Current textIn force on June 1, 2010Source: annual CFR editions 1996–2016
§ 325.21 Scope of the rules in this subpart.
Current wording, first on file in the 1996 annual edition.
Before Jan. 1, 2017 the record is one snapshot per annual CFR edition, revised as of October 1. This is the 2009 edition's wording. An amendment that took effect between Oct. 1, 2009 and June 1, 2010 would not appear until the next edition, so check the citations below and the Federal Register for exact effective dates.
49 CFR § 325.21 — Scope of the rules in this subpart.. Text in force on June 1, 2010. This wording effective October 1, 1996 to present. Source: govinfo, 2009 edition, https://www.govinfo.gov/app/details/CFR-2009-title49-vol5/CFR-2009-title49-vol5-sec325-21. Retrieved from FMCSR.com, https://fmcsr.com/reg/325.21?asof=2010-06-01, on October 26, 2026. Unofficial compilation; verify against the official source.
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.
Amendment history
1 distinct wording on file since Oct. 1, 1996A new entry appears whenever the regulatory words change between government snapshots. Day-precise from the eCFR (2017 onward); before that, one snapshot per annual CFR edition (revised as of October 1). Bracketed citations are the Federal Register history printed with the section.