§ 27.39. Tests to determine resistance to vibration.
179 words·~1 min read·
/us/cfr/t30/s§ 27.39·A research copy — for the controlling text, always check the official state or federal source. Not legal advice.
(a)Laboratory tests for reliability and durability. Components, subassemblies, or assemblies that are to be mounted on permissible and approved equipment shall be subjected to two separate vibration tests, each of one-hour duration. The first test shall be conducted at a frequency of 30 cycles per second with a total movement per cycle of 1/16-inch. The second test shall be conducted at a frequency of 15 cycles per second with a total movement per cycle of 1/8-inch. Components, subassemblies, and assemblies shall be secured to the vibration testing equipment in their normal operating positions (with shock mounts, if regularly provided with shock mounts). Each component, subassembly and assembly shall function normally during and after each vibration test. Note: The vibrating equipment is designed to impart a circular motion in a plane inclined 45° to the vertical or horizontal.
(b)Field tests. MSHA reserves the right to conduct tests to determine resistance to vibration in underground workings to verify the reliability and durability of a methane-monitoring system or component(s) thereof where installed in connection with a piece of mining equipment.