PCB Piezotronics is launching a new prepolarised array microphone for harsh environments and applications such as automotive brake and tyre noise testing. The model 130A24 is a ½in (12mm) free-field polarised array microphone and preamplifier system with replaceable water and dust-resistant cover.
The 130A24's acoustically transparent cover provides an unobtrusive alternative to windscreens and a more consistent response compared with rubber protective covers that are normally used in the harsh environments for which this microphone is well suited. The 130A24 features a wide dynamic range from 30dBA (inherent cartridge thermal noise level) to 143dB (150dB maximum before clipping) and is equipped with a rugged stainless steel grid cap similar to PCB's high-end condenser microphones.
Specifications include frequency range from 20Hz to 16kHz (+/-3dB), sensitivity of 10mV/Pa and operating temperature range from -10 to +50degC. Model 130A24 is an ICP sensor requiring 2-20mA constant current supply and uses standard coaxial cables enabling existing ICP power supplies and cables to be used. This interchangeability can result in significant per-channel cost savings as well as reducing test set up times.
Acoustic pressure waves can be altered by objects in the sound field including the microphone used to measure it. To correct for this, free-field microphones such as model 130A24 are designed to compensate for their own presence and provide more accurate measurements. Although the 130A24 is optimised for flat response in a free-field, it also provides excellent response in many pressure and diffuse-field microphone applications. As well as automotive brake and tyre noise testing, the 130A24 is also suitable for acoustic holography, beamforming, noise source identification, general audible range testing, non-contact defect detection and acoustic tests where oil splash, high humidity or dust is a concern.
The new model 130A24 water and dust-resistant ½in array microphone and preamplifier is available from stock for immediate delivery. Go to www.pcbpiezotronics.co.uk for further details.