4950  1/2-inch Free-field Microphone, 8 Hz to 16 kHz, Prepolarized

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 construction of Type 4950 makes it the ideal choice for cost-effective, portable instruments intended for use under different conditions including humid and polluted atmospheres.

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 (DeltaTron®) 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.