Sound power is the characteristic of a sound source, it is independent of the distance and, therefore, a practical way of comparing various sound sources. Sound power can be measured in different ways (by sound pressure or by sound intensity). Sound power or acoustic power is the rate at which sound energy is emitted, reflected, transmitted or received, per unit of time. It is defined as "through a surface, the product of the sound pressure, and the component of the particle velocity, at a point on the surface in the direction normal to the surface, integrated over that surface. See the Dewesoft sound power solution.

What is the unit of sound power?

The SI unit of sound power is the watt (W). It relates to the power of the sound force on a surface enclosing a sound source, in air. For a sound source, unlike sound pressure, sound power is neither room-dependent nor distance-dependent. See the Dewesoft sound power solution.

What is sound pressure?

Sound pressure or acoustic pressure is the local pressure deviation from the ambient (average, or equilibrium) atmospheric pressure, caused by a sound wave. In the air, the sound pressure can be measured using a microphone, and in water with a hydrophone. The SI unit for sound pressure p is the pascal (symbol: Pa). Sound pressure is a property of the field at a point in space, while sound power is a property of a sound source, equal to the total power emitted by that source in all directions. Sound power passing through an area is sometimes called sound flux or acoustic flux through that area. See the Dewesoft sound power solution.

What is sound pressure level?

Sound pressure level (SPL) or sound level is a logarithmic measure of the effective sound pressure of a sound relative to a reference value. It is measured in decibels (dB) above a standard reference level. The standard reference sound pressure in the air or other gases is 20 µPa, which is usually considered the threshold of human hearing (at 1 kHz). The following equation shows us how to calculate the Sound Pressure level (Lp) in decibels [dB] from sound pressure (p) in Pascal [Pa]. See the Dewesoft sound power and sound pressure solution.

What is sound intensity?

Sound intensity, also known as acoustic intensity, is defined as the power carried by sound waves per unit area in a direction perpendicular to that area. The SI unit of intensity, which includes sound intensity, is the watt per square meter.

Which standards does Dewesoft sound power supports?

Dewesoft sound power solution is fully compliant with the following sound power standards: ISO 3741, ISO 3743-1, ISO 3743-2, ISO 3744, ISO 3745, ISO 639-3, ISO 639-4, ISO 639-5, ISO 639-6.

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Sound Power MeasurementSound power level measurement according to ISO standards

Dewesoft sound power measurement solution merges the best of both worlds: widely established sound power measurements with a familiar, distinctive user interface and industry unmatched adaptability. Rate and compare different noise sources with ease and exactness while simultaneously monitoring any number of additional parameters.

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Sound Power Measurement highlights

Supported Standards

Fully compliant with relevant sound power standards ISO 3741, ISO 3743-1, ISO 3743-2, ISO 3744, ISO 3745, ISO 6393, ISO 6394, ISO 6395, ISO 6396.

Effortless Step-by-Step Procedure

A user is guided through the entire measurement procedure with a clear and comprehensive user interface of Dewesoft X software.

Rapid Real-time and Offline Calculation

All calculated parameters are available during measurement as well as offline; rapid calculation of correction factors K1 (background noise measurement), K2 (room correction with integrated RT60 module), C1, C2, and C3 (deviations due to meteorological reasons - temperature and barometric pressure); support for raw time-domain data storing and offline sound power calculation.

Heavy Machinery

Designated measurement procedures for heavy machinery.

Predefined Report

After conducting the measurement, present your data in the pre-defined yet flexible report template.

Software included

Every Dewesoft data acquisition system is bundled with award-winning DewesoftX data acquisition software. The software is easy to use but very rich and deep in functionality. All software updates are free forever with no hidden licensing or yearly maintenance fees.

Dewesoft quality and 7-year warranty

Enjoy our industry-leading 7-year warranty. Our data acquisition systems are made in Europe, utilizing only the highest build quality standards. We offer free and customer-focused technical support. Your investment into the Dewesoft solutions is protected for years ahead.

Sound power measurement

Dewesoft offers a full sound power measurement module. Sound power is a characteristic of a sound source and it does not depend on the distance from the source. Therefore, sound power is the only practical way of comparing different sound sources.

The sound power procedure is described with standards. They define types of noise and noise sources, test environment, measurement uncertainty, criteria for background noise, criteria for air temperature and humidity, instrumentation equipment, and the position of microphones.

Dewesoft's sound power solution supports the following international standards:

ISO 3741 - specifies precision methods for determining the sound power level of a noise source from sound pressure levels measured in a reverberation test room
ISO 3744/639x - specifies methods for determining the sound power level or sound energy level of a noise source from sound pressure levels measured on a surface enveloping the noise source
ISO 3745 - specifies various methods for determining the sound power levels and sound energy levels of noise sources including machinery, equipment, and their sub-assemblies

Step-by-step Measurement Procedure

The sound power measurement procedure is guided by the simple user interface of our Dewesoft X data acquisition software.

First, you record the background noise while the sound source is off. After that, you turn on the sound source and measure the sound power level of the source. If you use the grouping of the sensor or multiple runs, repeat the procedure for each group.

Correction Factors

Correction factors are used to take into account the background noise, the influence of the room, and meteorological corrections.

K1 defines the background noise correction. This is applied in different situations. K1 can be measured before switching on the sound source.
K2 corrects the influence of the room noise. K2 correction is applied to the mean (energy average) of the time-averaged sound pressure levels over all the microphone positions on the measurement surface, to account for the influence of reflected or absorbed sound.
C1 and C2 meteorological corrections are used in the case that the air temperature at the test site is below 23°C or the altitude is higher than 500 meters above sea level.

Remote Control Operation

Trigger the start and stop of the measurement automatically by assigning remote control channels.

An example of trigger channels would be using the light barriers that are triggered when the machine enters the area. You can use one trigger channel or different trigger channels.