The point that I am making is that the manufactures themselves (Both Boeing and Airbus) admit to tolerance levels in their aircraft fuel gauging systems therefore your observed accuracy levels of "10kgs" may not be as accurate as you would like to assume. Certainly when loading 150 tons onto a Jumbo even minor SG errors will vastly swamp these figures. Just because the ecam reads to 10kgs don`t assume that that is the true accuracy level.