scope:

This standard gives values for the difference between free-field and pressure sensitivity levels for one-inch standard condensor microphones. The object of this standard is to give the values that are to be added to the pressure sensitivity level of a microphone in order to obtain the free-field sensitivity level when a very high accuracy is not called for or when conditions for carrying out an accurate free-field calibration are not available. Data are given for the commonly used types of one-inch condenser microphones, categorized according to the acoustical properties and the geometrical configurations of the microphones; they relate to microphones used without the protective grid.