National Instruments NI 9421

NI 9421/9423 20 ni.com
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.
Note Do not connect the NI 9421 with DSUB 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)............................. Ex nC IIC T4