Calibration of reference sound sourceThe reference sound source is a stable sound power source, normally built up as an axial fan. Its characteristics are specified in ISO 6926. In this standard, two alternative methods of calibration are given; calibration in free field in a hemi-anechoic room alternatively in diffuse field in a reverberation room. The two methods give, especially at the lower frequencies, a certain systematic difference.
RISE calibrates reference sound sources in free field, atlternatively diffuse field. As results, the sound power level is given A-weighted, linear and in 1/3 octave band. As an option, the directivity index in free field can be determined.
We are also accredited for calibrating reference sound sources according to ANSI S12.5.
The mains frequency and voltage used during the calibration is chosen by the client.