JJF 1202-2008
Calibration specification for electret microphones
People's Republic of China National Metrology Technical Specifications
Electret microphone calibration specifications
Posted 2008-04-16
2008-07-16 implementation
The State Administration of Quality Supervision, Inspection and Quarantine released
Electret microphone calibration specifications
ElectretMicrop
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This specification by the State Administration of Quality Supervision, Inspection and Quarantine approved on April 16, 2008, and from
From July 16, 2008 into effect.
Focal point. the National Committee of the acoustic measurement technology
Drafting. Shenzhen Academy of Metrology and Quality Inspection
China Testing Technology Research Institute
This specification metering commissioned National Technical Committee is responsible for interpreting acoustics
Drafters of this specification.
HONGKONG whole (Shenzhen Academy of Metrology and Quality Inspection)
Zhang Guoqing (Shenzhen Academy of Metrology and Quality Inspection)
Jiao Jian (Shenzhen Academy of Metrology and Quality Inspection)
Hao Yu-chuan (China Testing Technology Research Institute)
Dai Bin (Spectris China Ltd.)
Luo Yuan (Shenzhen Academy of Metrology and Quality Inspection)
Duan Xu (Shenzhen Academy of Metrology and Quality Inspection)
Li dry (Shenzhen Academy of Metrology and Quality Inspection)
table of Contents
1 Scope (1)
2. Referenced Documents (1)
3 terminology and units of measurement (1)
3.1 Sound pressure sensitivity (sound pressure response) (1)
3.2 sound pressure sensitivity level (Lm) (1)
4 Overview (1)
5 Metrological characteristics (2)
5.1 sound pressure sensitivity level (2)
5.2 Frequency Response (2)
Calibration Condition 6 (2)
6.1 environmental conditions (2)
6.2 standards and other measuring equipment (2)
7 calibration items and calibration methods (2)
7.1 calibration items (2)
7.2 Calibration method (3)
8 calibration results expression (5)
8.1 Calibration Data Processing (5)
8.2 calibration certificate (5)
8.3 calibration measurement uncertainty (5)
9 Recalibration interval (5)
Appendix A calibration certificate (6)
Evaluation Examples Appendix B electret microphone calibration Uncertainty (9)
Electret microphone calibration specifications
1 Scope
This instruction applies to calibration electret microphone calibration.
2 Citations
This specification references the following documents.
JJF 1034-2005 "Acoustic measurement terminology and definitions"
JJF 1059-1999 "Evaluation and Expression of Uncertainty in Measurement"
JJG176-2005 "sound calibrators"
GB 3102.7-1993 "Quantities and units of acoustics"
GB 3240-1982 "acoustic measurement commonly used frequency"
GB/T 14198-1993 "microphones general technical conditions"
SJ/T 9564-1995 "electret microphone quality grading standards"
IEC 60268-4.2004Soundsystemequipment-Part 4. Microphones (sound system equipment -
Four parts. a microphone)
When using this specification it should be noted that using the currently valid version of the documents cited.
3 terminology and units of measurement
This specification uses the following terminology and definitions and the related JJF 1034-2005. This specification uses
Quantities and units specified in GB 3102.7-1993.
According to the specification required, the following terminology.
3.1 Sound pressure sensitivity (sound pressure response) (Mp) pressuresensitivity (pressureresponse)
Receiving transducer output of the open-circuit voltage and the ratio of the receiving transducer on the surface of some solid sound pressure. In volts per
Pa, V/Pa.
3.2 sound pressure sensitivity level (Lm) pressuresensitivityleve1
Sound pressure sensitivity level Lm is the sound pressure sensitivity and Mp reference sound pressure sensitivity of Mr expressed in decibels.
Lm = 20lg (Mp/Mr)
Where. Mr = 1V/Pa, the reference sound pressure sensitivity.
4 Overview
Electret microphone is a prevalent electro-acoustic transducer, namely polarization plate electret material after charge