Measurement uncertainty of scattering coefficients in scale models.

Abstract

The measurement of the scattering coefficient is defined in ISO 17497‐1. The method evaluates random‐incidence absorption coefficients obtained from measured reverberation times for four different configurations. Measurements in a scale model reverberation chamber are preferred to real scale chambers for several reasons. Requirements in terms of time invariance are easier to fulfil and the handling of samples is simpler. Although the use of a scale model renders the measurements easier, results are still affected by an uncertainty that is currently not considered when using these results for ongoing simulations or predictions. Moreover, air absorption at very high frequencies causes the measured reverberation times to be very similar, thus influencing the validity of the results in this frequency range. This paper aims to determine the measurement uncertainty of the scattering coefficients in a scale model reverberation chamber. A simplified uncertainty model will be presented taking into account the unce...