User`s guide

34410A/11A/L4411A User’s Guide 51
Features and Functions 2
DC Measurements
Integration Time and Resolution
For dc voltage, dc current, resistance, and temperature measurements, the
multimeter provides two ways to set integration time, both of which affect the
measurement resolution. These are in the number of power–line cycles
(NPLCs) and aperture (settable in seconds).
NPLC mode. Using NPLCs sets the number of power–line cycles during
which the multimeter’s analog–to–digital (A/D) converter samples the input
signal for a measurement. The multimeter automatically detects the AC line
frequency, using it and the NPLC selection to set integration time. Use a larger
NPLC value for better resolution. Use a smaller value for faster measurements.
To obtain normal mode (line–frequency noise) rejection, you must select NPLC
mode, with an integral number of power–line cycles (for example, 1, 10, or 100
NPLC). The following table shows the resulting resolution for each integration
time value (in power–line cycles) selected.
• Front Panel Operation: Select a dc measurement function (DC V, DC I, Ω 2W,
Ω 4W or Te m p ). Press as required:
...
> INTEGRATION > NPLC
Select the desired NPLC value: 0.006, 0.02, 0.06, 0.2, 1, 2, 10 or 100.
(The 34411A also allows you to select 0.001 or 0.002.) Then step through
or exit the configuration menu.
Integration Time Resolution
0.001 PLC* 30 ppm x Range
0.002 PLC
* 15 ppm x Range
0.006 PLC 6.0 ppm x Range
0.02 PLC 3.0 ppm x Range
0.06 PLC 1.5 ppm x Range
0.2 PLC 0.7 ppm x Range
1 PLC (default) 0.3 ppm x Range
2 PLC 0.2 ppm x Range
10 PLC 0.1 ppm x Range
100 PLC 0.03 ppm x Range
*Model 34411A/L4411A
UG_ED5.book Page 51 Thursday, March 1, 2012 11:28 AM