law: The Legal Metrology Act, 2009
  22. Approval of
  
  model. -
  Every person, before
  
  manufacturing or importing any weight or measure shall seek the approval of
  
  model of such weight or measure in such manner, on payment of such fee and from
  
  such authority as may be prescribed: Provided that such approval of model may
  
  not be required in respect of any cast iron, brass, bullion, or carat weight or
  
  any beam scale, length measures (not being measuring tapes) which are
  
  ordinarily used in retail trade for measuring textiles or timber, capacity measures,
  
  not exceeding twenty litre in capacity, which are ordinarily used in retail
  
  trade for measuring kerosene, milk or potable liquors:
  Provided further that
  
  the prescribed authority may, if he is satisfied that the model of any weight
  
  or measure which has been approved in a country outside India conforms to the
  
  standards established by or under this Act, approve such model without any test
  
  or after such test as he may deem fit.