Document ID: chunk:federal_register_of_legislation:F2021C00509:front:0:p15
Version: federal_register_of_legislation:F2021C00509
Segment Type: other
Provision Reference: 
Character Range: 46851–50903

of sound levels is hereby granted/extended/refused/withdrawn[8]2/
14. Position of approval mark on the vehicle: ...........................................................................................
15. Place:....................................................................................................................................................
16. Date:......................................................................................................................................................
17. Signature:..............................................................................................................................................
    18. The following documents, bearing the approval number shown above, are annexed to this communication:
 drawings, diagrams and plans of the engine and of the noise reduction system;
 photographs of the engine and of the noise reduction system;
 list of components, duly identified constituting the noise reduction system.
19. Remarks:
 ............................................................................................................................................................
 ............................................................................................................................................................              ............................................................................................................................................................
Annex 2

ARRANGEMENTS OF THE APPROVAL MARK

Model A
(See paragraph 5.4 of this Regulation)

a = 8 mm min

The above approval mark affixed to a vehicle shows that the vehicle type concerned has, with regard to its noise emission, been approved in the Netherlands (E 4) pursuant to Regulation No. 51 under approval No. 022439. The first two digits of the approval number indicate that Regulation No. 51 already included the 02 series of amendments when the approval was granted.

Model B
(See paragraph 5.5 of this Regulation)
a = 8 mm min

The above approval mark affixed to a vehicle shows that the vehicle type concerned has been approved in the Netherlands (E 4) pursuant to Regulations Nos. 51 and 33.[9]/ The approval numbers indicate that, at the dates when the respective approvals were granted, Regulation No. 51 included the 02 series of amendments while Regulation No. 33 was in its original form.
Annex 3

METHODS AND INSTRUMENTS FOR MEASURING THE NOISE MADE BY MOTOR VEHICLES

           1. MEASURING INSTRUMENTS

           1.1.                                              Acoustic measurements

            The sound level meter or the equivalent measuring system, including the windscreen recommended by the manufacturer shall at least meet the requirements of Type 1 instruments in accordance with IEC 651, second edition.
            The measurements shall be made using the frequency weighting A, and the time weighting F.
            When using a system that includes a periodic monitoring of the A-weighted sound level, a reading should be made at a time interval not greater than 30ms.

           1.1.1.                                        Calibration

            At the beginning and at the end of every measurement session the entire measurement system shall be checked by means of a sound calibrator that fulfils the requirements for sound calibrators of at least precision Class 1 according to IEC 942:1988. Without any further adjustment the difference between the readings of two consecutive checks shall be less than or equal to 0.5dB.
            If this value is exceeded the results of the measurements obtained after the previous satisfactory check shall be discarded.

           1.1.2.                                        Compliance with requirements

            The compliance of the sound calibration device with the requirements of IEC 942:1988 shall be verified once a year and the compliance of the instrumentation system with the requirements of IEC 651, second edition shall be verified at least