10 Keysight 34921A-34925A User’s Guide
Measurement Functions for the Multiplexer Modules
The MUX modules support the DMM measurement functions shown in the
following table.
[a] Direct current measurements are allowed on channels 41 through 44 only (for all other channels, external shunts are required).
[b] Optional 34921T Terminal Block is required for thermocouple measurements with built-in internal reference junction.
[c] A fixed or external reference junction temperature is required for thermocouple measurement with this module.
[d] Impact of higher offset voltage specification (< 50 μV) must be taken into consideration.
[e] 1 kΩ or higher range used unless 100Ω series resistors are bypassed on module.
[f] 10 kΩ or higher range used for loads over approximately 300Ω due to series resistance of FET channels.
Measurement Function(s)
34921A
40-ch
Armature
Mux
34922A
70-ch
Armature
Mux
34923A
40-ch
Reed Mux
(2-Wire)
34923A
80-ch
Reed Mux
(1-Wire)
34924A
70-ch
Reed Mux)
34925A
40-ch
FET Mux
(2-Wire)
34925A
80-ch
FET Mux
(1-Wire)
Voltage, AC/DC Yes Yes Yes Yes Yes Yes Yes
Current, AC/DC
Yes
[a]
No No No No No No
Frequency/Period Yes Yes Yes Yes Yes Yes Yes
Ohms 2-Wire Yes Yes
Yes
[e]
Yes
[e]
Yes
[e]
Yes
[f]
Yes
[f]
Ohms 4-Wire Yes Yes
Yes
[e]
No
Yes
[e]
Yes
[f]
No
Thermocouple
Yes
[b]
Yes
[c]
Yes
[c],[d]
Yes
[c],[d]
Yes
[c],[d]
Yes
[c]
Yes
[c]
RTD 2-Wire Yes Yes
Yes
[e]
Yes
[e]
Yes
[e]
No No
RTD 4-Wire Yes Yes
Yes
[e]
No
Yes
[e]
Yes
[f]
No
Thermistor Yes Yes
Yes
[e]
Yes
[e]
Yes
[e]
No No