M 657
- 1/4inch, pressure-field, 20kHz
The M 657 is a 1/4-inch pre-polarized pressure-field measurement microphone designed for ultra-high sound pressure level measurement, explosion sound pressure level measurement, and similar applications.
All microphones undergo rigorous environmental aging tests, providing them with 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
Specifications
| Parameter | Value |
|---|---|
| Dimensions | 1/4inch |
| Sound Field Type | Pressure field |
| Polarization Voltage | 0V(Pre-polarized) |
| Frequency Response | 5Hz – 20kHz ± 2dB |
| Dynamic Range | 62dB(A)-175dB |
| Noise Floor | 62dB(A) |
| Sensitivity | 0.25mV/Pa (-72dB± 3dB) re 1V/Pa |
| Standard | IEC 61094-4 type,WS3P |
| Typical Capacitance | 6.0pF |
| Pressure Equalization Method | Post-equalization |
| Operating Temperature | -20℃ ~ 60℃ |
| Temperature Coefficient | / |
| Humidity Coefficient | / |
| Relative Humidity | 20% - 90% no condensation |
| Static Pressure Coefficient | / |
Specifications
Humidity coefficient
Types of Acoustic Fields | Pressure Field |
Sensitivity mV/Pa(dBV/Pa) | 0.25mV/Pa (-72dB ± 3dB) re 1V/Pa |
Frequency range | 5Hz-20kHz ±2dB |
Dynamic range | 62dBA - 175dB |
Background noise | <62dBA |
Typical capacitance | 6.0pF |
Operating temperature range | -20℃ to 60℃ |
Temperature coefficient | -20 to 60 °C; sound pressure level variation < -0.003 dB (at 250 Hz, reference temperature 23 °C) |
Humidity coefficient | 20% to 90% RH; sound pressure level variation < -0.003 dB (at 250 Hz, reference temperature 40 °C, reference RH 50%) |
| Storage conditions | Temperature: 25°C ± 5°C, Humidity: 50% ± 15% R H(ensures long-term stability of the sensor) |



