The aim of this standard is to define the “conventional value of the result of weighing in air” and to fix the values of the physical constants which play a part in this definition. Furthermore it lays down: - the provisions relating to the density of weights (!) used with weighing machines and weights incorporated in these machines, - the requirements for the adjustment of weights used with weighing machines and the requirements for the setting of these machines, and specifies, - the way to use the weights and weighing machines for the weighing of bodies. - The justification for the rules adopted may be found in the Annex.