Null (Relative); Enabling The Null Operation - Keysight U1211A User's And Service Manual

Null (Relative)

When making null measurements, also called relative, each reading is the
difference between a stored (selected or measured) null value and the input
signal. One possible application is to increase the accuracy of a 2-wire resistance
measurement by nulling the test lead resistance. Nulling the lead is also
particularly important prior to making capacitance measurements. The formula
used for calculating null measurement is:
Result = Reading — Null value

Enabling the null operation

1 Press
2 Press
3 To exit this mode, press
– Null can be set for both auto and manual range settings, but not in the event
NOTE
– When taking resistance measurement and the meter reads a non-zero value
– When selecting DC current measurement, the primary display will indicate a
Keysight U1211A, U1212A, and U1213A User's and Service Guide
to store the displayed reading as the reference value to be
subtracted from subsequent measurements and to set the display to zero. The
symbol is indicated on the annunciator display.
to view the stored reference value. The symbol
annunciator display blinks for 3 seconds before the display turns to zero.
display.
of an overload.
due to the presence of test leads, use the null function to adjust the display
to zero.
non-zero DC current value residual magnetism of the jaw and internal sensor
effects. Press
conductor.
while is blinking on the annunciator
to zero-adjust the display without clamping any
Functions and Features
on the
3
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