Hello. I have a micro pressure sensor. It consists of a wheatstone bridge and all of the 4 resistors are strain gauges.

When temperature increases from 20 Celcius to 40 celcius at constant pressure, output voltage of the wheatstonebridge changes from 17 microvolts to -10 microvolts. I want to know the reason. I heard that wheatstonebridges with 4 strain gauges should not be affected by the temperature.

Thanks for your help.

 

Unless you were very careful in setting up your instrumentation there is a very good chance that some of the drift is from thermally induced offsets in your instrumentation and wiring. Have you considered that?

What is the manufacturer's specification for temperature stability?

 

hi Ege,
How is the PreSensor connected, post a diagram showing the voltages etc.

 

At such low voltages you should consider thermoelectric effects.
http://download.flukecal.com/pub/literature/p18-21.pdf