{"data":{"id":"us/49-cfr-325.21","jurisdiction":"us","citation":"49 CFR 325.21","heading":"Scope of the rules in this subpart.","body":"The rules in this subpart specify criteria for sound level measurement systems which are used to make the sound level measurements specified in subpart D and subpart E of this part.","path":["Title 49—Transportation","Subtitle B—Other Regulations Relating to Transportation","CHAPTER III—FEDERAL MOTOR CARRIER SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION","SUBCHAPTER A—GENERAL REGULATIONS","PART 325—COMPLIANCE WITH INTERSTATE MOTOR CARRIER NOISE EMISSION STANDARDS","Subpart C—Instrumentation"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-49.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:26:34Z","sha256":"066b6f8c0011600120093fdbe8597b6336e46d0f369e0366ab3c0e45a7bfec33","source_id":"us-cfr","stale":true,"prev":"us/49-cfr-325.13","next":"us/49-cfr-325.23"},"notice":"GroundRules: Original legal text. Not legal advice."}