The salary of mine inspectors shall be as established by the executive board.

The mine inspectors shall be allowed all necessary expenses incurred by them in enforcing the several provisions of this act in the respective courts of this Commonwealth, if they have obtained the consent of the department before such expense is incurred, the same to be paid by the State Treasurer, on warrant of the Auditor General, issued upon presentation of itemized vouchers approved by the court before which the proceedings were instituted, and also by the secretary.