- Fri Jan 19, 2018 6:28 am
#197962
Since load cells are analog devices, your resolution is ideally infinitesimally small. In the real world, you are limited by the noise in your system and the resolution of your A/D converter.
Let's make some assumptions so I can illustrate what I'm talking about. Let's assume that you have a 10-bit A/D converter and you have built your front end electronics so that with 0kg on it, you read 0b0000000000 and with 10kg on the bar and 200kg on the disc you read 0b1111111111. 10-bits gives you 1024 discrete levels you can acquire so you simply divide the max load of the cell by 1024.
10kg bar: 10kg/1024 ~= 0.00976kg or about 10 grams as your minimum.
200kg disc: 200kg/1024 ~= 0.1953kg or about 200 grams as your minimum.
You could change your electronics so that the 200kg disc outputs a full scale A/D value with a 10kg load on it but you will introduce noise to the system that will limit your resolution since the very small output of the disc relative to the bar requires much more amplification.
-Bill
