It shall be the duty of the Inspector of Weights and Measures to inspect and examine at least once in each year, all weights, measures, scale beams, patent balances, steelyards and other instruments used for the purpose of weighing and measuring in the Village, and to stamp with a suitable seal all weights, measures, scales and weighing and measuring devices so used which he may find accurate, and deliver to the owner thereof certificates of their accuracy. He shall provide a table of tolerances and specifications in conformity with those approved by the National Bureau of Standards.