# The Lawnmowers (Harmonization of Noise Emission Standards) Regulations 1992, Paragraph 8.5: Calculation of the sound power level LWA


The sound power level LWA of the sound source is calculated by means of the following equation:
LWA=LpAm+10log10SS0+K2 where:
LWA = the sound power level of the source tested, expressed in dB (see 3.4);
LpAm = the surface sound pressure level, expressed in dB, as defined in 3.3;
S = the area of the measuring surface in m2, calculated in accordance with the method described in 8.3;
S0 = reference area of 1 m2;
K2 = correction term for the test area, expressed in dB. See last paragraph of 8.6.2.
Note(see 6.4.1)
Wherer=4m,10log10SS0=20dB. Wherer=10m,10log10SS0=28dB.

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Source: https://www.legislation.gov.uk/uksi/1992/168/schedule/3/paragraph/8.5 (the official version)
Page: https://openlegislation.uk/lawnmowers-harmonization-of-noise-emission-standards-regulations-1992/schedule-3/paragraph-8.5
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.