Measuring the noise level of loaded electric motors

Methods for measuring the noise level of loaded motors on the manufacturer´s test floor have been evaluated. Methods considered include quieting the loading device, utilizing a nose testing enclosure at the load test area, and utilizing the sound intensity measuring technique. Each method is examined, and the merits of each are reviewed. It is concluded that testing the noise level of loaded electric motors is feasible by any of the three methods examined. The choice of test method is dictated primarily by the nature of prevailing conditions in the manufacturer´s shop, along with considerations of economics and convenience of usage. In the case history outlined, these factors point toward the use of the sound intensity method. The test results and evaluations made using the sound intensity approach show that very good accuracy is achievable and that the method lends itself to application in a shop environment.<>