GB/T 20441.8-2025 Active

This document specifies a method for determining the free-field sensitivity of work standard microphones by comparing them with laboratory standard microphones or work standard microphones, which are calibrated in accordance with any of the following documents:
——IEC 61094-3;
——IEC 61094-2 or IEC 61094-5, and have been applied in the elements specified in IEC TS 61094-7;
——IEC 61094-6;
——This document.
This document applies to work standard microphones that meet the requirements of IEC 61094-4. It covers methods performed in acoustic environments that are very close to an ideal free-field (e.g., a high-quality free-field space) and methods that simulate free-field environments by post-processing the results to reduce the influence of defects in the acoustic environment. A comparison method based on the principles described in IEC 61094-3 is also feasible, but it is beyond the scope of this document.
Note 1: This document also applies to laboratory standard microphones that meet the requirements of IEC 61094-1, as such microphones also meet the electroacoustic specifications of work standard microphones.
Note 2: This document also applies to combinations of microphones and preamplifiers, where the measured sensitivity is related to the preamplifier's open-circuit output voltage.
Note 3: Other devices, such as sound level meters, can be calibrated using the principles of this document, but they are not within the scope of this document.