OM-USB-TEMP-AI User's Guide
Signal I/O Connections
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Figure 7. Four-wire, single RTD or thermistor sensor measurement configuration
A four-wire, single-sensor connected to the second channel of a channel pair is shown in Figure 8.
Figure 8. Four-wire, single RTD or thermistor sensor measurement configuration
A four-wire, two-sensor measurement configuration is shown in Figure 9.
Figure 9. Four-wire, two RTD or thermistor sensors measurement configuration
When configured for four-wire, two sensor mode, both sensors must be connected to obtain proper
measurements.
Semiconductor sensor measurements
Semiconductor sensors are suitable over a range of approximately -40
°
C to 125
°
C, where an accuracy of
±2
°
C is adequate. The temperature measurement range of a semiconductor sensor is small when compared to
thermocouples and RTDs. However, semiconductor sensors can be accurate, inexpensive and easy to interface
with other electronics for display and control.
The OM-USB-TEMP-AI makes high-resolution measurements of semiconductor sensors, such as the LM36 or
equivalent, and returns a 32-bit floating point value in either a voltage or temperature format.
Use
Insta
Cal to select the sensor type (TMP36 or equivalent) and the sensor input channel to connect the
sensor.
