1/4-inchFree-field Microphone, Externally Polarized

Free-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.