(It shouldn't.) Is the scale starting on zero before weight is applied? (It should.) If your scale doesn't pass those simple tests, problems other than calibration may be affecting its accuracy.

Test weights and calibration weights in ASTM or OIML providing efficient routine testing and calibration of balances and scales.

Alliance Scale, Inc. is introducing a high quality line of precision stainless steel weight sets for calibrating balances and scales used in education, food, forensic, pharmaceutical, and other ...