Standards of Weights and Measures Act, 1976
38. Weight or measure to contain number of the approved model, etc.-
Every weight or measure to which this Part applies and for which a model has been approved shall bear thereon, in such manner as may be prescribed, the number of the approved model and the number of the certificate by or under which such model was approved:
Provided that where the Central Government is of opinion that inclusion of any such particulars on any weight or measure is not possible by reason of its size or nature, that Government may exempt the inclusion of such particulars on such weight or measure.