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| International Standard Category: Acoustic measurements and noise abatement in general |
GB/T 4854.7-1999 Acoustics-Reference zero for the calibration of audiometric equipment-Part 7：Reference threshold of hearing under free-field and diffuse-field listening conditions
声学 校准测听设备的基准零级 第7部分：自由场与扩散场测听的基准听阈 ;
| Category No.: | 17.140.01 | Valid Status: | superseded |
| Issued Organization: | CSBTS | Issued Date: | 1999-03-08 |
| Implemented Date: | 1999-9-1 | Abolished Date: | |
| Superseded Standard.: | GB/T 4854.7-2008 Acoustics - Reference zero for the calibration of audiometric equipment - Part 7: Reference threshold of hearing under free-field and diffuse-field listening conditions |
Superseded Date: | 2009-2-1 |
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