GRAS 40BE-FV 1/4" Prepolarized Free-Field Microphone, Front Vented

Freq range: 4 Hz to 80 kHz
Dyn range: 30 dB(A) to 168 dB
Sensitivity: 4 mV/Pa

Technology

Introduction

It is a high-precision condenser microphone made according to IEC 61094-4 requirements. Its dynamic range makes it suitable for high-frequency or high-level measurements, as well as acoustic transient measurements. It is extremely robust and reliable and can measure sound pressure levels up to 168 dB in the range of 4 Hz to 100 kHz.

40BE-FV is individually factory-calibrated and delivered with a calibration chart stating its specific open-circuit sensitivity and pressure frequency response. 

Typical applications and use

The 40BE-FV is ideal for sound measurements at very high frequencies and levels, as well as acoustic transient measurements. It is suitable for general purpose measurements in open acoustic fields. 

Compatibility

The 40BE-FV requires a standardized 1/2" or 1/4" CCP preamplifier and an input module that supports this technology with a BNC, SMB, or Microdot connector.

System verification

For daily verification and check of your measurement setup, we recommend using a calibrator like GRAS 42AG Sound Level Calibrator. 

For proper sensitivity calibration, we recommend using a pistonphone like GRAS 42AP Intelligent Pistonphone. 

Quality and warranty

All GRAS microphones are made of high-quality materials that will ensure life-long stability and robustness. The microphones are all assembled in verified clean-room environments by skilled and dedicated operators with many years of expertise in this field.

The microphone diaphragm, body, and improved protection grid are made of high-grade stainless steel, which makes the microphone resistant to physical damage, as well as corrosion caused by aggressive air or gasses.

This, combined with the reinforced gold-plated microphone terminal which guarantees a highly reliable connection, enables GRAS to offer 5 years warranty against defective materials and workmanship.

Service

If you accidentally damage the diaphragm on a GRAS microphone, we can—in most cases—replace it at a very reasonable cost and with a short turn-around time. This not only protects your investment, but also pleases your quality assurance department because you don’t have to worry about new serial numbers, etc.

Calibration

Before leaving the factory, all GRAS microphones are calibrated in a controlled laboratory environment using traceable calibration equipment.

Depending on the use, measurement environment, and internal quality control programs, we recommend recalibrating the microphone at least once a year.

Specifications

Coupler volume
mm³
0.4 ccm
Frequency range (±1 dB)
Hz
10 to 40 k
Frequency range (±2 dB)
Hz
4 to 80 k
Frequency range (±3 dB)
Hz
4 to 100 k
Dynamic range lower limit (microphone thermal noise)
dB(A)
30
Dynamic range lower limit with GRAS preamplifier
dB(A)
35
Dynamic range upper limit
dB
168
Dynamic range upper limit with GRAS preamplifier @ +28 V / ±14 V power supply
dB
164
Dynamic range upper limit with GRAS preamplifier @ +120 V / ±60 V power supply
dB
168
Dynamic range upper limit with GRAS CCP preamplifier
dB
160
Open-circuit sensitivity @ 250 Hz (±3 dB)
mV/Pa
4
Open-circuit sensitivity @ 250 Hz (±3 dB)
dB re 1V/Pa
-48
Resonance frequency
kHz
100
Microphone cartridge capacitance, typ.
pF
5
Microphone venting
Front
IEC 61094-4 Compliance
WS3F
Temperature range, operation
°C / °F
-40 to 120 / -40 to 248
Temperature range, storage
°C / °F
-40 to 85 / -40 to 185
Temperature coefficient @250 Hz
dB/°C / dB/°F
-0.01 / -0.006
Static pressure coefficient @250 Hz
dB/kPa
-0.013
Humidity range non condensing
% RH
0 to 100
Humidity coefficient @250 Hz
dB/% RH
-0.001
Influence of axial vibration @1 m/s²
dB re 20 µPa
60
CE/RoHS compliant/WEEE registered
Yes / Yes, Yes
Weight
g / oz
1.75 / 0.062
Specification Conditions

Typical frequency response (without protection grid). Upper curve shows free-field response for 0°, lower curve shows pressure response.

GRAS Sound & Vibration reserves the right to change specifications and accessories without notice.

Dimensions

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