DIN EN 61094-5:2016-12

This part of IEC 61094 is applicable to working standard microphones with removable protection grids meeting the requirements of IEC 61094-4 and to laboratory standard microphones meeting the requirements of IEC 61094-1. This part of IEC 61094 describes methods of determining the pressure sensitivity by comparison with either a laboratory standard microphone calibrated in accordance with IEC 61094-2, or another working standard microphone calibrated in accordance with the present part of IEC 61094. Alternative comparison methods based on the principles described in IEC 61094-2 are possible but beyond the scope of this part of IEC 61094. The principle of the comparison methods is as follows: If the same sound pressure is applied to the reference microphone and the microphone under investigation, either simultaneously or with a time delay (one after the other), then the ratio of their pressure transmission coefficients is equal to the ratio of their open-circuit output voltages. The transmission coefficient of the microphone under investigation can then be calculated (by magnitude and phase) from the transmission coefficient of the reference microphone. In addition to describing the measurement procedure, this standard makes statements about the effect of various influencing variables on the measurement uncertainty, such as climate, polarization voltage, location of the microphone compensation hole for static pressure, and distribution of the sound field across the diaphragms of the microphones being compared. Examples of measurement setups with couplers and spacers for realizing the standardized measurement procedures are described in annexes, together with the maximum frequency ranges that can be used with them. A detailed example for calculating the measurement uncertainty for a hypothetical calibration report is given in another annex. The standard differs from DIN EN 61094-5:2003-02 as follows: a) treatment of measurement uncertainty clarified and further uncertainty contributions treated; b) correction values for class WS3 microphones revised; c) information on the electrical potential of the shielding made mandatory for the calibration of microphones; d) consideration of the investigated microphone in conjunction with its preamplifier added as a system. This standard contains the German version of the European Standard EN 61094-5:2016. The International Standard IEC 61094-5:2016, on which this European Standard is based, has been prepared at Technical Committee 29 "Electroacoustics" of IEC (secretariat DS, Denmark) with German collaboration. Regarding the German collaboration the responsible committee is Joint Committee NA 001-01-03 GA (NALS/DKE A 3) "Schallmessgeräte" ("Sound measuring instruments") under the chairmanship of Standards Committee Acoustics, Noise Control and Vibration Engineering (NALS) at DIN and VDI.