© National Instruments Corp. 15 NI 9403 Operating Instructions and Specifications
Safety

Safety Voltages

Connect only voltages that are within the following limits.
Channel-to-COM.............................. ±30 V max on up to
8channels at a time,
Measurement Category I
Isolation
Channel-to-channel.................... None
Channel-to-earth ground
Continuous........................... 60 VDC,
MeasurementCategory I
Withstand............................. 1,000 Vrms, 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