Keysight Technologies 3458A Guide D'utilisation page 106

3 Configuring for Measurements
Table 3-10
Specifying resolution
You can specify the measurement resolution as the last parameter (%_resolution
parameter) of a function command (FUNC,ACV, ACI, etc.) or the RANGE
command.
For all analog AC voltage and current measurements %_resolution is specified as
a percentage of the command's max._input parameter. The multimeter multiplies
the specified %_resolution parameter times the max._input parameter to
determine the measurement resolution. To determine the value of the
%_resolution parameter, use the equation:
For example, suppose your maximum expected input is 10 VAC and you need 1
mVAC of resolution. The equation evaluates to:
For analog AC measurements, resolution is determined by the A/D converter's
integration time. When you specify a resolution, you are actually indirectly
specifying an integration time. Since the NPLC command can also specify an
integration time, an interaction occurs when you specify resolution as follows:
– If you send the NPLC command before specifying resolution, the multimeter
– If you send the NPLC command after specifying resolution, the multimeter
[1] You can also specify resolution using the RES command. Refer to the RES command in
106
Analog AC A/D converter relationships
Digits of resolution
4.5
5.5
6.5
[1]
%_ resolution = (actual resolution/maximum input)
%_ resolution = (0.001/10)
satisfies the command that specifies greater resolution (more integration time).
uses the integration time specified by the NPLC command, and the previously
specified resolution is ignored.
for examples showing its usage.
Power line cycles (NPLC command)
LFREQ = 60 Hz
0 – .000030
.000036 – .000360
.000366 – 1000
×
100 = 0.01
LFREQ = 50 Hz
0 – .000025
.000030 – .000300
.000305 – 1000
×
100
Keysight 3458A User's Guide
chapter 6