30 C.F.R. § 33.21 Modification of test equipment.
Title 30 - Mineral Resources
For test purposes the unit or system may be modified, such as by attaching instruments or measuring devices, at MSHA's discretion; but such modification shall not alter its performance.
Title 30: Mineral Resources
PART 33—DUST COLLECTORS FOR USE IN CONNECTION WITH ROCK DRILLING IN COAL MINES
Subpart B—Dust-Collector Requirements
§ 33.21 Modification of test equipment.
