EVS-EN 62585:2012

This International Standard provides information on the corrections required over a range of frequencies in order for a periodic test of a sound level meter to be performed according to IEC 61672-3. These corrections include: - corrections for the typical effects of reflections from the case of the sound level meter and diffraction of sound around the microphone; - corrections for the deviation of the typical microphone frequency response from a uniform frequency response, where the actual microphone response cannot be measured; - corrections for the influence on the frequency response of a typical microphone of a specified windscreen and any other accessory that is part of the configuration for normal use of the particular sound level meter submitted for testing. This International Standard includes  discussion  about uncertainties of measurement of the required corrections. In some instances a maximum permitted expanded uncertainty for the manufacturer or testing laboratory is given. This maximum permitted expanded uncertainty excludes any component due to the variability of different samples of artefact (for example, microphone or windscreen). It should be noted that if large uncertainties of measurement are quoted for each of the individual corrections, when they are combined to account for the configuration of sound level meter under test, the large individual uncertainties may result in a failure to conform to the maximum permitted expanded uncertainties of measurement given in Table A.1 of  IEC 61672-1:-1 and hence a failure of the sound level meter to conform to IEC 61672-1