UNBS certification mark for Platform weighing scales in UgandaHow often should platform scales be calibrated? UNBS recommends calibration at least once per year, or more frequently for high use environments such as retail, warehouses, and industrial operations. 3. What does the calibration process involve? The process includes: Initial Assessment Checking the scales mechanical and digital components. Adjustment Fine tuning the scale to ensure accurate readings. Testing Using certified weights to verify accuracy.