©
National Instruments Corp.
19
NI 9222/9223
Meas
u
rement Category I is for meas
u
rements performed on
circ
u
its not directly connected to the electrical distrib
u
tion system
referred to as
MAINS
voltage. MAINS is a hazardo
u
s live electrical
s
u
pply system that powers eq
u
ipment. This category is for
meas
u
rements of voltages from specially protected secondary
circ
u
its. S
u
ch voltage meas
u
rements incl
u
de signal levels, special
eq
u
ipment, limited-energy parts of eq
u
ipment, circ
u
its powered by
reg
u
lated low-voltage so
u
rces, and electronics.
Caution
Do
not
connect the NI 9222/9223
to signals or
u
se for meas
u
rements within Meas
u
rement Categories II,
III, or IV.
Hazardous Locations
U.S. (UL) .......................................... Class I, Division 2,
Gro
u
ps A, B, C, D, T4;
Class I, Zone 2,
AEx nA IIC T4
Canada (C-UL) ................................. Class I, Division 2,
Gro
u
ps A, B, C, D, T4;
Class I, Zone 2,
Ex nA IIC T4
E
u
rope (DEMKO)............................. Ex nA IIC T4
