Resistance Measurement (B2985B/B2987B) - Keysight B2980B Series User Manual

Function Details
Null, Offset Cancel

Resistance Measurement (B2985B/B2987B)

If the Null key is pressed when the NULL indicator is turned off, the current
resistance measurement value is set as the offset value. Just after that, the
resistance measurement is performed once, and the value that subtracted the
offset value from the actual measured value is displayed as the measurement
result. And also the NULL indicator is turned on.
If the Null key is pressed when the NULL indicator is tuned on, the null function is
disabled and the NULL indicator is turned off. Just after that, the resistance
measurement is performed once, and the actual measurement value is displayed.
212 Keysight B2980B User's Guide, Edition 1