Safety, Maximum voltage – National Instruments NI 9478 User Manual
Page 23

© National Instruments Corp.
23
NI 9478 Operating Instructions and Specifications
Safety
Maximum Voltage
1
Connect only voltages that are within the following limits.
V
sup
-to-COM..................................... 50 VDC,
Measurement Category I
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
equipment, limited-energy parts of equipment, circuits powered by
regulated low-voltage sources, and electronics.
Caution
Do not connect the NI 9478 to signals or use for
measurements within Measurement Categories II, III,
or IV.
1
The maximum voltage that can be applied or output between V
sup
and COM without
creating a safety hazard.