Paragraph 8.5 Calculation of the sound power level LWA

The sound power level L_WA of the sound source is calculated by means of the following equation:

$$\mathrm{L}\mathrm{WA}=\mathrm{L}\mathrm{pAm}+10\log 10\genfrac{}{}{0.1ex}{}{\mathrm{S}}{\mathrm{S}0}+\mathrm{K}2$$

where:

• L_WA = the sound power level of the source tested, expressed in dB (see 3.4);

• L_pAm = 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)

$$\mathrm{Where}\mathrm{r}=4\mathrm{m}\text{,}10\log 10\genfrac{}{}{0.1ex}{}{\mathrm{S}}{\mathrm{S}0}=20\mathrm{dB.}$$ $$\mathrm{Where}\mathrm{r}=10\mathrm{m}\text{,}10\log 10\genfrac{}{}{0.1ex}{}{\mathrm{S}}{\mathrm{S}0}=28\mathrm{dB.}$$