On 19 April 2018 at 16:42, <[email protected]> wrote: > -a calibration certificate without uncertainsties is totally useless. in > is not even a calibration. > -I have never understood why people are so keen on getting things > calibrated at Keysight. >
I must admit I do have some concerns, about this. There are 3 aspects to the calibration 1) Calibrate the voltage of the internal source using a 3458A. I have no concerns a 3458A is not more than capable of measuring the voltage. 2) Measure the resistors in the 16340A. What puzzles me here, is that when I had another 4339B calibrated, the limits on measuring those resistors were symmetrical about the nominal values of 1e6, 1e7, 1e8, 1e8, 1e10 and 1e11 ohms. I would have expected the limits to be asymmetrical, because those resistors are probably not their nominal value. The columns below, from left to right are Device type (whether the DUT is floating, or grounded one side). Resistor setting (ohms) Votage (V) Measurement time (Long or Short) Test limits (+/- ohm) Test results (ohm) FLOAT 1E6 100 SHORT +/- 0.0086E6 -.0019E6 FLOAT 1E7 100 LONG +/- 0.0063E7 -.0016E7 FLOAT 1E8 100 LONG +/- 0.0073E8 -.0027E8 FLOAT 1E9 100 LONG +/- 0.0093E9 -.0032E9 FLOAT 1E10 100 LONG +/- 0.0273E10 +.0095E10 FLOAT 1E11 100 LONG +/- 0.0453E11 +.0080E11 FLOAT 1E11 100 SHORT +/- 0.0550E11 +.0086E11 FLOAT 1E11 10 LONG +/- 0.0546E11 +.0113E11 GROUND 1E7 100 LONG +/- 0.0065E7 -.0017E7 GROUND 1E11 10 LONG +/- 0.0573E11 +.0107E11 That strikes me that the assumption is the values are what their nominal values are, but I wonder how accurate they are. 3) Apply known currents, again using the test box. I've asked Keysight if they are certain that the meter can be put within specification, and if not whether it might be sent outside the UK to be calibrated. To be honest, I don't really NEED the uncertainties, but the fact they can't provide them does concern me a bit. Dr David Kirkby Ph.D C.Eng MIET Kirkby Microwave Ltd Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, CHELMSFORD, Essex, CM3 6DT, United Kingdom. Registered in England and Wales as company number 08914892 http://www.kirkbymicrowave.co.uk/ Tel 01621-680100 / +44 1621-680100 _______________________________________________ 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.
