National Standard TCVN 9729-10:2013 - Reciprocating internal combustion engine driven alternating current generating sets - Part 10: Measurement of airborne noise by the enveloping surface method

This standard specifies measurement methods for determining the airborne noise emitted from a reciprocating internal combustion engine-driven generating set, with all noise sources, such as exhaust and cooling systems, as well as all other engine noise sources, evaluated based on comparative results. However, when the exhaust and cooling systems are ducted to a remote location, their noise contribution is excluded from this standard.

The characteristic value of the noise level is the sound power level.

Measurement results obtained in accordance with this standard are classified with grade 2 or grade 3 accuracy depending on compliance with acoustic measurement conditions. Grade 2 accuracy (e.g., engineering method according to ISO 3744) requires the measurement area to be a free sound field over a reflecting plane (with environmental correction factor K2A ≤ 2 dB) and with negligible background noise level (background noise correction factor K1A ≤ 1.3 dB). Grade 3 accuracy (e.g., survey method according to ISO 3746) requires an environmental correction factor K2A ≤ 7 dB, and a background noise correction factor K1A ≤ 3 dB.

For the operation of a generating set under steady-state conditions, this standard allows for the calculation of the A-weighted sound power level as well as octave or one-third octave band sound power with appropriate accuracy.

This standard applies to AC generating sets driven by RIC engines in stationary or mobile applications with rigid or resilient mounting. It can be used on land or at sea, but does not apply to generating sets used on aircraft, excavators, or locomotives.