Ultra-small microphone hits new performance level

Edited by the Processingtalk editorial team Nov 12, 2004

A new, 2.5mm low profile, aerodynamically shaped microphone has been introduced by Bruel and Kjaer to simplify the accurate measurement of true surface dynamic pressure (sound pressure)

A new, 2.5mm low profile, aerodynamically shaped microphone has been introduced by Bruel and Kjaer to simplify the measurement of true surface dynamic pressure (sound pressure) in a number of engineering applications.

Even though the innovative Surface Microphone Type 4949 is only 20mm in diameter with a height of 2.5mm including its integrated preamplifier, the acoustical performance (5Hz to 20kHz) and dynamic range (30 to 140dB) of the new pre-polarised device are equivalent to those of traditional, much bulkier flush-mounted microphones.

The new all-titanium microphone can be easily integrated into a flexible mounting pad that eliminates the need to drill holes in the test object and minimises the costs of mounting the microphone.

Robust and corrosion-resistant, the simple-to-use, accurate surface microphone can withstand harsh environments including wet and oily conditions.

The Type 4949 ultra-low 2.5mm profile and novel, flexible, disc-formed mounting pad make it ideal for measurement of dynamic pressure (sound pressure) directly on the surface of a aircraft, vehicle or wind power blade or for sound pressure measurements in limited spaces and where flush mounting of conventional microphone/preamplifier combinations would be impossible or may cause undesired side effects.

The microphone is also suitable for a wide range of test and measurement applications including: acoustical fatigue testing; aerodynamic noise measurements; noise reduction measurements; transfer path analysis as well as lift and down-force analysis.

"Despite its total height of only 2.5mm, the new Surface Microphone Type 4949 has an integrated pre-amplifier and an acoustical performance and dynamic range equivalent to that of a traditional 1/4-inch flush-mounted microphone.

The microphone supports TEDS (Transducer Electronic Data Sheet) and, combined with proven system solutions such as PULSE T multi-analysers, brings new dimensions and ease of use to the test engineer," commented Bruel and Kjaer technical sales engineer, Jeremy Bryceson.