1. Regulations
  2. title 30
  3. chapter I
  4. part 27
  5. subpart C
  6. § 27.38

View all text of Subpart C [§ 27.30 - § 27.41]

§ 27.38 - Tests to determine adequacy of windows and lenses.

Impact tests. A 4-pound cylindrical weight with a one-inch diameter hemispherical striking surface will be dropped (free fall) to strike the window or lens in its mounting or the equivalent thereof at or near the center. At least three out of four samples shall withstand the impact according to the following table:

Overall lens diameter (inches) Height of fall (inches) Less than 46 4 to 59 5 to 615 Greater than 624
Lenses or windows of smaller diameter than 1 inch may be tested by alternate methods at the discretion of MSHA.

AUTHORITY: 30 U.S.C. 957, 961.

SOURCE: 31 FR 10607, Aug. 9, 1966, unless otherwise noted.

CITE AS: 30 CFR 27.38