Hi. I have a situation like this where I am trying to amplify the output signal of a pyranometer sensor from 0-7.152mV to 0-2.56V so that at the end I can digitalize the signal with an ardunio's ADC. The pyranometer is the same one as mentioned before but mine gives out 4.47uV per W/m2. I am using an instrumental Amplifier (AD620AN) with a total gain of 351. The simulation of the amplification works flawlessly, as well as the wired circuit, but only when I test it with a voltage sweep and not the real sensor. My problem is, how should I connect the sensor to the amplification circuit? The sensor has three output wires: blue (low), red (high) and black (ground). I also looked at how the sensor worked and even though I didn’t understand it perfectly, I'm pretty sure it uses a thermistor circuit and some thermocouples or something. When I measure the voltage difference between the blue and red wire I get the desired 4.47uV per W/m2 ratio. I believe that the output should be treated as a thermocouple and should be grounded before entering the OpAmp. Based on some information I gathered before, I ended up wiring the sensor the way it is shown in the image 'Pyranometer OpAmp INA'. I will also attach the sensor circuit diagram of the pyranometer.
Thanks and hope to have a reply soon. Any other suggestions are also welcomed.
Thanks and hope to have a reply soon. Any other suggestions are also welcomed.
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