PressInformation XARION Laser Acoustics GmbH

Vienna, 18.05.2017

SENSOR+TEST, Hall5 / Booth5-344/1

World’s first airborne ultrasound microphone with a bandwidth of 1 MHz

Laser-based microphone opens up new applications in the industry

XARION Laser Acoustics GmbH presents a unique, laser-based ultrasound microphone, „Eta250Ultra“. TheEta250Ultracovers the entire frequency range from 10 Hz to 1 MHz with a single sensor. This is possible due to a membrane-free optical sensor technique, which is protected by several worldwide patents.

Abb. 1: Ultrasound microphone Eta250 Ultra for sound waves from 10 Hz – 1 MHz.

„The crucial advantage of measuring airborne sound at ultrasound frequencies as high as 1 MHz lies in its limited propagation length of roughly 1 metre“, explains founder Balthasar Fischer. He highlights that “therefore, the Eta250Ultra isthe only acoustic measuring instrument worldwideproviding a statistically robust process monitoring tool that is not compromised by ambient noises”.

XARION’s sensor makes use of the fact that sound waves are nothing other than variations in air pressure, which in turn cause the wavelength of light to change correspondingly while passing through it. A rigid interferometer is used to measure these tiny variations in the stabilised frequency of the laser. That way, moving parts, which generallyproduce disturbing mechanical resonances and limit the bandwidth in conventional microphones,become completely obsolete in case of the all-optical microphone.

Fig. 2: Principle of the laser-optical sound measurement: Oscillations of sound waves correspond to alternating layers of denser and thinner air. The density of a medium determines the speed at which light travels. The ultrasound microphone Eta250 Ultra exploits this effect by measuring these variations of the speed of light, which are induced by sound waves passing through the laser beam in between two mirrors.

The Eta250Ultra’s optical sensor (size: 2mm measuring distance) connects to the controller unit via a fibre optic cable. The controller unit contains the laser, the detection unit, as well as a preamplifier. Since the signal is carried in an optical fibre cable, it is possible to use very long cables without significant signal losses or interference issues.

Fig. 2: Sensor head: Its small size (1 mm x 4 mm) and its outstanding electromagnetic compatibility make it possible to measure sound even in complex and harsh environments.

Besides the Eta250Ultra (100 dB dynamic range, 50 µPa self-noise), XARION offers the Eta100Ultra, which is designed for very high sound pressure levels and supports signals up to 20 kPa (180 dB rel. 20μPa). It provides the same frequency range (10 Hz to 1 MHz) as the Eta250Ultra.

XARION presents theEta250Ultrafrom30/05/16 until01/06/17 in Nürnbergat the trade fairSENSOR+TEST, Hall 5 / Booth 5-344/1.

AboutXARION

XARION Laser Acoustics GmbH, based in Vienna, Austria, is the world leader in the production of industrial microphones that measure air density variations of sound waves directly by optical means.The multi-patented measuring principle is inherently linear, resonance-free and supports an extraordinarily wide frequency range from 10 Hz to 1 MHz in air and up to 20 MHz in liquids. XARION’s plug-and-play solutions open up unseen possibilities in the areas of sound field characterisation, tomography/medical technology, process control, as well as non-destructive material testing.The optical microphone is operational even under the harshest environmental conditions, as in the presence of high electromagnetic fields or intense surrounding noise. In 2013, the AMA FachverbandfürSensorik granted Balthasar Fischer the award „AMA Innovationspreis“. In 2016, the company won the code_n award and the Berthold-Leibinger-Innovationspreis. Among XARION’s investors is TRUMPF, machine tools producerand world market leader for industrial lasers.

Press Contact:

XARION Laser Acoustics GmbH

Oliver Freitag

Ghegastraße 3

A-1030 Vienna / Austria

Tel.: +43 1 9076076-951