In a batch plant all of the ingredients that go into the concrete are quantified by weight with special scales. These days most of them are electronic. Those scales have to be calibrated from time to time to maintain their accuracy. Calibrating is as simple as hanging predetermined weights on the scales and ascertaining the electronic gages record that weight properly.
All scales ideally need to be calibrated when first placed into service to insure precise operation. Any scale will drift away from its pristine calibration in time. Wear of mechanical components, age and degree of avail, all contribute to calibration drift. Many states require that any scale used to buy/sell predicated on weight must be NTEP approved and inspected and certified as to it’s precision. Customarily, we recommend calibration every quarter by a trained scale technician with certified test weights. Here are several factors to consider when deciding on frequency of scale calibration testing. Is the scale operating in a truculent environment? How much is this equipment being utilized, one two, three shifts, or only an abundance of times a week?