a. Provide for the examination and test of any and all appliances used for the measuring of any product or service of a public utility;

b. By its agents, experts or examiners, enter upon any premises occupied by a public utility for the purpose of making the examinations and tests provided for in this chapter and to set up and use on such premises any apparatus and appliances necessary therefor;

c. Fix the fees to be paid by any consumer or user of any product or service of a public utility who may apply to the board for such examination or test to be made. Any consumer or user may have any such appliance tested upon the payment of the fees fixed by the board. If the appliance be found defective or incorrect to the disadvantage of the consumer or user such fees shall be repaid to him by the public utility.