law: Petroleum Act, 1934
  16. Certification of other test apparatus
  (1) The officer appointed under section15 shall, on payment of
  
  the prescribed fee, if any, compare with the Standard Test Apparatus any
  
  apparatus for determining the 26[flash-point] of petroleum which may be
  
  submitted to him for this purpose.
  (2) If any apparatus is found by him to agree with the Standard
  
  Test Apparatus within prescribed limits, the officer shall engrave such
  
  apparatus with a special number and with the date of the comparison, and shall
  
  give a certificate in respect of it in the prescribed form, certifying that on
  
  the said date the apparatus was compared with the Standard Test Apparatus and
  
  was found to agree with it within the prescribed limits, and specifying any
  
  corrections to be made in the results of tests carried out with the apparatus.
  (3) A certificate granted under this section shall be valid for
  
  such period as may be prescribed.
  (4) A certificate granted under this section shall, during the
  
  period for which it is valid, be proof, until the contrary is proved, of any
  
  matter stated therein.
  (5) The officer shall keep a register in the prescribed form of
  
  all certificates granted by him under this section.