Calibration Information
Classes of Accuracy Mass is defined by reference to the International Prototype of the kilogram and then through a hierarchy of accuracies to provide the required traceability to National Standards. The categories of weights are as follows:
E1 |
UK Primary Standard |
Stainless Steel - integral |
E2 |
UK Secondary Standard |
Stainless Steel - integral |
F1 |
UK Tertiary Standard |
Stainless steel - adjustable |
F2 |
Local Authority Standard |
Stainless steel or plated brass |
M1 |
Weights and Measures Working Standards |
Brass or cast iron |
M2 |
Traders weights |
Brass or cast iron |
M3 |
Non -trade weights |
Brass or cast iron |
Weights for testing weighing instruments have to be of an accuracy class, which will not cause apparent errors in the equipment under test. Suitable weights would be:
Class III or IIII |
Up to 5000 divisions |
M1 |
Class III |
Over 5000 divisions |
M1 up to 20kg 50% M1 over 20kg |
Class II |
Over 5000 divisions |
F2 |
Class I |
Over 50000 divisions |
E2 |