National Instruments NI 9472 - Manual (Page 22)

NI 9472/9474 22 ni.com
This category refers to local-level electrical distribution, such as
that provided by a standard wall outlet, for example, 115 V for U.S.
or 230 V for Europe.
Caution Do not connect the NI 9472/9474 with screw
terminal to signals or use for measurements within
Measurement Categories III or IV.
NI 9472 with DSUB Safety Voltages
Connect only voltages that are within the following limits.
Channel-to-COM .............................. 30 VDC max
Isolation
Channel-to-channel .................... None
Channel-to-earth ground
Continuous ........................... 60 VDC,
Measurement Category I
Withstand ............................. 1,000 V
rms
, verified by a 5 s
dielectric withstand test
Measurement Category I is for measurements performed on
circuits not directly connected to the electrical distribution system
referred to as MAINS voltage. MAINS is a hazardous live electrical