A subpoena or any notice may be delivered or sent to any sheriff, or any police officer who shall forthwith serve it and make due return thereof according to direction. Every person who is summoned by an arbitration board and who duly attends as a witness, except witnesses summoned at the request of a party, shall be entitled to an allowance for expenses determined in accordance with the scale in effect at the time with respect to witnesses in the district court in civil cases, and the allowance paid shall be a part of the general expenses of the arbitration board. The board shall have the same power and authority to maintain and enforce order at the hearings and obedience to its writs of subpoena as is by law conferred upon the district court for like purposes.