National Instruments 24-Bit Half/Full-Bridge Analog Input Module NI 9237 - Manual (Page 15)

© National Instruments Corp. 15 NI 9237 Operating Instructions and Specifications
Excitation Voltages
Although the sensor industry does not recognize a single standard
excitation voltage level, excitation voltage levels of between
2.5 V and 10 V are common. You can program the NI 9237 to
supply 2.5 V, 3.3 V, 5 V, or 10 V of excitation voltage, and the
module can provide up to 150 mW of excitation power. Unless you
supply external excitation voltage, National Instruments
recommends that you set the excitation voltage to a value that
keeps the total power below 150 mW. The NI 9237 automatically
reduces internal excitation voltages as needed to stay below
150 mW total power.
The power consumed by a single bridge is where R is the total
resistance of the bridge.
For a quarter or half bridge, R is equal to two times the resistance
of each element. For a full bridge, R is equal to the resistance of
each element.
V
e x
2
R
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