I want to interface the PT 100 to meshnetics module(Zigbee wireless platform).
This module has inbuilt ADC.
The temperature range is -20 ºC to 400 ºC.
Right now I am using Wheatstone bridge with INA326 instrumentation amplifier.
This works well with Range of 0ºC to 400 ºC
So, What changes should I made to measure negative temperature?
Hi,
You can either balance the bridge , or adjust the amplifier offset to zero at -20° and reduce the gain by 5% to accommodate a range of 420°. Then, from the measured value you subtract 20° and display the value.