Null (Relative); Enabling The Null Operation - Agilent Technologies U1211A User's Manual 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
N O T E
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
to view the stored reference value. The symbol
annunciator display blinks for 3 seconds before the display turns to
zero.
annunciator display.
• Null can be set for both auto and manual range settings, but not in the
event of an overload.
• When taking resistance measurement and the meter reads a non-zero
value due to the presence of test leads, use the null function to adjust
the display to zero.
• When selecting DC current measurement, the primary display will
indicate a non-zero DC current value residual magnetism of the jaw and
internal sensor effects. Press
without clamping any conductor.
is indicated on the annunciator display.
while
Functions and Features

Null (Relative)

is blinking on the
to zero-adjust the display
3
on the
61