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 7 Scale Weights - For rough weighing operations in physical and chemical laboratories, such as force measuring apparatus. ASTM Class 7 scale weights and weight sets should be used in environments where simple weight calibrations are needed. A Class 7 scale calibration weight can be used to calibrate Class III, Class IIIL, or Class IIII digital scales, and other weighing scales. Class 7 weights are equivalent to OIML Class M2 and M3 weights.