Keysight Technologies 3458A Guide D'utilisation page 78

3 Configuring for Measurements
If autocal is secured (it is not secured when shipped from the factory), you must
enter the security code to perform autocal; refer to the ACAL command in
Chapter 6
first, followed by OHMS and AC) by sending:
OUTPUT 722; "ACAL ALL"
Always disconnect any input signals before performing autocal. If you leave an
input signal connected to the multimeter, it may adversely affect the autocal and
subsequent measurements.
When to use autocal
For maximum accuracy, we recommend performing ACAL ALL once every 24
hours or when the multimeter's temperature changes by ± 1
last externally calibrated or from the last autocal. (We recommend that the
calibrator store the multimeter's internal calibration temperature using the
CALSTR command; this can be read later using the CALSTR? command.) The
following example shows how to use the TEMP? command to monitor the
multimeter's internal temperature (in degrees Celsius).
10 OUTPUT 722;"TEMP?"
20 ENTER 722;A
30 PRINT A
40 END
The autocal constants are stored in continuous memory (they remain intact when
power is removed). Therefore, it is not necessary to perform autocal simply
because power has been cycled.
Selecting the input terminals
The multimeter has both front and rear terminals for measurement connections.
The front panel Terminals switch allows you to select between the two
(depressed = Rear, out = Front). You cannot select the input terminals from
remote. The measurement connection illustrations in this chapter show the front
terminal connections only. For rear terminal connections, connect each wire to
the similarly labeled rear terminal. We recommend high impedance, low dielectric
absorption cables for all measurement connections.
78
for more information. You can perform all of the autocal routines (DCV
°
C from when it was
Keysight 3458A User's Guide