The acoustic array measurement system, commonly known as the acoustic camera, is composed of multiple microphones arranged according to a certain rule, and the sound pressure level distribution on a plane or spherical surface is generated by the array signal processing algorithm (such as beam-forming, acoustic holography).
The sound visualization is realized by means of graphs, and the noise source distribution of the measured object is displayed by means of photos or videos.
Acoustic array system is widely used in noise source location, wind tunnel noise testing and machine condition monitoring.
Acoustic array systems usually require dozens, or even hundreds of microphones.
BSWA provides high-performance, economical array microphones for the research and development of acoustic array systems.
Let’s talk about how to choose the right microphone for your array.
MI19
Class 1 | in accordance with IEC 61672 |
|---|---|
Transducer type | Electrete pressure transducer |
Diameter | 1/4″ |
Polar pattern | Omni |
Frequency range | 20 Hz – 20 kHz |
Sensitivity @ 1 kHz | 50 mV/Pa ± 0.5 dB |
Max. SPL for 1% THD at 1 kHz | 130 dB Peak |
Inherent noise | 30 dB(A) |
Output impedance | <50 Ohm |
Current consumption | 2-6 mA |
Power supply | 18 V DC to 30 V DC |
Bias: | 12.5 Volt |
Temperature range, operation | -20°C to +80°C |
Heat resistant | up to 110 °C |
Diameter | 7 mm ± 0.05 mm |
Length | 83 mm 1/4″ sleeve diameter over the entire length |
Weight | 19 g |
Connector | BNC (fem.) |
Model | 1/4″ IEPE Microphones | Price |
|---|---|---|
 | ROGA Instruments products are free from planned obsolescence, technically accessible, durable and repairable. | |
POM-MI1921 | MI19 and MI21 microphone sleeve adapter from 1/4″ inner diameter to 1/2″ outer diameter. POM material to ensure galvanic isolation to prevent ground and earth loops | 24 $ |
POM-MI17RG50 | MI17 and RG-50 microphone sleeve adapter to 1/2″ outer diameter. POM material to ensure galvanic isolation to prevent ground and ground loops | 24 $ |
MicCAL | Microphone Calibration Fee for ROGA Instruments microphones MI15 | MI17 | MI18 | MI19 | MI21| RG-50 | MP30| MP40 After successful factory calibration, the microphone is returned to the customer with our factory calibration certificate. | 155 $ |
MicREP | Microphone Repair Fee for ROGA Instruments microphones MI15 | MI17 | MI18 | MI19 | MI21| RG-50 After successful repair and factory calibration, the microphone is returned to the customer with our factory calibration certificate. | 225 $ |
WS-RG-40 | 1/4″ microphone windscreen Ø 40 mm | 38 $ |
MI19 | MI19; ¼” electret microphone for industrial applications Sensitivity 50 mV/Pa Constant current supply 2-8 mA BNC connector Polar pattern: omnidirectional Class 1 frequency response in accordance with IEC 61672 20 Hz – 20 kHz calibration sheet included Sensitivity & Frequency Response Inherent noise 27 dBA SPL Max 130 dB HS Code 85181000 | 385 $ |
MI19SW | IP55 splash water resistant ¼” electret microphone for industrial applications Sensitivity 50 mV/Pa Constant current supply 2-8 mA BNC connector Polar pattern: omnidirectional Class 1 frequency response in accordance with IEC 61672 20 Hz – 20 kHz calibration sheet included Sensitivity & Frequency Response Inherent noise 27 dBA SPL Max 130 dB HS Code 85181000 | 455 $ |
RG-50HL | High SPL Microphone e.g. shooting noise WS3F Free-field IEC 61094-5 Total length: 95 mm Sensitivity 10 mV/Pa constant current Supply 2-20 mA BNC connection Polar pattern: omnidirectional Frequency response: 5 Hz – 4 kHz: ± 1 dB 4 kHz – 30 kHz: ± 1.5 dB factory calibration certificate included measuring range up to SPL 144 dBRMS / 150 dB peak HS Code 85181000 | 1275 $ |
MK342 E + MV310 Set | 1/4″ microphone with constant pressure frequency response WS3P according to IEC 61094-4 Pressure 3.5Hz to 70kHz 60dB(A) to 186dB pre-polarized HS Code 85181000 | 1480 $ |
MI21 | MI21; ¼” electret condenser microphone Splash Water Proof IP55 Sensitivity 50 mV/Pa / ± 1.0 dB CCP IEPE supply 2-6 mA BNC connector Polar pattern: omnidirectional Frequency response IEC 61094-5 20 Hz – 4 kHz: ± 0.5 dB 4 kHz – 20 kHz: ± 1.5 dB corresponds to class 1 Calibration sheet included Sensitivity & Frequency Response Inherent noise 26 dB(A) SPL Max 130 dB HS Code 85181000 | 588 $ |
MI17 | MI17; 1/4″ IEPE microphone, Sensitivity 50 mV/Pa, constant current supply 2-8 mA BNC connection Frequency response: Class 1 – IEC 61094-5 20 Hz – 4 kHz: ± 0.5 dB 4 kHz – 20 kHz: ± 1.5 dB free field, corresponds to class 1 including individual Calibration sheet (sensitivity & frequency response) Inherent Noise 26 dB (A) Download MI17 PDF HS Code 85181000 | 543 $
|
MI17SW | MI 17SW; 1/4″ IEPE microphone Splash Water Proof IP55 Sensitivity 50 mV/Pa, constant current supply 2-8 mA BNC connection Frequency response: 20 Hz – 4 kHz: ± 0.5 dB 4 kHz – 20 kHz: ± 1.5 dB free field, corresponds to class 1 IEC 61094-5 including individual Calibration sheet (sensitivity & frequency response) Inherent Noise 26 dB (A) HS Code 85181000 | 588 $
|
RG-50 | RG-50; 1/4″ IEPE free field microphone Sensitivity 50 mV/Pa constant current supply 2- 20mA BNC connection Frequency response 5 Hz – 4 kHz: ± 0.5 dB 4 kHz – 30 kHz: ± 1.5 dB free field, corresponds to class 1 IEC 61094-5 including individual Calibration sheet (sensitivity & frequency response) Inherent Noise 26 dB (A) HS Code 85181000 | 543 $ |
RG-50SW | RG-50SW; 1/4″ IEPE Free-field microphone Sensitivity 50 mV / Pa constant current supply 2- 20mA BNC connection Splash Water Proof IP55 Frequency response 5 Hz – 4 kHz: ± 0.5 dB 4 kHz – 30 kHz: ± 1.5 dB free field, corresponds to class 1 IEC 61094-5 including individual Calibration sheet (sensitivity & frequency response) Inherent Noise 26 dB (A) HS Code 85181000 | 588 $ |
Key points for choosing the array microphone
1, Dynamic Range
ROGA has three array microphones, RG-50, MPA416, MPA436A and MPA456, which cover the measurement range from 29dBA to 151dB. However, the sound pressure measurement range of each model is different, customers will need to choose the appropriate model according to the applications.
For example, RG-50 & MPA416 is suitable for conventional acoustic array testing.
MPA436A is suitable for high dynamic range acoustic testing, MPA456 is an array microphone designed for high sound pressure and acoustic wind tunnel.
RG-50 Frequency Response
2, Frequency Response
The MI17, MPA416 and MPA436A have the frequency range from 20 Hz to 20 kHz.
They are suitable for the most applications in noise measurements. The MPA456 has good performance in high frequencies up to 32 kHz.
It is suitable for conditioning monitoring using acoustic array technologies.
3, Phase matching
The phase difference between the microphones are required to be small enough to ensure the accuracy of measurements.
Regardless of the algorithm or the array shape, all calculations and delays are based on the premise that the microphone time differences are highly consistent.
That is, the phases are highly consistent.
ROGA array microphones are strictly phase matched before ex-factory inspection, and the phase difference of a batch of microphones is controlled within ±5 degrees up to 5000 Hz.
