I want to build a weight scale with 0.1 gram resolution. But I have some problems in my initial stage.
I am using a load cell with sensitivity of 1mV/V and excitation voltage of 3 V.
With no weight, the load cell output shows -0.089 mV and with full load (500gms) it shows 2.895 mV. Is -0.089 mV the noise of my load cell? If so, how could I solve this problem? Why is my load cell mot showing an output of 3mV for 3 V of supply?
I have connected the load cell to IN amp (PMI AMP04FP) with a gain of 100, with no load, I get an output of 3.203 mV and with full load I am getting an output of 278 mV. Why is the IN amp showing an output of 3.203 mV? Is it the offset voltage? If so how could I solve the problem? Why am I getting 278mV instead of 300mV?
I have gone through the basics. But couldn't get my mind clear because of a lot of information in a small time. I know that my questions are basic and need some reading. I would be glad if someone could explain me what is happening and how to proceed. I am willing to learn. So, any kind of help (links, books etc) is appreciated.