Various scales and weighing methods may be used to verify the weight of products for sale. Generally, if the product weight deviates from a specified target weight for a given product type by more than a specified tolerance value, the respective nonconforming product is separated out following the weighing process. Separation may be created by various rejection devices, such as a pusher, a blast nozzle, and/or a deflector. In this way, the scale provided with the rejection device checks weight to prevent products from being put into circulation which do not meet the given tolerances. For example, in the pharmaceutical field, the scale ensures, by weight calculation, the completeness of the pharmaceutical package. Preferably, each pharmaceutical package must have the same quantity of tablets, any package insert and/or the like. None of these package elements may be missing or the entire package may be separated for inspection.
Often the same scale may be used to weigh a variety of different product types. Unfortunately, for each respective product type of the product to be checked, a target weight and any associated tolerances should entered into the weighing system. The entry of the target weight and weight tolerances is usually made manually directly on the weighing instrument by the operating staff, which may result in manipulations or misadjustments and which is, in the practice, almost invariably without a direct, clear connection to the respective product being conveyed over the scale.