This new module provides means to visualize the transmission loss in a form of an easy to interpret color map. The measurement procedure is as easy as the Scan & Paint system itself. All you need to do, in order to create a transmission loss distribution, is to position a volume velocity source in the vicinity of the area you wish to measure. Drive the sound source with white noise, and carry out a scan with a Microflown PU probe over the target area. Two scans need to be carried out. One of the scans is done from the emitter side of the studied area (the same side where the sound source is positioned), the second one is done on the receiver side (the opposite side to where the sound source is located). Both scans are processed exactly in the same way as any other Scan & Paint measurement would be. In the post-processing stage, the transmission loss module would merge the two scans, calculate the local transmission loss, and overlay the image of the measured area with a color map.
The transmission loss module provides two methods by which the transmission loss can be calculated:
If the sound field is diffuse in the incident room (emitter side), the spatial average of the mean square pressure can be used to describe the energy distribution for this volume. At the transmitted room (receiver side), the intensity can be directly measured, having then enough information to calculate the TL coefficient.
In case of lack of a diffuse field on both the incident and transmitted side (emitter, receiver), the transmissibility coefficient/ In situ transparency method can be used to define the effect of insertion of the measured panel. This method uses the intensity measured at both sides of the studied surface, to estimate the effect of the structure insertion, assuming and being limited by the fact, that at the incident side, only the normal intensity is measured (deviations with the pressure method can occur for this reason).