49 C.F.R. § 325.27 Use of a windscreen.
Title 49 - Transportation
A properly installed windscreen, of the type recommended by the manufacturer of the Sound Level Measurement System, shall be used during the time that noise emission measurements are being taken.
Title 49: Transportation
PART 325—COMPLIANCE WITH INTERSTATE MOTOR CARRIER NOISE EMISSION STANDARDS
Subpart C—Instrumentation
§ 325.27 Use of a windscreen.
