IEC 60704-2-17:2020 pdf download – HOUSEHOLD AND SIMILAR ELECTRICAL APPLIANCES – TEST CODE FOR THE DETERMINATION OF AIRBORNE ACOUSTICAL NOISE – Part 2-17: Particular requirements for dry-cleaning robots.
3 Terms and definitions This clause of IEC 60704-1:2010 is applicable except as follows: Addition : ISO and IEC maintain terminological databases for use in standardization at the following addresses: • • IEC Electropedia: available at http://www.electropedia.org/ ISO Online browsing platform: available at http://www.iso.org/obp 3.101 standard Wilton test carpet Wilton carpet on which the robot is moving during the test Note 1 to entry: The specification of the standard Wilton test carpet can be found in IEC/TS 62885-1. 3.102 standard hard floor floor of the test room on which the robot is moving during the test 3.103 fenced area area of the floor of the test room, limited by a fence, in which the robot can move around during the test 4 Measurement methods and acoustical environments This clause of IEC 60704-1:2010 is applicable except as follows: 4.2 Direct method Addition : If pure tone components are present in the noise emitted by the source, the estimated standard deviation of the measured sound pressure levels in the special reverberation room can increase. In such cases, additional microphone positions or source positions can be necessary, as specified in ISO 3743-2.
4.3 Comparison method Replacement : The comparison method for measurement is explicitly described in ISO 3743-2. NOTE 101 The term “comparison method” is not explicitly given in ISO 3744, but when applying the “absolute comparison test” for the determination of the environmental correction given in Clause A.3 of ISO 3744:2010, by using a reference sound source, the procedure is, in fact, a comparison method. With this method, the sound power level is determined by comparing the averaged values (on a mean-square basis) of the sound pressure levels produced by the source in the test room to the averaged values of the sound pressure levels produced in the same room by a calibrated reference sound source (RSS) of known sound power output, complying with the requirements of ISO 6926. The difference in sound pressure levels is equal to the difference in sound power levels when conditions are the same for both sets of measurements.
This method yields results expressed in octave-band sound power levels, and the A-weighted sound power level is calculated from the octave-band sound power levels. To check whether there is a systematic difference between results obtained in different environments, the use of the comparison method is recommended. If pure tone components are present in the noise emitted by the source, the estimated standard deviation of the measured sound pressure levels in the special reverberation room can increase. In such cases, additional microphone positions or source positions may be necessary, as specified in ISO 3743-2. 4.4 Acoustical environments 4.4.1 General requirements and criterion for adequacy of the test environment Replacement : They are given in Clause 4 of – ISO 3743-2:2018 – ISO 3744:2010 for special reverberation test rooms; for free-field conditions over reflecting plane. NOTE 101 For free-field conditions over a reflecting plane, the absolute comparison test for the qualification of the environment, described in Clause A.3 of ISO 3744:2010, is preferred. Guidelines for the design of simple test rooms with free field conditions are given in Annex C of IEC 60704-1:2010. 4.4.2 Criterion for background noise level Replacement : Requirements for the background noise level are given in Clause 4 of ISO 3743-2:2018 and ISO 3744:2010. Averaged over the microphone positions, the background noise level shall be at least 6 dB below, and preferably more than 1 5 dB below, the sound pressure level to be measured. NOTE 101 If the difference between the sound pressure levels of the background noise and the appliance noise is less than 6 dB, see 8.2 of IEC 60704-1:2010.
5 Instrumentation This clause of IEC 60704-1:2010 is applicable except as follows: 5.1 Instrumentation for measuring acoustical data Addition : The use of a microphone windscreen is recommended. If necessary, the observed sound pressure level shall be corrected for changes in the microphone sensitivity, in accordance with the instructions accompanying the instrumentation.