Hi, I measure the output from my circuit between 0,1 mV to 0,8 mV at 200mV setting on my digital voltmeters. How can I measure it more sensitively at least 100 times, or amplify it 100 times so that I can know the values such as 0,427mV instead of 0,4mV? I tried it using a differential amplifier circuit with LM308, R1=R2=1K and, R3=R4=100K, and 0-18VDC but it didn't work. Maybe something was wrong which I couldn't figure it out. I appreciate any suggestions either on diff amp circuit or with any other methods.