Annex 3
Methods and instruments for measuring noise made by motorcycles
1. Noise of the motorcycle in motion (measuring conditions and method for
testing of the vehicle during component type approval).
1.1. Measuring instruments
1.1.1. Acoustic measurements
1.1.1.1. General
The apparatus used for measuring the sound pressure level shall be a sound level meter or equivalent measuring system meeting the requirements of Class 1 instruments (inclusive of the recommended windscreen, if used). These requirements are described in IEC 61672-1:2002.
Measurements shall be carried out using the time weighting "F" of the acoustic measuring instrument and the "A" frequency weighting curve also described in IEC 61672-1:2002. When using a system that includes periodic monitoring of the A-weighted sound pressure level, a reading should be made at a time interval not greater than 30 ms.
The instruments shall be maintained and calibrated in accordance with the instructions of the instrument manufacturer.
1.1.1.2. Calibration
At the beginning and at the end of every measurement session, the entire
acoustic measuring system shall be checked by means of a sound calibrator
that fulfils the requirements of Class 1 sound calibrators according to IEC
60942:2003. Without any further adjustment, the difference between the
readings shall be less than or equal to 0.5 dB(A). If this value is exceeded, the
results of the measurements obtained after the previous satisfactory check
shall be discarded.
1.1.1.3. Compliance with requirements
Compliance of the sound calibrator with the requirements of IEC 60942:2003
shall be verified once a year. Compliance of the instrumentation system with
the requirements of IEC 61672-1:2002 shall be verified at least every 2 years.
All compliance testing shall be conducted by a laboratory which is authorized
to perform calibrations traceable to the appropriate standards.
1.1.2. Instrumentation for speed measurements
The rotational speed of the engine shall be measured with an instrument meeting specification limits of at least ฑ2 percent or better at the engine speeds required for the measurements being performed.
The road speed of the vehicle shall be measured with instruments meeting
specification limits of at least ฑ0.5 km/h when using continuous measuring
devices.