The hydrophone free-field calibration in the non-anechoic water tank using continuous radiation mode

Anechoic chambers are used at free-field measurements in acoustic. Quality of the anechoic chamber estimate by comparing the dependence of sound pressure with distance between a projector and the receiver with the inversely proportional law. Creation of an anechoic water tank is a difficult technical problem. Therefore measurements in a water tank usually use tone burst radiation technique. In a non-anechoic water tank it is possible to provide free-field conditions at a continuous radiation mode. It is achieved by using a signal with the distributed spectrum and mathematical processing of results of measurements. The measurement procedure and results of free field calibration of this method are considered in the paper. Efficiency of measuring procedure was estimated by a check of the inversely proportional law in conditions of a non-anechoic water tank.