how can I use LabView to acquire temperature from PTC's

[Ronald]

Hi,

I'd like to measure the temperature from the motor windings (electric motor,
squirrel-cage) which is equipped with PTC's. From the manufacturer I got
some of these PTC's for calibration purposes, and now I'd like to measure
the temperature of the motor windings while it is under load.

Thanks,

Ron@ld

[PdB]

3 steps:
- get a changing voltage from an input-device like a NI-daq card by using a resistive bridge measurement-setup (1/4, 1/2, full bridge).
[Note: The fact that the sensors are near high-voltage sources may give you the need for an isolated circuit.]
- calculate the PTC-resistance from this voltage.
- use an algoritm or look-up table to calculate the temperature from the resistance. The algoritm can be obtained from the manufactorer/supplier and tested by using the resitors they gave you. Always test/calibrate the internal PTC's under known temperatures (take into account long settling-times caused by all that iron).