Standards of Weights and Measures (Enforcement) Act, 1985
22. Prohibition of sale or use of unstamped weights or measures.-
No weight or measure shall be sold, or offered, exposed or possessed for sale, or used or kept for use in any transaction or for industrial production or for protection unless it has been verified and stamped:
Provided that nothing in this section shall apply to any weight or measure which has been initially verified and stamped with a special seal referred to in sub-section (3) of section 41 of the Standards Act.