Members of the committee shall serve without compensation, but shall be allowed their reasonable expenses as approved by the presiding judge of the superior court. The expenses shall be a charge upon the county in which the court has jurisdiction, and shall be paid out of the county treasury upon a written order of the presiding judge of the superior court directing the county auditor to draw a warrant upon the county treasurer for the specified amount of such expenses. All orders by the presiding judge upon the county treasurer shall be filed in duplicate with the county board of supervisors and sheriff.