Placid Random Incidence Microphone

Accurate and Stable measurement microphones




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!


Diameter (Inch)

Sound Field

Frequency (Hz ~ kHz)

Nominal Sensitivity (mV/Pa)

Dynamic Range (dBA)

Polarization Voltage (V)

Height (mm)

IEC 61094 Designation

1/2 “

Random Incidence

20 ~ 20


16 – 146



WS2F Class I


PLACID PMP25 Random Incidence Microphone



The PLACID PMP25 is a high-precision condenser microphone manufactured in compliance with the IEC 61094-4 requirements and classified as a Class 1 microphone.

The PMP25 microphone is optimized for pressure-field measurements.
As all PLACID microphones, the PMP25 comes with an individually calibration certificate.

Frequency response


Grid: Copper-nickel plating
Housing: Stainless Steel
Diaphragm: Nickel
Back Plate: Stainless Steel
Insulator: Crystal Quartz
Electret: Teflon



The PLACID PMP25 microphone requires a standardized 1/2″ BNC preamplifier that does not need to provide polarization.


The PMP25 is a robust and stable microphone and is being used as an all-round free field
microphone suitable for laboratory as well as field jobs.

Daily usage

PLACID recommends calibration before and after each measurement with a calibrator.

Individual calibration

All PLACID measurement microphones are being calibrated in a controlled laboratory environment using traceable calibration equipment complying with ISO17025 standards.
We recommend that all PLACID measurement microphones are re-calibrated every year to guarantee an optimized usage.
PLACID Traceable Calibration is performed by our qualified staff and under controlled conditions according to the procedures and standards such as ISO17025.


All PLACID measurement microphone sets are made of high-quality materials that will ensure long stability and durability.
The microphone diaphragm, body, and protection grid are made of high-grade stainless steel, which makes the microphone resistant to physical damage.
PLACID offers 2 years warranty against defective materials and workmanship.