Abstract
In accordance with the laboratory measurement methods of the noise generated by water supply appliances and equipment specified in the ISO Standards, the noise shall be evaluated according to the noise level (Ls) specified in the installation noise standards. In the previous measurements conducted by the authors using the ISO method the sounds levels measured exhibited rather poor uniformity and reproducibility for reasons not ascertainable at that time. In the attached papers it is shown that the main reason for unreliable measurement values was intrusion of air bubbles in the test water pipes. Now accurate measurement values of the noise emitted by the water supply appliances and equipment have been successfully obtained by preventing such intrusion of air bubbles into the test water pipes.
