- The standard hydrometers in warehouses should be sent annually for check to the Joint Excise and Customs Control Station at Calcutta for re-standardization but if no alterations are recorded after two successive annual standardizations it is unnecessary to send the instrument again (unless there is reason to suspect its accuracy), for a further period of 3 years. At the end of this further period if the instrument again shows no variation it need not be sent again for re-standardisation for another 3 years, but if it shows variation it should be sent annually until no alterations are recorded after two successive annual verifications when the 3 year rule will apply again. The hydrometers in use at spirit warehouses and those with inspecting officers in each district should, as far as possible, be checked by the Superintendent of Excise, in the course of his tours, with the standard hydrometer with him, as well as with the standard hydrometer maintained at the local spirit warehouse.
