law: Petroleum Act, 1934
  19. Certificate of testing
  27[(1) The testing officer after testing samples of petroleum
  
  shall make out a certificate in the prescribed form, stating whether the
  
  petroleum is petroleum Class A or petroleum Class B or petroleum Class C, and
  
  if the petroleum is petroleum Class B or petroleum Class C, the flash point of
  
  the petroleum.
  (2) The testing officer shall furnish the person concerned, at
  
  his request, with a certified copy of the certificate, on payment of the
  
  prescribed fee, and such certified copy may be produced in any Court in proof
  
  of the contents of the original certificate.
  27[(3) A certificate given under this section shall be admitted
  
  as evidence at any proceedings which may be taken under this Act in respect of
  
  the petroleum from which the samples were taken, and shall, until the contrary
  
  is proved, be conclusive proof, that the petroleum is petroleum Class A or
  
  petroleum Class B or petroleum Class C, and, if the petroleum Class B or
  
  petroleum Class C, of its flash-point.]