4942 1/2-Inch Diffuse-Field Microphone
Prepolarized diffuse-field ½” microphone Type 4942 is optimised for general random-incidence measurements and for standardised noise measurements in accordance with ANSI standards. And being prepolarized it can connect to CCLD input conditioning.
- Diffuse-field measurements
- In-car measurements
- high humidity conditions
USE OF DIFFUSE-FIELD MICROPHONES
A diffuse-field microphone, also called a random-incidence microphone, is designed to have a flat response when signals arrive simultaneously from all directions. They should therefore not only be used for measurement in reverberation chambers, but in all situations where the sound field is diffuse, or where several sources contribute to the sound pressure at the measurement position. Practical examples are indoor situations, where the sound is reflected by walls, ceilings, and objects in the room, or measurements inside a car.
The microphone is capable of withstanding the IEC 68-2-32 1 metre drop test.
The sensitivity can be calibrated at 250 Hz by using Pistonphone Type 4228 with ½” Adaptor DP 0776. The actuator response can be measured using Actuator UA 0033. The random-incidence response can be obtained by adding the type-specific, random-incidence correction to the actuator response. Please note that this microphone is not suitable for pressure-field measurements.
Capacitance: 14 pF
Dynamic range: 14.6 – 146 dB
Frequency range: 6.3 – 16000 Hz
Inherent noise: 14.6 dB A
Lower limiting frequency -3dB: 4 Hz
Optimised: Diffuse Field
Polarization voltages: V
Pressure coefficient: -0.01 dB/kPa
Sensitivity: 50 mV/Pa
Temperature coefficient: -0.006 db/ºC
Temperature range: -40 – 150 C
Sound field: Diffuse-field
Microphone type: Diffuse Field