Trade approved Platform weighing scales certified for selling goods by weight by weighing authorities such as UNBS need to be regularly calibrated and checked to ensure they fall in line with legal requirements.

What do I need to calibrate a platform weighing scales?
Platform weighing scales weigh in much higher capacities than standard weighing scales, and therefore require specially designed block calibration weights for accurate external calibration. In the Uganda, UNBS approved block calibration weights graded in regards to their tolerance/ level of precision. It is still possible to calibrate platform weighing scales with internal calibration using external calibration weights.

How Often Should You Calibrate Your Platform weighing scales?
How often you calibrate your platform weighing scales depends on a few different factors — manufacturer's recommendations, how often you use the platform weighing scales, the environment they're in, and how essential an exact weight is to your business. Some are calibrated once per month, others are only calibrated once per year, while some are even spot checked daily for accuracy.