to the performance verification and my best estimate of the uncertainty, but this wouldn't be traceable (in any formal way) to any national standards body.What I have is the necessary sources (calibrators) to generate the signals it wants, including the AC signals, some 8.5 digit meters, and some standards (10 V, 10 kOhm) that I have compared with other nuts. Based on that I have done inter-comparisons with other voltnuts in the past, and that the stability of this equipment as specified by the manufacturer is quite a bit better than the Keithley 2000, I have some degree of confidence in their accuracy. This does not come even remotely close, however, to what is considered traceable calibration like you would get if you send it to Tektronix/Keithley, Fluke, Keysight, etc.

author: J-R
author_rank: Super Contributor
timestamp: February 19, 2023, 11:24:56 pm
content: I always prefer to use the original manufacturer's terms. As the OP stated, Keithley point-blank simply calls this a "Calibration" and there is a dedicated manual for it: "Model 2000 Multimeter Calibration Manual"https://download.tek.com/manual/2000-905-01(F-Aug2007)(Cal).pdfI would suggest following the "Performance Verification" section as best you can to determine if the unit needs a comprehensive calibration or just DC or AC. If it's just DC, you could probably get by with meeting up with someone with basic equipment and a DMM with a recent calibration. If you need AC as well, it's going to be a bit more effort for a hobbyist unless you have connections to someone with a somewhat next-level of equipment, as alm hinted to. The 1kHz high-voltage and current inputs are particularly tricky, but can be done in a somewhat crude manner, such as with a signal generator, audio amp and step-up transformer.If you check out the specifications of most DMMs, you will see that for the typical hobbyist it is not necessary to get too far into the volt-nut territory, as especially the 1 & 2 year limits are particularly poor and you're basically throwing out the last two digits on DC and up to the last four on AC. For example, the 700.000V @50kHz reading can be between 698.785V and 701.215V as pointed out in the Calibration Manual.There is also the "Manufacturing calibration" which has some additional AC calibration steps, which add 1V 10Hz and 1kHz.