UNE 74-034-1988 acoustics. Determination of the intensity level of the noise emitted by a noise source (by means of the external method on a reflecting plane in an open area)
1.1 General This standard specifies assessment methods for measuring sound pressure levels on a measurement surface surrounding the source and for calculating the sound power level emitted by the source. Specifies the requirements for the test environment and instrumentation, as well as the techniques to be used to obtain the surface sound pressure level, from which the A-weighted sound power level of the source and the sound power levels are calculated. in octave or third octave bands. This standard specifies the fundamental acoustic requirements for noise measurements under free field conditions on a reflective plane. It is important to establish and use particular test codes for the various types of equipment to serve as a basis for measurements performed in accordance with this standard. These codes will give, for each type of equipment, detailed specifications for the assembly, loading and operating conditions of the equipment under test as well as descriptions of the measurement surface, the number of microphone positions and the measurement distance to be used. Using different measurement surfaces can lead to different estimates of the sound power level of a source. You should use the same fo