Posted to News on 15th Apr 2007, 10:33
2007 catalogue includes standards, glossary and much more
Bruel & Kjaer (B&K) is publishing its 2007 Microphones and Conditioning Product Catalogue, which features new, state-of-the-art models in its range of measuring microphones and related equipment for the measurement of sound.
In response to customer requests, the 2007 catalogue includes connection charts for the extended ranges of microphones (diffuse-field, pressure-field, low-noise), amplifiers, cables and power-supplies. It also includes information about acoustical, regulatory and related standards, plus a glossary of acoustical terms.
New to this version are articles about different branches of acoustical measurement and selecting the right microphone for individual applications. It outlines the operating principles of current microphone technologies, signal conditioning equipment, power supplies and calibration equipment.
As both a long-time pioneer and continuing innovator of sound measurement, Bruel & Kjaer includes modern equivalents to old or discontinued models as well as new models - such as the Type 4955 low-noise microphone - in the new catalogue.
The catalogue also provides information about the services Bruel & Kjaer provides to maintain end-users' equipment and to ensure acoustical measurement integrity through the entire lifetime of the products.
Type 2699 A-weighted Deltatron pre-amplifier has two engraved rings
The Type 2699 combines a Deltatron preamplifier and an A-weighting filter in one unit. This is useful for in-car measurements in the presence of large low-frequency components. The fact that A-weighting is applied is contained in the Type 2699's Transducer Electronic Datasheet (TEDS) and the two rings engraved on its shell visibly differentiate the Type 2699 from other pre-amplifiers without A-weighting to eliminate testing errors.
New free-field microphones
Free-field microphones are particularly suitable for making measurements away from reflecting surfaces - for example, when making outdoor measurements with a sound level meter, or in an anechoic chamber or other acoustically well-damped indoor environments.
Three new free-field microphones are being introduced
The Type 4955 1/2inch low-noise microphone and pre-amplifier is a 1/2inch all-titanium TEDS microphone with a guaranteed noise-floor less than 6.5 dB(A). It is optimised for sound power measurements to ISO 3745 and for characterising the noise floor of anechoic chambers.
Type 4950 1/2inch pre-polarised free-field for 2250 light conforms to standards IEC 61672 Class 1 and ANSI S1.4 Type 1. Its optimised frequency response (+/-2dB) is 4-16kHz and its dynamic range (with pre-amplifier type 2669) is 14-142dB(A).
Types 4954 and 4954A 1/4inch pre-polarised free-field microphones conform to standards IEC 61094 - 4 WS3F. Its optimised frequency response (+/-2dB) is 4-80kHz and its dynamic range (with pre-amplifier type 2670) is 40-164dB(A). The Type 4954A has an integral Deltatron preamplifier and is identical to the type 4954 in all other respects.
New array microphone and cable
Array applications are gaining popularity for noise source identification. Types 4957 and 4958 are high-sensitivity array microphones and feature an integral DeltaTron pre-amplifier. Each microphone's amplitude and phase corrections are individually measured and stored in the Transducer Electronic Datasheet (TEDS). When used with a measurement system that supports amplitude and phase correction, noise source identification can be made with greater precision.
4957 1/4inch Array microphone 17mV/Pa 50 to 10kHz: The 4957 1/4inch array microphone: nominal sensitivity 17mV/Pa, optimised frequency response (+/-2dB) 50-10kHz.
Type 4958 1/4inch array microphone 17mV/Pa 20 to 20kHz: The specification of the 4958 is identical that of the 4957, but it has a different optimised frequency response (+/-2dB) 20-20kHz.
