I am currently reading data from my 30kg load cell with my Arduino UNO board and passing this data to my PC. I am using INA125P to amplify the voltage of my load cell and it is established on a bread board. Here is a picture of my circuit:
Everything works fine, however when move/touch/shake my circuit a little bit the voltage output differs a lot. When this happens, I have to re-calibrate my load cell again. So here comes my question;
Why is my system messed up every time I touch my board ?
Why does my load cell needs to be re-calibrated, aren't they suppose to create a certain amount of millivolts for certain amount of strain ?