PLACID measurement microphones overview

Accurate and Stable measurement microphones

According to different application scenarios, measurement sensors can be divided into three groups: free field, pressure field and random field. The fundamental difference between these three groups of sensors is that at high frequencies, the test wavelength is similar to the sensor size, and the presence of the sensor will affect the sound field.

FREE FIELD SENSOR

The free field sensor actually measures the sound pressure value when the sensor is not in the sound field. At high frequencies, the sensor itself can affect the sound pressure test. This type of sensor has been designed with compensation for its effect on the sound field.

For most sound pressure tests, we choose free-field microphones, which are used in sound level meters, sound power, and radiation studies.

PRESSURE FIELD SENSOR

The pressure field microphone measures the sound pressure on the sensor diaphragm. Practical applications are in closed coupling cavities, or in walls and solid boundaries. In this case, the sensor forms part of the wall and the measured sound pressure is also the value of the sound pressure on the wall.

RANDOM FIELD SENSOR

Random field sensors are used to test sound fields with sound from different sources, like reverberation chambers or other highly reflective fields. The effect of sound from different directions on the sensor depends on how these sound waves are distributed. For a test sensor, its distribution standard has been defined statistically. According to ANSI standards, random field sensors are often used in sound pressure level testing.

Discover a wide selections of our measurement microphones according to your sound measurement needs

Click on the product name below for more info!

Type

Diameter (Inch)

Sound Field

Frequency (Hz ~ kHz)

Sensitivity (mV/Pa)

Dynamic Range (dBA)

Polarization Voltage (V)

Height (mm)

IEC 61094 Designation

1/2 “

Free 

20 ~ 20 

40

17 – 150

200

17.6

WS2F Class I

1/2 “

Pressure 

20 ~ 20 

12

27 – 155

200

12.3

WS2P Class I

1/2 “

Free 

20 ~ 20 

12

27 – 155

0

12.3

WS2F Class I

1/2 “

Free 

20 ~ 20 

50

17 – 146

0

17.6

WS2F Class I

1/2 “

Free 

20 ~ 20

32

22 – 130

0

17.6

WS2F Class II

1/2 “

Pressure 

20 ~ 20

12

27 – 155 

0

12.3

WS2P Class I

1/4 “

Free 

20 ~ 20

50

29 – 126

0

5.0

WS3F Class II

1/4 “

Free 

20 ~ 40

4

34 – 164

0

5.0

WS3F Class I

1/4 “

Free 

20 ~ 16 

4

34 – 164

0

7.0

WS3F Class I

1/4 “

Free 

20 ~ 16 

8

30- 126

0

7.0

WS3F Class II

X