Keysight DAQ970A User Guide

Four-Wire Multiplexers
You can make 4-wire ohms measurements using the DAQM900A, DAQM901A, and DAQM902A mul-
tiplexers. For a 4-wire ohms measurement, the channels are divided into two independent banks by open-
ing the bank relay.
For 4-wire measurements, the instrument automatically pairs channel n with channel n+10 (DAQM901A)
or n+8 (DAQM902A) to provide the source and sense connections. For example, make the source con-
nections to the HI and LO terminals on channel 2 and the sense connections to the HI and LO terminals on
channel 12.
If any channels are configured to be part of the scan list, you cannot close multiple channels; clos-
ing one channel will open the previously closed channel.
When making a 4-wire measurement, the test current flows through the source connections from the HI
terminal through the resistor being measured. To eliminate the test lead resistance, a separate set of sense
connections are used as shown below:
Keysight DAQ970A User's Guide 213
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Keysight DAQ970A Specifications

General

Scan Rate	Up to 450 channels/sec
Connectivity	USB, LAN, GPIB (optional)
Display	4.3-inch color LCD
Operating Temperature	0 °C to 50 °C
Number of slots	3 slots
Measurement Types	DCV, ACV, DCI, ACI, 2-wire resistance, 4-wire resistance, frequency, temperature, capacitance
Voltmeter	6.5 digit
Resolution	22 bits
Memory	Non-volatile memory