The new high resolution infrasound sensor

Detection of Very low frequency acoustic signals in a wide frequency range with excellent resolution and high dynamic, with remote calibration capability.

The MB3 A provide an output pressure or pressure derivative.

The core of the sensor is an aneroid capsule coupled with a magnet & coil transducer (similar to the one used on short period seismic sensor ZM500). A secondary coil wrapped around the main one ensures remote calibration capability.

Product sold under licence of CEA

Physical characteristics

Compact and lighter than the MB 2005, MB3A is a concentrate of technology and performance: As its predecessor, it consists in an analog version that has to be plugged to a digitizer. It is compliant with most of model sold in the market

D 110 mm / H 139 mm / Weight 3.0 kg
Bandwidth Pressure output: 0,01 - 28 Hz / Pressure derivative output: DC – 28 Hz
Self-Noise < 10 dB under the LNM (Low Noise Model)
Resolution 1,75 mPa RMS on [0,02 ; 4] Hz
Sensitivity Pressure output: 20mV/Pa / Pressure Derivative Output: 2mV/pa.s-1 / Calibration output: 6 V/Pa
Self noise

The MB3 is remarkable for an extremely low level of instrumental noise (<-80 dB.Pa / v Hz @ 1 Hz) allowing the sensor to resolve more than 10 dB the Low Noise Model. This sensor has been designed especially to meet the requirements of infrasound stations of the IMS network (International Monitoring System) installed as part of the CTBT (Comprehensive nuclear Test Ban Treaty)

Transfer function and sensitivity

The transfer function is an important parameter to ensure the results from the treatment of the acquired signals. The sensor is adjusted at factory to a value of sensitivity of 20 mV / Pa at 1 Hz

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