4950 1/2-Inch Free Field Microphone
This prepolarized, free-field ½-inch microphone is specially designed for equipment intended for accurate and reliable sound measurements in accordance with IEC 61672 Class 1 and ANSI S 1.4 Type 1.
- Sound measurements according to IEC 61672 and ANSI S 1.4 – 1983
- Cost-effective sound measurements
- ideal for cost-effective, portable instruments intended for use under different conditions including humid and polluted atmospheres.
½-inch Free-field Microphone Type 4950 is a prepolarized condenser microphone, designed for accurate and reliable sound measurements as required for sound level meters in accordance with IEC 61672 Class 1 and ANSI S 1.4 Type 1.
The use of a stainless-steel, press-fit mounted diaphragm guarantees both robustness and corrosion resistance. The microphone is fitted with a removable protection grid. It does not need an external polarization voltage, thus eliminating the need for cumbersome high-voltage DC supplies and at the same time enabling the use of inexpensive 2-wire system (CCLD) input.
The microphone is rear-vented in order to balance out the static pressure; the venting also determines the lower limiting frequency. Type 4950 comes with a calibration chart showing typical frequency response and individual sensitivity value.
Capacitance: 12.5 pF
Dynamic range: 15 – 142 dB
Frequency range: 6.5 – 16000 Hz
Inherent noise: 15 dB A
Lower limiting frequency -3dB: 5 Hz
Optimised: Free field
Polarization voltages: V
Pressure coefficient: -0.02 dB/kPa
Sensitivity: 50 mV/Pa
Temperature coefficient: 0.005 db/ºC
Temperature range: -30 – 100 C
Sound field: Free-field
Microphone type: Free field