Hi allI want to design a 2nd order low pass active filter circuit for thermocouples , can anyone has a design of this which you have already tried and works well with thermocouples? What resistor and capacitor values you used? I have studied the tutorials for signal conditioning of thermocouples.It is written that the frequency of thermocouple signal is near about 4 Hz. What is the cutoff frequency that you set ?Please send me the circuit or a link of this. Any help will be greatly appreciated.
Long time no answer,
Firstly what type of thermocouple you want to use, coz' their voltage range is different,
You can use sallen key filter,
focus.ti.com/lit/an/sloa024b/sloa024b.pdf
below 10Hz will fit your design,