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:
(a) A Type 1 sound level meter;
(b) A Type 2 sound level meter; or
(c) A Type S sound level meter which has -
(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.