Hello all,
according to Volume and Surface Resistivity Measurements of Insulating Materials Using the 6517B Electrometer/High Resistance Meter | Tektronix
 Icalc is a weighted average of the latest four current measurements, each at the end of a separate alternation.

Could you help to advise how to define the Weight of the four current measurement.  is it 0.25 for each current measurement or other?

And  I don't quite understand about below parameter for Standard method resistivity tests

PRE-DISCH: The predischarge time in seconds. 

BIAS-TIME: The bias time in seconds. 

MEAS-V: The measurement voltage. This is typically set to the same level as BIAS V. 
MEAS-TIME: The measurement time in seconds. 

what is BIAS-TIME, and what is the difference between predischarge time and measurement time