Transmission loss measurements

Transmission loss measurements

Transmission loss measurements of materials become possible without the need to use infrastructure. The two traditionally used methods, the “conventional” transmission loss technique and the P-P probe based sound intensity technique, require the availability of an infrastructure. Both methods require a reverberant room, in which a diffuse sound field is generated to excite the structure, and an anechoic room where the receiving sound field is measured. A single pressure microphone is used to measure the incident sound power.

Transmission loss

Essentially, from in instrumentation point of view, the only difference between both methods is the fact whether a sound pressure transducer or a sound intensity probe is used to measure the transmitted sound power. Whereas sheer sound pressure based sound receiving measurements only provide an overall characterization of the test panel, sound intensity based measurements allow the differentiation on various parts of the panel. Thus, flanking noise effects can be compensated to some extent.

Microflown enabled based transmission loss would require no infrastructure.  In its most elementary form only a calibrated volume velocity sound source and a single PU probe is required. The concept and working principle of this application has been proven. We are open minded to have partners out of the market or research institute to further develop and commercialize this application. 

Step 1

Step 2

By adding a second PU probe in the set up, also the acoustic reflection and impedance can be determined.

Transmission loss

The method can also be extended to PU probe array types of measurements, e.g. for in stationary sources.

Transmission loss