Calibration Weights are used to check the reading of scale, to make sure it is still accurate. They used when calibrating a scale.
While the calibration states how a scale behaves, adjustment of the scale changes its behavior. What it dose is a set of operations carried out on a scale so that it provides prescribed indications corresponding to given values of a quantity to be measured.
Therefore, adjusting a scale means modifying its indications in a way that allows them to correspond – as much as possible – to the quantity values of the measurement standards applied.
ANSI/ASTM Class 6 Scale Weights – For student laboratory use or low precision scales ASTM Class 6 scale weights and weight sets should be used in classroom settings or where simple weight calibrations are needed. A Class 6 scale calibration weight can be used to calibrate Class III, Class IIIL, or Class IIII digital scales, or other weighing scales. Class 6 weights are equivalent to OIML Class M2 and M3 weights