SoundPower (FPScript)
Calculates the sound power level. The level signals of several microphones are averaged energetically and a number of correction terms for barometric pressure, temperature, background noise, environmental correction and size of the measuring surface are considered.
Syntax
SoundPower(K0, BackgroundNoiseLevel, K2, Ls, Level1, Level2 [, ... , Leveln])
The syntax of the SoundPower function consists of the following parts:
Part |
Description |
|---|---|
K0 |
Correction term for consideration of barometric pressure and temperature. Not required by all standards. If not required, please specify 0 dB. Permitted data structures are scalar value. All numeric data types are permitted. The argument is transformed to the unit dB. The value must be greater or equal to -3070 dB and less or equal to 3020 dB. |
BackgroundNoiseLevel |
Measuring surface sound pressure level (= sound power level - measuring surface dimension Ls) of the background noise. Correction term K1 is determined from the current noise and this specification of the background noise. Please note that a result cannot be calculated if the current measuring surface sound pressure level (= measuring surface sound pressure level of the wanted noise and measuring surface sound pressure level of the background noise added energetically) is less than 3 dB above the measuring surface sound pressure level of the background noise. Permitted data structures are scalar value. All numeric data types are permitted. The argument is transformed to the unit dB. The value must be greater or equal to -3070 dB and less or equal to 3020 dB. |
K2 |
Correction term for environmental correction. Permitted data structures are scalar value. All numeric data types are permitted. The argument is transformed to the unit dB. The value must be greater or equal to -3070 dB and less or equal to 3020 dB. |
Ls |
Measuring surface dimension for the size of the measuring surface. Permitted data structures are scalar value. All numeric data types are permitted. The argument is transformed to the unit dB. |
Level1, ..., Leveln |
Two or more signals with level over time or data series with levels or individual levels of the microphone channels to be analyzed. Level over time can be calculated by the SoundLevelfunction. Permitted data structures are scalar value, data series und signal. All numeric data types are permitted. The argument is transformed to the unit dB. For the X component additional restrictions do apply. For complex data types the absolute value is formed. |
Remarks
The result has the unit dB, s.
If the unit management is switched on, the input data are converted to dB, s if necessary and otherwise it is assumed that they are in dB, s. If the input level signals are levels over time, the SoundPower function delivers the sound power level over time. The time resolution corresponds to the time resolution of the input level signals (20 ms, if the input level signals were calculated by the SoundLevel function).
If the input level signals are data series with levels (without time axis), the SoundPower function delivers a data series with sound power levels in dB.
If the input level signals are individual levels, the SoundPower function delivers the sound power level as a scalar value.
If an argument is a list, then the first element in the list is taken. If this is also a list, then the process is repeated.
Available in
Option Acoustics
Observed Standards
Standard |
Description |
|---|---|
ISO 3744, ISO 3745, ISO 3746 |
Determination of sound power levels of noise sources using sound pressure. Engineering method in an essentially free field over a reflecting plane. Precision method grades 1 (3745), 2 (3744), 3 (3746). |
DIN EN ISO 3744, DIN EN ISO 3745, DIN EN ISO 3746 |
Ermittlung der Schallleistungspegel von Geräuschquellen. (In German language) Hüllflächenverfahren der Genauigkeitsklasse 1 (3745), 2 (3744), und 3 (3746) für ein im Wesentlichen freies Schallfeld über einer reflektierenden Ebene. |
DIN 45635 |
Geräuschmessungen an Maschinen. (In German language) |
Examples
SoundPower(0.1121889072056077, 5, 0, 26.55512364789384, Signal1, Signal2)
Calculates the sound power level of the level signals 'Signal1' and 'Signal2'. The measuring surface is a sphere with a radius of 6 m with background noise of 5 dB. The temperature is 20 °C and the barometric pressure is 1013 hPa.
Use the Sound Poweranalysis object parameters for the calculation.