User`s guide

203

Chapter 4 Features and Functions

34902A 16-Channel Multiplexer

This module is divided into two banks of eight channels each. All 16

channels switch both HI and LO inputs, thus providing fully isolated

inputs to the internal DMM or an external instrument. When making 4-

wire resistance measurements, the instrument automatically pairs

channel n with channel n+8 to provide the source and sense connections.

The module has a built-in thermocouple reference junction to minimize

errors due to thermal gradients when measuring thermocouples.

NOTES:

• If any channels are configured to be part of the scan list, you cannot close multiple

channels; closing one channel will open the previously closed channel.

• Current measurements on this module will require external shunt resistors.

• Connections to AC line are not recommended unless you provide external transient

suppression.

Backplane Switches Channel Switches

Bank Switches

Com

Com (4W Sense)

Internal

DMM Input

Reference

Sensor

Junction

Internal

DMM Input

(4W Sense)

100

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