TCVN 7839 - 1 : 2007 - Acoustics - Determination of sound insulation performance of enclosures - Part 1: Measurements under laboratory conditions (for declaration purposes)

This standard specifies laboratory methods for determining the sound insulation (sound attenuation) performance of enclosures for small machines.

This standard does not apply to individual components of an enclosure but only to the complete enclosure.

NOTE

1 Sound insulation of enclosure components such as walls, doors, windows, silencers, etc., shall be measured in accordance with other relevant standards.

2 Standards related to the measurement of noise reduction of enclosures in situ are TCVN 7839-2 (ISO 11546-2) and in cabins (ISO 11957).

The measurement methods specified in this standard are based on ISO 3740, ISO 9614, and ISO 11200 (see Table 1). Depending on the selected method, the sound insulation (sound attenuation) performance of the enclosure is determined based on the sound power level reduction or sound pressure level reduction. This method is used for measurements at a position where the enclosure surrounds a real sound source (machine). When this method is not feasible, alternative methods such as the substitution method (see definition 3.11 and clause 7.2) or the use of an artificial sound source can be used.

This standard applies without restriction to freestanding enclosures with a volume of less than 2m³. In the case of using a real sound source to determine the sound insulation performance of enclosures with a volume exceeding 2m³, the requirements related to the maximum allowable volume must be fully met in the standard used. The real sound source method for equipment can be applied to any type of enclosure, such as enclosures fixedly attached to machines.

When using the substitution method or the artificial sound source method, the maximum volume of the enclosure is 2 m³. This method does not apply to close-fitting enclosures.

The term "laboratory conditions" used in the title of this standard indicates that the test conditions and test environment (indoors or outdoors) fully comply with the corresponding standards listed in Table 1.