9. Sound emissions produced by a motorcycle’s or moped’s exhaust system are measured using the following instruments:(1) a class 1 sound level meter that complies with IEC Standard 61672-1: 2002 published by the International Electrotechnical Commission or a type 1 or type 2 sound level meter that complies with the requirements of ANSI Standard S1.4-1983 (R2006) (including amendment S1.4a-1985) published by the American National Standards Institute, having the A-frequency weighting and F-time weighting and having the capacity to memorize the maximum value of sound emissions happening during measurement;
(2) a class 1 sound calibrator that complies with IEC Standard 60942: 2003 published by the International Electrotechnical Commission or a class 1 sound calibrator that complies with the requirements of ANSI Standard S1.40-2006 published by the American National Standards Institute, allowing to calibrate the sound level meter. A pistonphone or the internal device of a sound level meter may not be used to calibrate a sound level meter;
(3) an external tachometer allowing measurement of the rotational speed of the engine having a precision of more or less 3% and equipped with a mechanical, electromagnetic or acoustic sensor.