Wyoming Administrative Code › Agency 053 - Workforce Services, Department of › Sub-Agency 0004 - Mining Inspector › Chapter 4 - UNDERGROUND COAL MINES › Subpart R - Miscellaneous › Section 75.1719-3 - Methods of measurement; light measuring instruments

Current through July 13, 2024
(a) Compliance with S 75.1719-1(d) shall be
				  determined by MSHA by measuring luminous intensity (surface
				  brightness).
(b) In measuring
				  luminous intensity the following procedures shall be used:
(1) In areas of working places specified in
				  SS 75.1719.1(e)(1) through 75.1719-1(e)(3) luminous intensity measurements of
				  the face, ribs, roof, floor, and exposed surfaces of mining equipment, shall be
				  made with the machine idle and located in the approximate center of the working
				  place with the cutting, loading, or drilling head toward the face and not more
				  than 3 feet from the face.
(2) In
				  areas of working places specified in S 75.1719-1(e)(4) luminous intensity
				  measurements may be made at any time longwall or shortwall mining equipment is
				  operated except that when measurements are made in the vicinity of shearers,
				  plows, or continuous miners, the equipment shall be idle while measurements are
				  being made.
(3) In areas of working
				  places specified in S 75.1719-1(e)(5) luminous intensity measurements of the
				  face, ribs, roof, floor, and exposed surfaces of mining equipment, shall be
				  made with the machine idle and located in the approximate center of the working
				  place with the drilling head toward the face and a distance from the face of 5
				  feet, or the distance from the floor to the roof, whichever is applicable. When
				  the machine is located in the center of the working place and the surfaces of
				  the ribs to be illuminated are not within the perimeter of the area determined
				  in accordance with S 75.1719-1(e)(5), the machine shall be positioned the
				  applicable distance from the face and each rib and luminous intensity
				  measurements made for each rib, provided, however, that luminous intensity
				  measurements may be made of the face, roof, floor, and exposed surfaces of
				  mining equipment with the machine so located without locating the machine in
				  the center of the working place.
(4) In areas of working places specified in S
				  75.1719-1(e)(6), luminous intensity measurements of a coal surface shall be
				  made with the machine idle and located in the approximate center of the working
				  place with the appropriate end toward the face and not less than 9 feet nor
				  more than 10 feet from the face.
(5) The area of surfaces to be measured shall
				  be divided into round or square fields having an area of not less than 3 nor
				  more than 5 square feet as illustrated by the following figure:
[SEE P75F1.PCX]
(6) Measurements shall be taken with the
				  photometer held approximately perpendicular to the surface being measured and a
				  sufficient distance from the surface to allow the light sensing element in the
				  instrument to receive reflected light from a field of not less than 3 nor more
				  than 5 square feet. The luminous intensity of each such field shall be not less
				  than 0.06 footlambert.
(7) In areas
				  of working places where clearances are restricted to the extent that the
				  photometer cannot be held a sufficient distance from the surface to allow the
				  light sensing element in the instrument to receive reflected light from a field
				  having an area of at least 3 square feet, luminous intensity shall be
				  considered as the average of four uniformly spaced readings taken at the
				  corners and within a square field having an area of approximately 4 square
				  feet. In such instances, the area of each of the individual readings shall not
				  exceed 100 square inches. The average of the four readings shall be not less
				  than 0.06 footlambert. The method of measurement is illustrated by the
				  following figure:
[SEE P75F2.PCX]
(8) Measurements shall not be made where
				  shadows are cast by roof control posts, ventilation equipment, or other
				  obstructions necessary to insure safe mining conditions.
(9) Where machine-mounted light fixtures are
				  used on equipment, except self advancing roof support systems, measurements
				  shall not be made of surfaces on or within 1 foot of a self-propelled
				  machine.