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Error in DC Measurement

Question asked by garypang on Feb 6, 2012
Latest reply on Mar 25, 2012 by cosanzeana

I am using Agilent 4142B for my transistor DC measurement (Please see the attached Experiment Setup).

I have 2 type of setup,
1. 2 separate probes connected to 4142B
2. Single probe card where the ground for both signal source are shorted with a wire and connected to the transistor with a single pin

I have a measurement error for DC measurement of the transistor (Please see the attached Measurement Data)

For Setup 1, the measurement data is normal.
For Setup 2, the current will suddenly hit the compliance during the measurement.

What will be the main issue of the measurement error?
I am suspecting if the different ground potential when we short the grounds together for Setup 2 may affect the measurement.

Hopefully someone may help in this matter.

Thank you.