GOST R 8.751-2011 国家测量一致性保证体系.测量扩音器.第7部分:实验室标准扩音器的自由场与声压灵敏度水平间的差值
State system for ensuring the uniformity of measurements. Measurement microphones. Part 7. Values for difference between free-field and pressure sensitivity levels of laboratory standard microphones