Sec. 909. [=Duties of district inspectors of mines.=] Each district inspector of mines shall examine each mine in his district, in which men are employed, as often as practicable, and mines employing more than ten persons, at intervals not exceeding three months between examinations, noting particularly the condition of the boilers and machinery, the location and condition of the buildings, the condition of the workings of the mine, the condition of the traveling and haulways, the circulation and condition of the air and drainage, and shall see that the provisions of this act are complied with. Upon the completion of the examination of a mine, he shall within a reasonable time thereafter, report in writing to the chief inspector of mines, the conditions of the mine, showing the extent to which the provisions of this act are complied with or violated. (Sec. 913.) Sec. 910. [=District inspectors as sealers of weights and measures.=] The district inspectors of mines are hereby vested with all the powers and authority of county auditors as sealers of weights and measures in the different counties of this state, but shall exercise such authority in connection with weights and measures at mines, only. Each district inspector of mines may upon his regular examination of a mine, and shall, upon the written request of the duly authorized representatives of the miners, the owner, lessee, or agent, or the interested land owner, test the accuracy of the scales at any time, and post in the weight house a certificate provided by the chief inspector of mines, certifying the condition of the scales, provided that such tests be made at a reasonable time without unnecessary inference with the use of such scales. (Sec. 941.) [=Duty of district inspectors in case of controversy.=] In case of a controversy or disagreement between the district inspector of mines, and the owner, lessee or agent of a mine, or persons working therein, or in case of emergency requiring counsel, the district inspector of mines may call upon the chief inspector of mines for such assistance and counsel as is necessary.