HP WaterSkis E1412A, WaterSkis E1312A Chapter HP E1312A/E1412A Multimeter Application Information

Integration Time Integration time is the period during which the multimeter’s analog-to-digital (A/D) converter samples the input signal for a measurement. Integration time affects the measurement resolution (for better resolution, use a longer integration time), and measurement speed (for faster measurement, use a shorter integration time).

•Integration time applies to dc voltage, dc current, resistance and four-wire resistance functions only. The integration time for the math operations is the same as the integration time for the measurement function in use.

•Except for FREQuency and PERiod functions, integration time is usually specified in number of power line cycles (NPLC). The default NPLC is 10. You can also specify an integration time in seconds for dc voltage, dc current, resistance, four-wire resistance, frequency and period using the aperture time command for each function. Aperture time has a direct correlation to NPLC (except for the FREQuency and PERiod functions which do not use NPLC) and is shown in the tables beginning on page 70. See the [SENSe:]FREQ:APER and [SENSe:]PER:APER commands for setting frequency and period aperture time.

•The integration time is stored in volatile memory. The multimeter selects 10 PLCs at power-on or after a module reset. See following information for FREQuency and PERiod aperture time.

•Only integral numbers of power line cycles (1, 10 or 100 PLCs) provide normal mode (line frequency noise) rejection.

•You cannot control the reading rate for ac measurements with integration time because integration time is fixed at 10 PLCs for all ac measurements. You must use a trigger delay to pace ac voltage and ac current measurements.

•NPLCs are not applicable to the FREQuency and PERiod functions. Frequency and period measurements set resolution by specifying aperture time. The aperture time for the FREQuency and PERiod functions default to 100mS. Specify an aperture time of 10mS for 4½-digits, 100mS for 5½-digits or 1 second for 6½-digits of resolution.

•Set integration time using the following commands:

[SENSe:]<function>:NPLC <number>

(NPLCs are not applicable for the FREQ and PER functions) [SENSe:]<function>:APER <seconds>

Chapter 2 HP E1312A/E1412A Multimeter Application Information 39