Directivity measurement frame

­The directivity is a feature of a sound source that describes the distribution of the emitted intensity according to space directions. It can thus highlight the main emission directions.

The directivity frame of UMRAE allows the measurement of the noise directivity from road vehicles in a vertical plane, when driving in real conditions. For example, it provides information on the distribution of the sound emitted towards the various building storeys and thus, contributes to characterise road transportation noise.

Portique de directivité de l'UMRAE

This arch-shaped frame, with a radius of 4.57 m, consists of eight aluminium sections. Each section, with a unit weight of 8 kg, is composed of a triangular structure made of 10 mm diameter tubes. The ends are fixed on two metal hinges (of unit weight of 50 kg) to ballast the arch. Metal bars settle on either side of the hinges in order to increase stability and bracing can be set up with straps.

18 microphone stands allow the positioning of the sensors along the arch, which is graduated on the whole half-perimeter.


Contact: Joël Lelong