TYPE 4939
1/4-inchFree-field Microphone, Externally Polarized
Free-field microphone designed for high-level and high-frequency measurements over a frequency range of 4 Hz to 100 kHz.
Request PriceFree-field ¼-inch microphone Type 4939 is specially designed for high-level and high-frequency measurements. By using stainless steel diaphragm and protection grid, the microphone is optimised to withstand rough environments and is capable of working at high temperatures up to 150°C (302°F).
USE SCENARIOS
- High level measurements
- High frequency measurements
- Model work
ROBUSTNESS
The microphone is capable of withstanding the IEC 68-2-32 1 metre drop test.
CALIBRATION
The sensitivity can be calibrated at 250 Hz by using Pistonphone Type 4228 with ¼-inch Adaptor DP 0775. The actuator response can be measured using Actuator UA 0033 with Adaptor DB 0264. The free-field response can be obtained by adding the type-specific, free-field correction to the actuator response.
- Capacitance
- 6.1 pF
- Diameter
- 1/4
- Dyn. range
- 28 – 164 dB
- Freq. range
- 4 – 100000 Hz
- Inherent noise
- 28 dB A
- Lower limiting frequency -3dB
- 3 Hz
- Optimised
- Free field
- Polarization
- Ext polarized
- Polarization voltages
- 200 V
- Pressure coefficient
- -0.007 dB/kPa
- Sensitivity
- 4 mV/Pa
- Standards
- IEC 61094-4 WS3F
- Temperature coefficient
- 0.003 db/ºC
- Temperature range
- -40 – 150 C
- Venting
- Side
- Weight
- gram
- Sound field
- Free-field
- Input type
- Classic
- Microphone type
- Free field
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