This International Standard specifies all the information necessary to carry out efficiently and under standardized conditions the determination, declaration, and verification of the airborne noise emission of liquid pumps or pump units (see 4.1). It specifies the noise measurement methods and the operating and mounting conditions that shall be used for the test. Noise emission characteristics include emission sound pressure levels at specified positions and the sound power level. The determination of these quantities is necessary for declaring the noise emission values, and purpose of noise control at source at the design stage. The determination of these quantities is also necessary for comparing the noise emitted by liquid pumps on the market. The use of this International Standard ensures the reproducibility of the determination of the airborne noise-emission characteristics within specified limits determined by the grade of accuracy of the basic airborne noise measurement method used. Noise measurement methods according to this International Standard are engineering methods (grade 2) and survey methods (grade 3). This International Standard does not deal with the characterization of the structure-borne sound and liquid-borne noise generated by liquid pumps. NOTE This International Standard is specified in EN 809+A1 for noise measurements of the Pump (or Pump Unit).