Determine the pump sound level
Every rotating pump makes a noise. For sources of noise which are emitted in the open air, the sound level decreases by 6 dB (A) when the distance is doubled. The table shows the change in the noise level at different distances from the source.
For example, if we use a diesel driven pump as the source of the noise, this has an LWA value of 90. That means 90 dB (A) at 0 meters distance from the pumpset. If we then compare at a distance of 33 feet (10 meters) away from the pumpset, then the calculation is:
LWA-value: 90
Distance: 33 ft (10 meters)
Correction: -28,0 dB(A)
Noise level of the pumpset at 33 ft (10 meters): 62 dB(A)
distance to heart sound source | Correction (c) |
ft | dB(A) |
3,3 | 8,0 |
6,6 | 14,0 |
9,9 | 17,5 |
13,2 | 20,0 |
16,5 | 22,0 |
19,8 | 23,5 |
23,1 | 24,9 |
26,4 | 26,0 |
29,7 | 27,1 |
33 | 28,0 |
49,5 | 31,5 |
66 | 34,0 |
82,5 | 35,9 |
99 | 37,5 |
115,5 | 38,9 |
132 | 40,0 |
148,5 | 41,0 |
165 | 42,0 |
181,5 | 42,8 |
198 | 43,5 |
231 | 44,9 |
264 | 46,0 |
297 | 47,1 |
330 | 48,0 |
363 | 48,8 |
396 | 49,6 |
429 | 50,3 |
462 | 50,9 |
495 | 51,5 |
528 | 52,1 |
561 | 52,6 |