True, but one rarely (or never) needs to weigh 100g with an accuracy of 0.01g.
Originally Posted by Hexavalent
Imagine a wodden folding yardstick, 2m long. The accuray is nowhere near 1mm over the whole length but you can use it without problem to measure if a plate is 3 or 4mm thick.
Additionally most electronic balances (or, more precisely, all balances which measure the force of gravity of a mass) need to be calibrated at the place where they are used. Force of gravity changes quite a bit depending on your location. The good old beam balance avoids this by comparing the force of gravity of two masses.
Last edited by ath; 06-01-2013 at 03:05 AM. Click to view previous post history.