Agilent Technologies Switch/Measure manual Voltage Measurement Configuration, DC Input Resistance

Features and Functions 2

Voltage Measurement Configuration

This section contains information to help you configure the instrument for making voltage measurements. The instrument can measure dc and true RMS ac- coupled voltages on the measurement ranges shown below.

100 mV

1 V

10 V

100 V

300 V

Autorange

DC Input Resistance

Normally, the instrument’s input resistance is fixed at 10 MΩ for all dc voltage ranges to minimize noise pickup. To reduce the effects of measurement loading errors, you can set the input resistance to greater than 10 GΩ for the 100 mVdc, 1 Vdc, and 10 Vdc ranges.

Applies to dc voltage measurements only.

DC input resistance

	Input Resistance for:	Input Resistance for:
Input Resistance Setting	100 mV, 1 V, 10 V ranges	100 V, 300 V ranges
Input Resistance: Auto OFF	10 MΩ	10 MΩ
Input Resistance: Auto ON	> 10 GΩ	10 MΩ

•The CONFigure and MEASure? commands automatically select AUTO OFF (fixed at 10 MΩ for all ranges).

•The instrument selects 10 MΩ (fixed input resistance on all dc voltage ranges) after a Factory Reset (*RST command). An Instrument Preset (SYSTem:PRESet command) or Card Reset (SYSTem:CPON command) does not change the input resistance setting.

Front Panel Operation: DMM or Channel (Configure) > INPUT RESISTANCE

Remote Interface Operation: You can enable or disable the automatic input resistance mode on the specified channels or the internal DMM. With AUTO OFF (default), the input resistance is fixed at 10 MΩ for all ranges. With AUTO ON, the input resistance is set to >10 GΩ for the three lowest dc voltage ranges.

[SENSe:]<function>:IMPedance:AUTO {OFFON} [,(@<ch_list>)]

If you omit the optional <ch_list> parameter, the command applies to the internal DMM.

34980A User’s Guide 35