OM226 Permanent Outdoor Microphone Class 2

OM226 permanent outdoor microphone is developed by BSWA Tech for outdoor noise monitor. Compared with semi-permanent outdoor microphone, the main improvement of permanent outdoor microphone is the built-in electrostatic actuator which can be used for remote system check. The external excitation signal source that can generate sine wave signal with frequency of 500 Hz and amplitude of 210 Vpeak ~ 280 Vpeak (about 150 Vrms ~ 200 Vrms) can excite the microphone to generate an output signal of 90 dB@1 KHz. Electrostatic actuator can be used for whole system check including microphone, cable and measuring instrument, but it cannot completely replace the sound calibration. Therefore, it is still necessary to use sound calibrator for calibration regularly.

OM226 outdoor microphones have been specially designed to achieve the free-field frequency response both in 0° and 90° direction of incidence within the limits of IEC 61672-1 Class 2. It’s suitable for aircraft, airport, urban, traffic and industrial noise measurement. Each microphone is supplied with an individual calibration certificate that contains the actual sensitivity and free-field frequency response data for the complete set of outdoor microphones. Users can use the calibration data to correct the measurement data for more accurate results.

OM226 meets the IP54 ingress protection rating. The windscreen, internal rain hood and dust mesh can fully protect microphone to against wind, rain, snow, dust and other severe weathers. The bird spike prevents impact of perching birds to the measurement.


     Meet the requirement of IEC 61672-1 Class 2 both in 0° and 90° direction of incidence without correction

     Delivered with individual calibration data

     IP54 enclosure to against rain, dust and perching birds

     The protection kit can be quickly remove for calibration

     Built-in electrostatic actuator for remote system check (external excitation signal source is required)

     ICCP power supply, low self-generated noise, typical noise level is ~23 dBA

     It can be installed on the tripod by 1/4-inch thread on the bottom


     Aircraft and airport noise measurement

     Urban, traffic and industrial noise measurement

     Acoustic measurement in severe weathers




Aircraft, airport, urban, traffic and industrial noise measurement


and 90°


GB/T 3785.1-2010 Class 2, IEC 61672-1:2013 Class 2, ANSI S1.4-1983 Type 2

Built-in Microphone

1/2” Prepolarized Microphone

Sound Field


Sensitivity@250 Hz (mV/Pa) (±3 dB)

40 (-28 dB re 1V/Pa)

Polarization Voltage

0 V (Prepolarized)

Frequency Response (Hz)

20 ~ 12.5 k (According to IEC 61672-1)

Dynamic Range (dBA ~ dB)

23 ~ 136

Self-generated Noise (dBA)


Maximum SPL (dB)

≥ 136 (3 % distortion)

Peak SPL (dBA)


Wind Noise Attenuation (dBA)

20 (wind speed 10 m/s)

Output Impedance

< 30 Ω

Maximum Output Voltage (Vpeak)


Power Supply

ICCP (2 mA ~ 20 mA, 4 mA Typ.)

Output Connector

BNC (Microphone), 10-32 UNF (Actuator)


Optional, IEEE 1451.4 compliant (default v0.9, optional v1.0)

Mounting Thread for Tripod

1/4” thread


IP54 (Microphone vertical placement only)

Operating Temperature Range (°C)

-30 ~ 80

Operating Humidity Range (%RH)

0 ~ 95

Dimensions (mm)

Ø90 x 222 (without extension rod), Ø90 x 376 (with extension rod)

Weight (g)

94 (without extension rod), 214 (with extension rod)

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