The bureau is authorized to pass upon each type of weight and measure and weighing and measuring device manufactured, offered or exposed for sale or sold or given away for the use in trade or commerce or used in trade or commerce in this Commonwealth, and to approve or disapprove of each type. The bureau shall approve each type of weight and measure and weighing and measuring device submitted to it for approval by any person if such type is so designed and constructed that it conforms to or gives correct results in terms of standard weights or measures or in terms of values derived therefrom, and is reasonably permanent in its indication and adjustment, and does not facilitate the perpetration of fraud; otherwise, the bureau shall disapprove the same. Certificates of conformance issued under the National Type Evaluation Program (NTEP), as administered by the National Conference of Weights and Measures, shall be recognized by the bureau. The director of the bureau may require any weight or measure or any weighing or measuring instrument or device to be issued a certificate of conformance, as issued by the National Institute of Standards and Technology, prior to use for commercial or law enforcement purposes. Weighing and measuring devices sold within this Commonwealth and designed to calculate a service for a charge shall only be subject to provisions of this subchapter upon issuance of a rule or regulation by the department, specifically designating which services and types of devices would be subject to type approval by the bureau. When issuing such rules or regulations, the department may grandfather by exemption devices already installed and used for calculating a service.