Current textIn force on Sept. 30, 1998Source: annual CFR editions 1996–2016

§ 325.23 Type of measurement systems which may be used.

Current wording, first on file in the 1996 annual edition.

govinfo, 1996 edition ↗

Before Jan. 1, 2017 the record is one snapshot per annual CFR edition, revised as of October 1. This is the 1996 edition's wording. An amendment that took effect between Oct. 1, 1997 and Sept. 30, 1998 would not appear until the next edition, so check the citations below and the Federal Register for exact effective dates. govinfo does not publish the 1997 edition of Parts 300–399 in machine-readable form, so the 1996 text is shown for that year.

49 CFR § 325.23 — Type of measurement systems which may be used.. Text in force on September 30, 1998. This wording effective October 1, 1996 to present. Source: govinfo, 1996 edition, https://www.govinfo.gov/app/details/CFR-1996-title49-vol4/CFR-1996-title49-vol4-sec325-23. Retrieved from FMCSR.com, https://fmcsr.com/reg/325.23?asof=1998-09-30, on October 26, 2026. Unofficial compilation; verify against the official source.

The sound level measurement system must meet or exceed the requirements of American National Standard Specification for Sound Level Meters (ANSI S1.4-1971), approved April 27, 1971, issued by the American National Standards Institute, ¹ throughout the applicable frequency range for either:

¹ Copies of the specification may be secured from the American National Standards Institute, 1430 Broadway, New York, New York, 10018.

(a) A Type 1 sound level meter;

(b) A Type 2 sound level meter; or

(1) A weighing frequency response;

(2) Fast dynamic characteristics of its indicating instrument; and

(3) A relative response level tolerance consistent with those of either a Type 1 or Type 2 sound level meter, as specified in section 3.2 of ANSI S1.4-1971.

Amendment history

1 distinct wording on file since Oct. 1, 1996

Oct. 1, 1996 → presentannual editions 1996–2016viewing

A 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.