I used an operation amplifier for amplifing a low dc signal (about 200uv) from output of thermocoupler ,but I observed a offset voltage one the amplifier output without connecting the input dc signal , after reseach I knew there is offset voltage at the amplifier's output, it changes when ambient temperature changes, Ther are methodes to eliminate it using a variable resistor, but when ambient temperature changes you have to re-balance the variable resistor. Is ther any auto compensation.
thanks in advance.