National Instruments NI 9219 - Manual (Page 17)

© National Instruments Corp. 17 NI 9219 Operating Instructions
Figure 10. Connections in Half-Bridge and Full-Bridge Modes
Thermocouple Mode
In Thermocouple mode, connect the positive end of the
thermocouple to HI and the negative end of the thermocouple to
LO. This mode uses the ±125 mV range of the ADC to return a
voltage reading. Use shielded cables and twisted pair wiring and
ground the shielded cables. Each channel has a built-in thermistor
for cold-junction compensation (CJC) calculations. For improved
CJC sensor accuracy, operate the NI 9219 in a stable temperature
1 The dotted line represents the portion of the circuit that is connected
only in Full-Bridge mode.
HI
LO
EX+
EX– NI 9219
R
1
R
2
R
3
R
4
ADC
Wire
Wire
1