Keysight Technologies 3458A Guide D'utilisation page 105

Configuring for Measurements 3
measurements; refer to the APER command in Chapter 6 for more information.)
The multimeter multiplies the specified number of PLCs by the period of the A/D
converter's reference frequency (LFREQ command) to determine the integration
time. For example, the period of a 50 Hz power line is 1/50 = 20 msec. If you
specify 10 PLCs, the integration time is 200 msec. In the power-on state,
integration time is set to 10 PLCs. In the PRESET NORM state, integration time is
set to 1 PLC. To set the integration time for the fastest measurements (with the
lowest accuracy and 4½, digits of resolution), send:
OUTPUT 722; "NPLC 0"
To specify the most accuracy and Highest resolution (6½ digits),with the slowest
measurement speed, send:
OUTPUT 722; "NPLC 1000"
You can specify power line cycles in the following ranges:
– 0 - 1 PLC (in .000006 PLC steps for 60 Hz ref. frequency or .000005 PLC steps
for 50 Hz ref. frequency)
– 1- 10 PLC in 1 PLC steps
– 10 - 1000 PLCs in 10 PLC steps
For integration times greater than 10 PLCs, the multimeter averages a number of
NOTE
readings made using 10 PLCs of integration time. For example, if you specify
60 PLCs of integration time, the multimeter averages six 10 PLC readings.
Typically, you should select the integration time that provides adequate speed
while maintaining an acceptable amount of accuracy and resolution. Table 3-10
shows the relationships between integration time and digits of resolution for
analog AC measurements.
Keysight 3458A User's Guide 105