law: Standards of Weights and Measures Act, 1976 
  27. Secondary or
  
  working standard, which may be stamped.  –
  Where the Central
  
  Government is of opinion that by reason of the size or nature of any secondary
  
  standard or working standard referred to in Sec. 25, it is not desirable or practicable
  
  to put a stamp thereon, it may direct that instead of putting a stamp on such
  
  secondary standard or working standard, a certificate may be issued to the
  
  effect that such secondary standard or working standard conforms to the
  
  standards established by or under this Act and every secondary standard or
  
  working standard so certified shall be deemed to have been duly stamped under
  
  this Act on the date on which such certificate was issued.