11. (1) For the purpose of verifying the correctness of the working standards, the Government may cause to be prepared as many sets of standard weights and standard measures, to be called secondary standards, as it may consider expedient and shall cause each such set to be authenticated as having been verified with the reference standards. (2) The Secondary standards shall be kept in such places and in such conditions as may be specified by the authorised person who shall cause them to be verified with the reference standards at least once in every five years and marked with the date of such verification.