Inspectors of weights and measures of this Commonwealth and sealers of the several counties and cities of this Commonwealth may seal, for use in trade or commerce, all weights and measures and weighing and measuring devices, the type of which has been approved as required by the provisions of this subchapter or specifically exempted from the necessity of approval by the provisions of this subchapter when they find that the same are within the tolerances prescribed under the rules and regulations, provided, however, that this shall not be construed as meaning that the approval of a type shall be taken as evidence of the correctness of any individual weight or measure or weighing or measuring device of that type or prevent any such inspector or sealer of weights and measures from prohibiting the use of or confiscating any individual weight or measure or weighing or measuring device which is found to be inaccurate or otherwise defective or unlawfully used.