Chapter 4 Features and Functions

HP 34902A 16-Channel MultiplexerHP 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 isothermal block to minimize errors due to thermal gradients when measuring thermocouples.

 

Backplane Switches

Channel Switches

 

Internal

 

 

01

DMM Input

 

 

98

 

 

 

 

 

 

 

 

08

 

 

100Ω

Com

 

 

100Ω

Reference

 

Bank Switch

 

Junction

99

 

Sensor

 

100Ω

Com (4W Sense)

 

 

100Ω

 

 

 

09

Internal

 

 

16

DMM Input

 

 

(4W Sense)

97

 

 

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.

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