Section 16 in The Standards of Weights and Measures (National Standards) Rules, 1988
16. Custody and maintenance of prototype standards
(1);The national prototype of the kilogram and other standards, equipments and objects shall remain in the custody of the National Physical Laboratory.(2);The national prototype of the kilogram, and every other national standard, standard equipment and object shall be maintained and realised periodically in accordance with such instructions as the General Conference on Weights and Measures or the International Organisation of Legal Metrology or any organisation constituted by either of them may issue from time to time.(3);Where no instructions have been issued by the International Organisation referred to in sub-rule (2), any consultative committee constituted, may compile instructions for the proper maintenance of national prototype, national standards, standard equipment and objects.(4);The National Physical Laboratory shall arrange, where necessary, to have the national prototype and national standards of physical measurements realised and established in accor-dance with the recommendations of the General Conference on Weights and Measures and to get them calibrated or intercompared with reference to the appropriate international standards of physical measurements, at periodical intervals of not more than ten years.(5);The value of the national prototype and other national standards shall be the value determined by the National Physical Laboratory or assigned by the National Physical Labora-tory on the basis of the technical information provided by the International Bureau of Weights and Measures. The National Physical Laboratory shall publish such values periodically but in any case at least once in every five years.(6);The value determined in accordance with sub-rule (5) shall be deemed to represent the highest obtainable accuracy of such value in the country.
