Features and Functions 4
Keysight 34970A/34972A User’s Guide 211
ENVIRONMENTAL HEALTH AND SAFETY
When any channel is connected to a hazardous voltage source, the
instrument and the device under test should be supervised, following local
EHS practices to restrict access.
Backplane Switches Channel Switches
Internal
DMM Input
Reference
Sensor
Internal
DMM Input
(4W Sense)
Internal 
DMM Input
(Current)
01
10
Com
Com (4W Sense)
11
20
21
Current Channels
22
Com (Current)
98
99
97
96
Fuse
Fuse
94
93
Bank Switches
Shunt Switches
Junction
Only one of channels 21 and 22 can be connected to the internal DMM and/or 
Com at a time; connecting one channel will close the other (thus shorting the 
input “I” to “LO”). 
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. 
Connections to AC line are not recommended unless you provide external 
transient suppression.