The state sealer shall have charge of all the apparatus and property, belonging to the state, intended for the inspection of illuminating gas and gas meters, and the testing of the registration of meter provers; he shall test the registration of all meter provers that are presented to him for that purpose, and stamp and seal all such meter provers, so tested, that are found correct. For testing the registration of gas meter provers, to be paid by the persons requiring such service, he shall be allowed the sum of five dollars per hour, but not more than fifty dollars for each meter prover tested.