What is a calibration weight?
Calibration weights are precision reference masses used to check and adjust the accuracy of a balance or scale. Each weight is manufactured and classed to an OIML accuracy standard, from the coarser M1 class through to the finer E2 class used with analytical balances.
SmartLabs stocks OIML calibration weight sets across the common accuracy classes and capacities, so you can match a set to the balance you need to verify.