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Electronic Code of Federal Regulations

e-CFR data is current as of February 26, 2020

Title 30Chapter ISubchapter BPart 27Subpart C → §27.38


Title 30: Mineral Resources
PART 27—METHANE-MONITORING SYSTEMS
Subpart C—Test Requirements


§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.

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