Directive 2000/14/EC of the European Parliament and of the Council of 8 May 2000 on the approximation of the laws of the Member States relating to the noise emission in the environment by equipment for use outdoors (c. 14)

ANNEX III U.K. METHOD OF MEASUREMENT OF AIRBORNE NOISE EMITTED BY EQUIPMENT FOR USE OUTDOORS

PART B NOISE TEST CODES FOR SPECIFIC EQUIPMENT

9. COMPRESSORS U.K.

Basic noise emission standard U.K.

EN ISO 3744:1995

Measurement surface/number of microphone positions/measuring distance U.K.

hemisphere/six microphone positions according to Part A item 5/according to Part A item 5

or

parallelepiped according to ISO 3744:1995 with measurement distance d = 1 m

Operating conditions during test U.K.

Mounting of equipment U.K.

The compressors shall be installed on the reflecting plane; skid-mounted compressors shall be placed on a support 0,40 m high, unless otherwise required by the manufacturer's conditions of installation.

Test under load U.K.

The compressor under test shall have been warmed up and be operating in stable conditions as for continuous operation. It shall be properly serviced and lubricated as specified by the manufacturer

The determination of the sound power level shall be made at full-load or in an operating condition that is reproducible and is representative of the noisiest operation of typical usage of the machine under test, whichever is the noisier

Should the layout of the complete plant be such that certain components, e.g. inter-coolers are mounted away from the compressor, endeavours shall be made to separate the noise generated from such parts when performing the noise test. Separation of the various noise sources may require special equipment for the attenuation of the noise from these sources during the measurement. The noise characteristics and description of the operating conditions of such parts shall be given separately in the test report

During the test the gas exhausted from the compressor shall be piped clear of the test area. Care shall be taken to ensure the noise generated by the gas being exhausted is at least 10 dB lower than the noise to be measured at all measurement locations (e.g. by the fitting of a silencer)

Care shall be taken that air discharge does not introduce any extra noise due to turbulence at the compressor discharge valve

Period of observation U.K.

The period of observation shall be at least 15 seconds