Set of Scales(high weight update)

Scales for the use of comparison of weight of objects. I give it to you all, with a challenge. We must all work together to make the best and most accurate set of scales that will possibly someday, tell exact weight. This is something for the community to come together and put their minds together and make it the best it can be. Because that's what we do here. Thank you.
ADDED: spring Balance
Electronic Balance