National Instruments 24-Bit Half/Full-Bridge Analog Input Module NI 9237 - Manual (Page 29)

© National Instruments Corp. 29 NI 9237 Operating Instructions and Specifications
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 9237 to signals or use for
measurements within Measurement Categories II,
III, or IV.
Hazardous Locations
U.S. (UL) .......................................... Class I, Division 2,
Groups A, B, C, D, T4;
Class I, Zone 2,
AEx nC IIC T4
Canada (C-UL) ................................. Class I, Division 2,
Groups A, B, C, D, T4;
Class I, Zone 2,
Ex nC IIC T4
Europe (DEMKO)............................. EEx nC IIC T4