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 also describes methods of determining the pressure sensitivity by comparison with either a laboratory standard microphone that has been calibrated according to IEC 61094-2, or another working standard microphone that has been calibrated according to this 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.