293.420.  Weighing regulations where coal miners paid by weight. — 1.  In all coal mines, the miners shall be paid by weight, and the operator of every coal mine shall provide and hereafter maintain suitable and accurate scales, which scales shall be examined, tested, and kept in thorough repair by a competent person employed by the operator, at least once in every six months; a correct record shall be kept of all coal so weighed, which record shall be open at all reasonable hours to the inspection of miners employed at the mine.  The operator shall keep at the mine weighhouse such standard United States test weights as may be prescribed by the director, for use in testing such scales; except that this section shall not apply to any operator who does not employ more than three men at any one time.  The word "miners" as used in this section shall not be construed to include those persons who mine coal mechanically and who are paid a day rate for their services, in accordance with the terms and provisions of any collective bargaining agreement between the operator and such employees.

  2.  The operator of every such coal mine shall not, before weighing the coal, pass the coal over any screen or other device which shall take any part from the value thereof, or otherwise remove any of the coal; and shall duly credit the just and merchantable weight thereof to the employee sending the coal to the surface.

  3.  The person authorized to take such weight and keep such record shall, before entering upon his duties, satisfy the mine inspector that he understands the operations and adjustment of mine scales; and shall, before entering upon his duties take and subscribe before a person authorized to administer oaths, an affidavit that he has not, and will not have while so employed any financial interest, direct or indirect, in such mine and that he will accurately weigh and carefully keep a record of all coal so weighed.  The affidavit shall be filed in the office of the clerk of the circuit court for the county, and a copy thereof kept conspicuously at the place of weighing.

  4.  Miners employed in any coal mine have the power, if they desire, of employing at their own expense, a check-weighmaster, who shall have the right to be present and observe the weighing of coal by the weighmaster, to examine and test the scales, to inspect the records made by the weighmaster; and to be subject to the same qualifications, oath and penalties as the weighmaster.