Special microphones
Special microphones are often required for applications where there are particular requirements regarding the methods of measurements and configurations.
GRAS special microphones are categorized as
Freq range: 10 Hz to 20 kHz
Dyn range: 33 dB(A) to 135 dB
Sensitivity: 50 mV/Pa
GRAS 40PH-10 CCP Free-field Array Microphone
The GRAS 40PH-10 Array Microphone is a low-cost microphone for general purpose measurements in arrays and matrices.
Freq range: 10 Hz to 20 kHz
Dyn range: 33 dB(A) to 142 dB
Sensitivity: 9 mV/Pa
GRAS 40PL-10 CCP Free-field Array Microphone, High Pressure
The GRAS 40PL-10 Array Microphone is a low-cost microphone for general purpose measurements in arrays and matrices. It has a wide useful frequency range reaching up to 20 kHz and a large dynamic range topping at 147 dB.
Freq range: 10 Hz to 20 kHz
Dyn range: 33 dB(A) to 142 dB
Sensitivity: 9 mV/Pa
GRAS 40PL-11 Short CCP Free-field Array Microphone, High Pressure
The GRAS 40PL-11 Array Microphone is a low-cost microphone for general purpose measurements in arrays and matrices. It has a wide useful frequency range reaching up to 20 kHz and a large dynamic range topping at 147 dB peak.
Freq range: 3.15 Hz to 10 kHz
Dyn range: 18 dB(A) to 138 dB
Sensitivity: 50 mV/Pa
GRAS 47AD 1/2'' CCP Flush-mount Microphone Set, High Sensitivity
The GRAS 47AD 1/2" CCP Flush-Mount Microphone Set is a low profile 1/2" precision pressure microphone with built-in CCP preamplifier. It's identical to the GRAS 47AX but differ in specifications.
Freq range: 3.15 Hz to 20 kHz
Dyn range: 22 dB(A) to 150 dB
Sensitivity: 12.5 mV/Pa
GRAS 47AX 1/2'' CCP Flush-mount Microphone Set
The GRAS 47AX 1/2" CCP Flush-Mount Microphone Set is a low profile 1/2" precision pressure microphone with built-in CCP preamplifier.
Freq range: 3.15 Hz to 60 kHz
Dyn range: 60 dB(A) to 184 dB
Sensitivity: 0.23 mV/Pa
GRAS 47BG-FV 1/4" CCP Miniature Flush-mount Microphone set, High Pressure
The GRAS 47BG-FV is a front-vented ¼″ CCP pressure microphone set for measuring very high sound pressure levels using flush mounting and where mounting space is limited or restrictive.
Freq range: 4 Hz to 70 kHz
Dyn range: 44 dB(A) to 166 dB
Sensitivity: 1.6 mV/Pa
GRAS 47BX 1/4" CCP Flush-mount Microphone Set
The GRAS 47BX 1/4" CCP Flush-Mounted Microphone Set is a low profile 1/4" precision pressure microphone with built-in CCP preamplifier.
Freq range (±3 dB): 0.5 Hz to 20 kHz
Dyn range: 17 dB(A) to 149 dB
Sensitivity: 50 mV/Pa
Use: For low frequency acoustic diagnostics
GRAS 46AN 1/2'' LEMO Free-field Standard Microphone Set, Low Frequency
The GRAS 46AN is a 1/2" Traditional Power (LEMO) free-field microphone set for measuring medium sound pressure levels at low frequencies. It is terminated with a 7-pin LEMO connector and is TEDS compatible. The equivalent Constant Current Power (CCP) type is GRAS 46AZ.
Freq range: 0.5 Hz to 20 kHz
Dyn range: 14 dBA to 149 dB
Sensitivity: 50 mV/Pa
GRAS 40AN 1/2" Ext. Polarized Free-field Microphone, Low Frequency
The 40AN is an IEC 61094 WS2F classified ½” externally polarized free-field, low-frequency microphone with rear-venting. The prepolarized equivalent is GRAS 40AZ.
Freq range: 0.5 Hz to 20 kHz
Dyn range: 14 dB(A) to 148 dB
Sensitivity: 50 mV/Pa
GRAS 40AZ 1/2" Prepolarized Free-field Microphone, Low Frequency
The 40AZ is a prepolarized free-field microphone with a large dynamic range and a wide frequency response. Its externally polarized equivalent is GRAS 40AN.
Freq range (±3 dB): 0.5 Hz to 20 kHz
Dyn range: 17 dB(A) to 138 dB
Sensitivity: 50 mV/Pa
Use: For low frequency acoustic diagnostics
GRAS 46AZ 1/2'' CCP Free-field Standard Microphone Set, Low Frequency
The GRAS 46AZ is a 1/2" Constant Current Power (CCP) free-field microphone set for measuring medium sound pressure levels at low frequencies. It is terminated with a BNC connector and is TEDS compatible. The equivalent traditional 200 V (LEMO) type is GRAS 46AN.
Freq range: 0.09 Hz to 20 kHz
Dyn range: 20 dB(A) to 148 dB
Sensitivity: 8 mV/Pa
GRAS 47AC 1/2" CCP Infra-Sound Microphone Set
The GRAS 47AC is a 1/2" CCP free-field microphone set optimized for infra-sound measurements down to 0.09 Hz.
Freq response: IEC 61043
Dyn range: 20 dB(A) to 157 dB
Sensitivity: 25 mV/Pa
GRAS 40AI 1/2" Ext. Polarized Intensity Microphone Pair
The 40AI is an IEC 61094-compliant, WS2F ½" externally polarized sound-intensity microphone pair especially suited for sound-intensity and sound-power measurements, sound-source location and IEC 61043 Standard Instrumentation. Its equivalent prepolarized version is GRAS 40GI
Freq response: IEC 61043
Dyn range: 20 dB(A) to 157 dB
Sensitivity: 25 mV/Pa
GRAS 40AK 1/2" Ext. Polarized Intensity Microphone Kit
The 40AK is an IEC 61094-compliant, WS2F ½" externally polarized sound-intensity microphone set. The microphones in the set are two 40AI microphones - two phase-matched free-field condenser microphones with extremely well-controlled phase characteristics for use in sound-intensity probes. This microphone pair has a free-field frequency response that complies with IEC 61043 1993 Class 1 and IEC 60651 Type 1 in the range from 20 Hz to 10 kHz.
Freq response: IEC 61043
Dyn range: 35 dB(A) to 172 dB
Sensitivity: 4 mV/Pa
GRAS 40BI 1/4" Ext. Polarized Intensity Microphone Kit
The 40BI is an IEC 61094-compliant, WS3F ¼" externally polarized sound-intensity microphone pair. The 40BI microphone pair consists of two phase-matched free-field condenser microphones with extremely well-controlled phase characteristics for use in sound-intensity probes. Their standard mounting threads make them compatible with all the usual available makes of measurement-microphone preamplifiers.
Freq response: IEC 61043
Dyn range: 27 dB(A) to 163 dB
Sensitivity: 12.5 mV/Pa
GRAS 40GI 1/2" Prepolarized Intensity Microphone Pair
The 40GI is an IEC 61043-compliant prepolarized sound-intensity microphone pair. Its externally polarized equivalent is GRAS 40AI.
Freq response: IEC 61043
Dyn range: 27 dB(A) to 163 dB
Sensitivity: 12.5 mV/Pa
GRAS 40GK 1/2" Prepolarized Intensity Microphone Kit
The 40GK is an IEC 61094-compliant, WS2F ½" prepolarized sound-intensity microphone set. The microphones in the set are two 40GI microphones - two phase-matched free-field condenser microphones with extremely well-controlled phase characteristics for use in sound-intensity probes. This microphone pair has a free-field frequency response that complies with IEC 61043 1993 Class 1 and IEC 60651 Type 1 in the range from 20 Hz to 10 kHz.
Freq range: Ref. IEC 61043 Class 1
Dyn range: 25 dB(A) to 152 dB
Sensitivity: 25 mV/Pa
GRAS 50AI-B 1/2" LEMO Intensity Probe
The GRAS 50AI-B Sound-intensity Probe builds on more than 20 years of theory and practical experience in sound-intensity measurements. It is adjustable, durable and fully complies with the requirements in IEC 61043, Electroacoustics- Instruments for the Measurement of Sound Intensity- Measurements with Pairs of Pressure Sensing Microphones, 1993 for Class 1 Sound-intensity probes.
Freq range: Ref. IEC 61043 Class 1
Dyn range: 25 dB(A) to 152 dB
Sensitivity: 25 mV/Pa
GRAS 50AI-C 1/2" LEMO Intensity Probe
The GRAS 50AI-C Sound-intensity Probe builds on more than 20 years of theory and practical experience in sound-intensity measurements. It is adjustable, durable and fully complies with the requirements in IEC 61043, Electroacoustics- Instruments for the Measurement of Sound Intensity- Measurements with Pairs of Pressure Sensing Microphones, 1993 for Class 1 Sound-intensity probes.
Freq range: Ref. IEC 61043 Class 1
Dyn range: 25 dB(A) to 152 dB
Sensitivity: 25 mV/Pa
GRAS 50AI-D 1/2" LEMO Intensity Probe
The GRAS 50AI-D Sound-intensity Probe builds on more than 20 years of theory and practical experience in sound-intensity measurements. It is adjustable, durable and fully complies with the requirements in IEC 61043, Electroacoustics- Instruments for the Measurement of Sound Intensity- Measurements with Pairs of Pressure Sensing Microphones, 1993 for Class 1 Sound-intensity probes.
Freq range: Ref. IEC 61043 Class 1
Dyn range: 25 dB(A) to 152 dB
Sensitivity: 12.5 mV/Pa
GRAS 50AI-L 1/2" CCP Intensity Probe
The GRAS 50AI-L 1/2" CCP Intensity Probe is a general purpose sound intensity probe with remote control and direct connection to LMS data acquisition modules with ICP inputs.
Freq range: IEC 61043 Class 1
Dyn range: 25 dB(A) to 152 dB
Sensitivity: 12.5 mV/Pa
GRAS 50AI-LP 1/2" CCP Rugged Intensity Probe
The GRAS 50AI-LP 1/2" CCP Rugged Intensity Probe is an industrial sound intensity probe in a very robust design that makes it suitable for use in heavy industrial environment. The probe has remote control and direct connection to LMS data acquisition modules with ICP inputs.
Freq range: Ref. IEC 61043 Class 1
Dyn range: 27 dB(A) to 146
Sensitivity: 12.5 mV/Pa
GRAS 50GI CCP Intensity Probe
GRAS 50GI is a sound intensity probe for direct connection to signal analyzers or data acqusition devices with IEPE inputs. The probe includes a pair of phase-matched prepolarized precision microphones which meet the requirements in IEC standard 61043 for a class-1 intensity probe. The small rugged 1/4" CCP preamplifiers ensure minimum disturbances to the sound field for accurate measurements in the full frequency range.
Freq range: IEC 61043 Class 1
Dyn range: 27 dB(A) to 146 dB
Sensitivity: 12.5 mV/Pa
GRAS 50GI-P CCP Rugged Intensity Probe
Type 50GI-P is a sound intensity probe for direct connection to signal analyzers or data acqusition devices with IEPE inputs. The probe includes a pair of phase-matched prepolarized precision microphones which meet the requirements in IEC standard 61043 for a class-1 intensity probe.
Freq range: IEC 61043 Class 1
Dyn range: 27 dB(A) to 146 dB
Sensitivity: 12.5 mV/pa
GRAS 50GI-R CCP Intensity Probe with Remote Control
The 50GI-R is a sound intensity probe for direct connection to signal analyzers or data acquisition devices with IEPE inputs. The probe includes a pair of phase-matched prepolarized precision microphones which meet the requirements in IEC standard 61043 for a class-1 intensity probe. The small rugged ¼" CCP preamplifiers ensure minimum disturbances to the sound field for accurate measurements in the full frequency range.
Freq range: IEC 61043 Class 1
Dyn range: 27 dB(A) to 146 dB
Sensitivity: 12.5 mV/Pa
GRAS 50GI-RP CCP Rugged Intensity Probe
Type 50GI-RP is a sound intensity probe for direct connection to signal analyzers or data acqusition devices with IEPE inputs. The probe includes a pair of phase-matched prepolarized precision microphones which meet the requirements in IEC standard 61043 for a class-1 intensity probe..
Freq range: IEC 61043 Class 1
Dyn range: 25 dB(A) to 152 dB
Sensitivity: 25 mV/Pa
GRAS 50VI-1 Vector intensity probe
The GRAS 50VI-1 Vector Intensity Probe is a flexible and adjustable, two or three-dimensional sound-intensity probe. The probe handle has marked inputs for 3 pairs of preamplifiers (a pair for each of the mutually-perpendicular directions) and a 24-pin LEMO output socket at its base for connecting it to a suitable Power Module (e.g. Type 12AC) or Power Modules (via cable adapter).
Freq range: 10 Hz to 10 kHz
Dyn range: -2 dB(A) to 110 dB
Sensitivity: 1.1 V/Pa
GRAS 40HF 1'' Lownoise Microphone System
The GRAS 40HF 1-inch Lownoise Microphone System 40HF can measure sound pressure levels well below the threshold of human hearing; and is amply suitable for use in sound-power measurements on even very quiet products. Its very wide dynamic range permits measurements down to below – 10 dB re. 20 μPa (in 1/3-octave bands) from 20 Hz to 10 kHz.
Freq range: 10 Hz to 16 kHz
Dyn range: 6.5 dB(A) to 113 dB
Sensitivity: 800 mV/Pa
GRAS 40HH 1/2'' Lownoise Microphone System
The GRAS 40HH 1/2" Lownoise Microphone System can measure sound pressure levels down to close to the threshold of human hearing; and is amply suitable for use in sound-power measurements on even very quiet products. Its very wide dynamic range permits measurements down to 6.5 dB re. 20 μPa (in 1/3-octave bands) from 20 Hz to 20 kHz.
Freq range: 10 Hz to 16 kHz
Dyn range: 6.5 dB(A) to 110 dB
Sensitivity: 850 mV/Pa
GRAS 40HL 1/2'' LEMO Low-noise Microphone System
The GRAS 40HL 1/2" Low-noise Microphone System measures sound pressure levels down close to the threshold of human hearing. It is thus generally suitable for sound-power measurements on even very quiet products. Its very wide dynamic range permits measurements down to 6.5 dB re. 20 μPa (in 1/3-octave bands) from 20 Hz to 20 kHz.
Freq range: 10 Hz to 16 kHz
Dyn range: 6.5 dB(A) to 113 dB
Sensitivity: 800 mV/Pa
GRAS 40HT 1/2'' Lownoise Microphone System for Confined Spaces
The GRAS 40HT ½-inch Lownoise Microphone System for Confined Spaces has specifications similar to GRAS 40HH but is designed for little space applications.
Freq range: 10 Hz to 20 kHz
Dyn range: 6.5 dB(A) to 100 dB SPL (20 Hz - 8 kHz)
6.5 dB(A) to 85 dB SPL (8 kHz - 20 kHz)
Sensitivity: 400 mV/Pa
GRAS 47HC 1/2'' CCP Low-noise Microphone System
The GRAS 47HC ½" Low-noise Microphone System measures sound pressure levels down to close to the threshold of human hearing. It is thus generally suitable for sound-power measurements on even very quiet products. Its very wide dynamic range permits measurements down to below 6.5 dB re. 20 μPa (in 1/3-octave bands).
Standard: IEC 61672-1
TEDS
Special features: Configurable for 90 or 0 degrees of incidence
IP55 proof
GRAS 41AC-3 CCP Outdoor Microphone for Community & Airport Noise
The 41AC-3 is a SysCheck2™ enabled outdoor microphone for unattended use for prolonged periods of time. It can be used for community noise applications or for monitoring of overhead aircraft noise.
Standard: IEC 61672-1
Configurable for 90 or 0 degrees of incidence
IP55 proof
GRAS 41AC-4 LEMO Outdoor Microphone for Community and Airport Noise (0 V pol.)
The 41AC-4 is an outdoor microphone for unattended use for a prolonged period of time. It can be used for community noise applications or for monitoring of overhead aircraft noise.
Dyn range: 20 dB(A) to 156 dB
Sensitivity: 50 mV/Pa
0° incidence (airport noise)
GRAS 41AM Permanent Outdoor Microphone System for airport noise
The GRAS 41AM Outdoor Microphone System is for outdoor use whenever trouble-free acoustic measurements and, in particular, noise monitoring around airports are required.
Dyn response: 20 to 156
Sensitivity: 50 mV/Pa
90° incidence (community noise)
GRAS 41CN Permanent Outdoor Microphone System for community noise
GRAS 41CN Permanent Outdoor Microphone System for community noise
Freq range: 3.15 Hz to 20 kHz
Dyn range: 22 dB(A) to 150 dB
Sensitivity: 12.5 mV/Pa
GRAS 67AX ø400 mm CCP Ground Array Microphone Kit
The GRAS 67AX ½" CCP Ground Array Microphone Set consists of a ½” precision pressure microphone with built-in CCP preamplifier, a ø400 mm mounting plate, and an adapter for a BNC cable.
Freq range: 2 Hz to 8 kHz
Dyn range: 40 dB(A) to 166 dB
Sensitivity: 3 mV/Pa
GRAS 40SA Probe Microphone
The GRAS 40SA Probe Microphone is a small, compact unit for sound-pressure measurements in small enclosures, in harsh environments and in very close proximity to sound sources. The high acoustic input impedance at the tip of the probe minimizes its influence on the acoustic field, while the stainless-steel tube of the probe can withstand temperatures of up to 800 ºC.
Freq range: 2 Hz to 8 kHz
Dyn range: 40 dB to 160 dB
Sensitivity: 3 mV/Pa
GRAS 40SC CCP Probe Microphone
The CCP Probe Microphone 40SC is a small, constant-current powered, compact unit for sound-pressure measurements in small enclosures, in harsh environments and in very close proximity to sound sources. The high acoustic input impedance at the tip of the probe minimizes its influence on the acoustic field, while the stainless-steel tube of the probe can withstand temperatures of up to 800 ºC.
Freq range: 10 Hz to 20 kHz
Dyn range: 52 dB(A) to 174 dB
GRAS 67SB Blast Probe Microphone according to ANSI S12.42
The GRAS 67SB Blast Probe is designed as a reference microphone for impulse measurements according to the ANSI/ASA S12.42 standard.
Freq range: 5 Hz to 70 kHz
Dyn range: 56 dB(A) to 178 dB
Sensitivity: 0.5 mV/Pa
GRAS 40LA 1/4" CCP Precision Surface Microphone, High Pressure
The GRAS 40LA High-Precision Surface Microphone is a high-precision microphone for measurements on planar and curved surfaces. It has a wide useful frequency range reaching up to 70 kHz and a large dynamic range topping at around 178 dB.
Freq range: 5 Hz to 70 kHz
Dyn range: 46 dB(A) to 167 dB
Sensitivity: 1.8 mV/Pa
GRAS 40LS 1/4" CCP Precision Surface Microphone
The GRAS 40LS High-Precision Surface Microphone is a high-precision microphone for measurements on planar and curved surfaces. It has a wide useful frequency range reaching up to 70 kHz and a large dynamic range topping at around 167 dB.
Freq range: 10 Hz to 12 kHz
Dyn range: 27 dB(A) to 145 dB
Sensitivity: 15 mV/Pa
GRAS 40PS-1 CCP Surface Microphone
The GRAS Surface Microphone 40PS-1 is a low-profile, light surface microphone for general purpose measurements on planar and curved surfaces exposed to slipstreams.
Turb. att.: Up to 25 dB*
Turb. speed: Up to Mach 0.2
Freq. range (turbulence) 500 Hz - 10 kHz*
Acoustic att.: Less than 3 dB
Directivity: ± 60 Deg *Depending on flow-speed
GRAS 67TS Turbulence Screen Kit
The GRAS 67TS Turbulence Screen Kit is designed for aeroacoustic testing in solid-walled wind tunnels. The hydrodynamic component of turbulence is attenuated up to 25 dB. Thereby the acoustic signals of interest can be identified and diagnosed with a reliable resolution.
Turb. att.: Up to 25 dB*
Turb. speed: Up to Mach 0.2
Turb. suppr. freq. range: 500 Hz - 10 kHz*
Acoustic att.: Less than 3 dB
Directivity: ± 60 Deg
Freq. range (acoustic) 100 Hz - 70 kHz
Dyn.range 44 dB(A) - 166 dB *Depending on flow-speed
GRAS 67TS-1-CL Turbulence Screen Kit with Flush-mount Microphone
The GRAS 67TS-1-CL Turbulence Screen Kit is designed for aeroacoustic testing in solid-walled wind tunnels. The hydrodynamic component of turbulence is attenuated up to 25 dB. Thereby the acoustic signals of interest can be identified and diagnosed with a reliable resolution.
Freq range: 20 Hz to 20 kHz (±1 dB)
16 Hz to 31.5 kHz (±3 dB)
Dyn range: 64 dB(A) to 184 dB
Sensitivity: 0.12 mV/Pa (±2 dB)
Use: For aeroacoustic measurements
GRAS 48LA UTP Microphone, High Pressure
48LA is an Ultra-thin Precision (UTP) surface microphone for aeroacoustic testing. It is a low-profile ¼″ CCP high-pressure condenser microphone. The microphone is only 1 mm high and can, therefore, be mounted in air flow without disturbing the sound field.
Freq range: 20 Hz to 31.5 kHz (±1 dB)
10 Hz to 50 kHz (±3 dB)
Dyn range: 54 dB(A) to 170 dB
Sensitivity: 0.6 mV/Pa (±3 dB)
Use: For aeroacoustic measurements
GRAS 48LX-1 UTP Microphone, Medium Pressure
48LX-1 is an Ultra-thin Precision (UTP) surface microphone for aeroacoustic testing. It is a low-profile ¼″ CCP medium-pressure condenser microphone. The microphone is only 1 mm high and can, therefore, be mounted in air flow without disturbing the sound field.