scope:

This part of IEC 60704 specifies methods for measuring airborne acoustical noise emitted by electric refrigerators, frozen-food storage cabinets, food freezers and their combinations for household and similar uses, supplied from the mains or from batteries. The term "similar use" means "use under conditions similar to those in a household", for example, in cafés, restaurants, hotels, and similar establishments. This standard does not apply to appliances, equipment or machines designed exclusively for industrial or commercial purposes. This standard is concerned with objective methods of engineering accuracy (engineering method, grade 2, according to IS0 2204) for determining sound power levels, (LW expressed in decibels with reference to a sound power of 1 pW, of airborne acoustical noise within the specified frequency range of interest, and for specified operating conditions of the appliance to be measured. The frequency range of interest includes the octave bands with centre frequencies between 125 Hz and 8 000 Hz (this interval being, for practical reasons, narrower than the frequency range of audible sound). The following sound power levels are used: - A-weighted sound power level, LWA; - octave band sound power levels, LWOct. In general, the methods described are specified for appliances operated with no operator present. The noise measurements are made while the compressors are running. Requirements as to an indication of the noise emission values are not the subject of this standard.