This part of ISO 13475 specifies the test conditions by which the sound emission level of stationary audible warning devices can be obtained. The methods are applicable to sirens for use in public outdoor warning systems and sound signalling devices for use outdoors. The purpose of this test code is to be able to produce reliable sound emission level measurements for stationary sirens used for warning outdoors. This part of ISO 13475 does not cover spoken messages and contains no recommendations for specific warning signals.