National Instruments NI 9215 - Manual (Page 26)

NI 9215 Operating Instructions and Specifications 26 ni.com
Caution Do not connect the NI 9215 with screw terminal
to signals or use for measurements within Measurement
Categories III or IV.
NI 9215 with BNC Safety Voltages
Connect only voltages that are within the following limits.
AI+-to-AI–........................................ ±30 V max
Isolation
Channel-to-channel .................... No isolation between
channels
Channel-to-earth ground
Continuous ........................... 60 VDC,
Measurement Category I
Withstand ............................. 1,500 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
supply system that powers equipment. This category is for
measurements of voltages from specially protected secondary
circuits. Such voltage measurements include signal levels, special