Keysight Technologies 3458A Guide D'utilisation page 440

D Optimizing Throughout and Reading Rate
Table D-1
[a] For NPLC > 10, the continuous integration period is equal to the integration period of NPLC 10, but more than one
If NPLC is in the interval from 1 to 10, inclusive, then the NPLC is rounded up to
the next integer. If NPLC > 10, then the actual value of NPLC is rounded up to the
next integer multiple of 10. For values of NPLC <1, the value selected is used
much the same as aperture except that the integration period is scaled in terms of
the line frequency. For example, if the value selected for NPLC is .1 PLC, the
3458A actually sets the integration period to .1X (line period to the nearest 100
ns> or .0016666 s (60 Hz operation). The query NPLC? returns 99.9958E-3 PLC. If
the value of 2.5 is selected for NPLC, then the 3458A sets the integration period to
3 PLC. If the value of 21 is selected for NPLC, then the integration period is set to
30 PLC. NPLC 0 always selects the shortest integration period possible, 500 ns or
29.99994E-6 PLC(60 HZ operation).
Another command that affects the integration period is the resolution command,
RES, which selects the number of digits of the reading displayed as a function of a
percentage of the maximum input parameter. The resolution of the measurement
is selected as a part of the function command or as the RES command. It sets the
integration period to a value that will allow the ADC to convert the measurement
to the resolution requested.
For example,
DCV,20,.001
and
DCV,20;RES.001
440
Integration time and query response
Command
50 Hz
NPLC0 500 ns
NPLC.5 10 ms
NPLC 1 20 ms
NPLC10 200 ms
[a]
200 ms
NPLC 11
reading is taken. The resulting average is output to the display or to the GPIB.
!(using the resolution parameter of this command)
Integration time (APER)
60 Hz
500 ns
8.333 ms
16.6667 ms
166.667 ms
166.667 ms
Query response (NPLC?)
50 Hz 60 Hz
25 E-6 29.99994 E-6
500 E-3 499.99700 E-3
1
10 10
20 20
Keysight 3458A User's Guide
1