ULTRA-SMALL MICROPHONE SCALES NEW HEIGHTS OF
SURFACE DYNAMIC PRESSURE MEASUREMENT PERFORMANCE
A new, 2.5mm low profile, aerodynamically shaped microphone
has been introduced by Bruel & 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 4949s 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
¼-inch flush-mounted microphone. The microphone supports
TEDS (Transducer Electronic Data Sheet) and, combined with
proven system solutions such as PULSE multi-analysers, brings
new dimensions and ease of use to the test engineer, commented
Bruel&Kjaer technical sales engineer, Jeremy Bryceson.
For more information, please contact :-
Bruel & Kjaer UK Ltd.
Bedford House, Rutherford, Close, Stevenage, Herts. SG1 2ND. UK
Tel: +44(0) 1438 739000, Fax: +44(0) 1438 739099