To Make Null (Relative) Measurements - HP 34401A User Manual

Chapter 2 Front-Panel Menu Operation

To Make Null (Relative) Measurements

To Make Null (Relative) Measurements
Each null measurement, also called relative, is the difference between a
stored null value and the input signal.
Result = reading – null value
Enables null operation;
Press again to disable.
You can make null measurements with any function except
continuity, diode, or ratio. The null operation is local to the selected
function; when you change functions, null is disabled.
To null the test lead resistance for more accurate two-wire ohms
measurements, short the ends of the test leads together and then
press .
Null
The first reading taken after you press
value in the Null Register. Any previously stored value is
replaced with the new value.
After enabling null, you can edit the stored null value by
pressing (Menu Recall). This takes you to the
Shift >
" " command in the
NULL VALUE
enabled). Go down to the "parameter" level, and then edit the
displayed value.
The null register is cleared when you change functions, turn null off,
turn off the power, or perform a remote interface reset.
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To read / edit the null value, use the MATH menu.
is stored as the null
Null
(only if null is
MATH MENU
Math annunciator is on when
null operation is enabled.