remeasure needed for a correct reading

[Alom]

I run a a Keithley 2400 with labview 8.6 for electrical validation. Once in a while, I would get reading that is a bit off (100 ohm diff). I would remeasure it and get it right. Some say it may be the pressure i apply to the probes. I also run a machine that does the same. The machine should have constant pressure applied to the probes, but usually it needs to remeasure to get a right reading. is this some kind of timing issue?

[pflores]

I have not heard of such an issue resulting from timing. As you are getting similar results from two devices, it may be something in your physical setup. What is the other machine you are using? How are you communicating with these instruments (GPIB, serial, etc.)? Sounds like you are making resistance measurements, try connecting a constant resistor and see if the value fluctuates.

[Alom]

the machine is a Suss PA200 (semiautomatic probe tester). for the keithley and labview, i use a GPIB to USB or sometimes a RS232 to USB. I'll try to connect a constant resistor and see.

[xdaf]

Remember that if you're performing a pulsed measurement, KE2400 has about 20ms delay with default FILTER (mobile average samples) and RATE (number of power line cycles) values.