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40AE 1/2" Prepolarized Free-Field Microphone
40AE 1/2" Prepolarized Free-Field Microphone
The GRAS 40AE is a 1/2" Prepolarized free-field microphone for measuring medium sound pressure levels at medium frequencies. The equivalent externally polarized 200 V type is GRAS 40AF.
GRAS 40AE is a high-precision electret condenser microphone made according to IEC 61094-4 requirements. The electret technology for microphones was introduced in the beginning of the 1960’s and has been continuously improved over the years. At GRAS, we have developed and refined our own techniques. This guarantees that our prepolarized microphones are as stable and robust as our traditional, externally polarized versions in daily use scenarios.
The 40AE’s design is based on the original reference ½” pressure microphone, but optimized for free-field measurements with a 12 dB increase of the sensitivity. The result is a nominal sensitivity of 50 mV/Pa, slightly longer microphone housing, and a natural reduced dynamic range.
Key Specifications
| Polarization/Connection | 0 V / CCP |
| Frequency range (±1 dB) | 5 Hz to 10 kHz |
| Frequency range (±2 dB) | 3.15 Hz to 20 kHz |
| Dynamic range lower limit (microphone thermal noise) | 15 dB(A) |
| Dynamic range lower limit with GRAS preamplifier | 17 dB(A) |
| Dynamic range upper limit | 148 dB |
| Dynamic range upper limit with GRAS preamplifier @ +28 V / ±14 V power supply | 142 dB |
| Dynamic range upper limit with GRAS preamplifier @ +120 V / ±60 V power supply | 148 dB |
| Dynamic range upper limit with GRAS preamplifier | 138 dB |
| Open-circuit sensitivity @ 250 Hz (±1.5 dB) | 50 mV/Pa |
| Open-circuit sensitivity @ 250 Hz (±1.5 dB) | -26,0 dB re 1V/Pa |
| Resonance frequency | 14 kHz |
| Microphone cartridge capacitance, typ. | 14 pF |
| Microphone venting | Rear |
| Temperature range, operation | -40 to 120 °C / -40 to 248 °F |
| IEC 61094-4 Designation | WS2F |
| Temperature range, storage | -40 to 85 °C / -40 to 185 °F |
| Temperature coefficient @250 Hz | -0.01 dB/°C / -0.006 dB/°F |
| Humidity range non condensing | 0 to 90 % RH |
| Static pressure coefficient @250 Hz | -0,014 dB/kPa |
| Humidity coefficient @250 Hz | -0,001 dB/% RH |
| Influence of axial vibration @1 m/s² | 62 dB re 20 µPa |
| Weight | 6.50 g / 0.229 oz |
Specifications from the official GRAS product sheet. Please refer to the attached datasheet for full details.
