I would like to build a thermopile (built in thermistor) circuit which can measure mid infrared spectrum in uV range. I found the following circuit:
I have AD8538 and I have a thermopile, so I have everything. Unfortunately I don't know how can I calibrate the thermistor circuit for compensation the ambient temperature.
Could anyone help me with any information? Thanks.
Thermistors has this non-linear characteristics, in that case, its not easy to know the temperature over the resistance value. I think there should be some information on the data sheet of the thermistor you have that shows how to calibrate the thermistor circuit. It could be an interpolation using Stein and Hart Equation or at least a table of nominal temperature vs resistance value.
Hope it helps.