Brüel & Kjær launches new microphone technology
Brüel & Kjær Sound & Vibration has launched a microphone using ground-breaking technology. The surface microphone is the first of its kind and is based on Brüel & Kjær's new, patent-pending, microphone manufacturing technology which enables the same high stability and uniformity to be achieved with the flat, compact design as in the traditional Brüel & Kjær microphones and preamplifiers.
The surface microphone was developed following a request from Airbus for a new aerodynamic microphone for use during in-flight testing where traditional flush-mounted microphones were not possible as this would require drilling holes in the aircraft body. A key challenge was the level of miniaturisation required, which meant developing a new way of integrating electronics and mechanics. The result is a flat microphone measuring just 2.5mm in height, with built-in preamplifier, all made from titanium to ensure a high resistance to corrosion. Flight tests have been performed at Airbus, proving that the microphone is robust and corrosion-resistant, despite its small size. It can withstand de-icing detergent and harsh environments, such as for example, normal aeroplane cruising altitudes of 30,000 feet, turbulence, rain, hailstorms and a temperature range from -50°C to +100°C.
Although ideal for use on aircraft, the surface microphone has been specifically designed for applications which require the measuring of sound pressure (noise) in limited spaces and where flush mounting of conventional microphone/preamplifier combinations would be impossible or cause undesired side effects. This is particularly the case in the automotive industry where aerodynamic noise, as well as noise such as that created by side mirrors, has always been of great concern to automotive engineers. Surface microphones can measure directly on the surface of a window, eliminating the need to drill holes. Other applications include measurement of brake squeal and measurement in confined spaces close to the engine.