Keysight Technologies 3458A Guide D'utilisation page 242

6 Command Reference
AZERO
Autozero. Enables or disables the autozero function. The autozero function
applies only to DC voltage, DC current, and resistance measurements.
Syntax
AZERO [control]
control
The control parameter choices are:
control
parameter
OFF
ON
ONCE
Power-on control = ON
Default control = ON
Remarks
– When autozero is ON, the multimeter makes a zero measurement
– Notice that the control parameters OFF and ONCE have the same effect. When
242
Numeric
query equiv.
0
1
2
(measurement with the input disabled) following every reading and
algebraically subtracts the zero measurement from the reading. This
approximately doubles the time required per reading.
autozero is OFF or ONCE, the multimeter makes one zero measurement and
algebraically subtracts this from subsequent readings. After you execute
AZERO OFF or AZERO ONCE, the multimeter takes the autozero measurement
when the first trigger arm event occurs for all events except TARM EXT which
causes an autozero measurement when the TARM EXT command is executed.
The autozero measurement will be updated whenever the measurement
function, range, or integration time is changed (this update will be made when
the trigger arm event occurs or TARM EXT is executed).
Description
Zero measurement is updated once, then only after a function,
range, aperture, NPLC, or resolution change.
Zero measurement is updated after every measurement.
Zero measurement is updated once, then only after a function,
range, aperture, NPLC, or resolution change.
Keysight 3458A User's Guide