plane progressive wave वाक्य

उदाहरण वाक्य

1. IEC 60268-4 specifies that frequency response should be measured in " plane progressive wave " conditions ( very far away from the source ) but this is seldom practical . " Close talking " microphones may be measured with different sound sources and distances, but there is no standard and therefore no way to compare data from different models unless the measurement technique is described.