Section 6 in The Standards of Weights and Measures (General) Rules, 1987
6. Power to specify any other reference, secondary or working standard measurements
.-(1) Any other reference standard, or secondary standard, or working standard shall conform as regards the denomination, material used in construction, and design, to such specifications as the Central Government may, from time to time, by notification, specify.(2)The maximum permissible error in relation to such other reference standard, or secondary standard, or working standard shall be such as the Central Government may, from time to time, by notification, specify and different maximum permissible error may be specified in relation to different types of reference standards, or secondary standards, or working standards.
