HomeProductsSensorsMicrophone kit1/4inch, pressure-field, 20kHz

M 657+A 811

1/4inch, pressure-field, 20kHz
M 657+A 811 is a 1/4-inch pre-polarized pressure-field measurement microphone system, designed for ultra-high sound pressure level measurement, explosion sound pressure level measurement, and similar applications.
All microphones undergo rigorous environmental aging tests, providing advantages such as a wide frequency range, broad dynamic range, flat frequency response, and long-term stability. This enables the collection of acoustic source information across an ultra-wide frequency band.

Description
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Description

Specifications

Parameter	Value
TEDS Function	No
Dimensions	1/4inch
Sound Field Type	Pressure field
Polarization Voltage	/
Frequency Response	5Hz - 20kHz ±2dB
Dynamic Range	62dB（A）-175dB
Noise Floor	≤62dB（A）
Sensitivity mV/Pa (dBV/Pa)	0.25mV/Pa（-72dB ±3dB）
IEC 61094-4 Type	WS3P
Maximum Output Voltage	/
Output Impedance	/
Supply Power	/
Pressure Equalization Method	/
Connector Type	/
Operating Temperature	-20°C to 60°C
Temperature Coefficient	/
Humidity Coefficient	<0.1dB（20%- 90% no condensation）
Relative Humidity	20%- 90% no condensation
Static Pressure Coefficient	/

Specifications

Types of Acoustic Fields	Pressure Field
Sensitivity mV/Pa(dBV/Pa)	0.25mV/Pa（-72dB ±3dB）
Frequency range	5Hz-20KHz ±2dB
Dynamic range	62dBA- 175dB
Background noise	＜62dBA
Typical capacitance	6.0 pF
Temperature range	-20℃ - 60℃
Temperature coefficient	-20~60°C，ΔSPL < −0.003 dB (at 250 Hz, reference temperature: 23 °C)
Humidity coefficient	20% ~ 90% RH, ΔSPL < -0.003 dB (at 250 Hz, reference temperature 40°C, reference RH 50%)
Storage conditions	Temperature: 25 °C ±5 °C RH: 50% ±15% RH (for long-term stability)

Dimensions

657+811.png

The measuring microphones we produce are precision sensors, and all aspects related to production are strictly controlled, including material selection, production processes, testing control, and production environment.

图片1.png After years of continuous improvement, we now use special nickel alloy materials as the core material for the diaphragm. Compared to other alloy materials, it exhibits higher sensitivity, lower distortion rate, and more stable long-term performance. The front body of the microphone is made of stainless steel, ensuring that the entire microphone maintains extremely robust structural characteristics even under various assembly conditions.

We adopt advanced production processes and fully automated precision machining equipment, which significantly reduces the accuracy errors caused by secondary clamping in traditional machining equipment. This greatly enhances the dimensional consistency, geometric accuracy, and overall quality stability of the products, providing reliable technical support for demanding application scenarios.

At the same time, we employ extremely rigorous testing and control measures, conducting quantitative testing on any links that may lead to product quality issues, and implementing test sequence control to prevent skip-station situations. The comprehensive MES control enables all data to be traceable, ensuring a high degree of consistency in sensor quality.

The entire production process of all our microphones is strictly carried out in a dust-free workshop, which can minimize the amount of dust in the air, thus creating a stable and pure working environment for the sensors. This ensures a long and stable lifespan for the sensors and maintains their excellent performance throughout daily use.