measurement microphone / condenser / externally-polarized / pressure
Bruel and Kjaer
pressure, 1", low-noise, polarized
Designed for measuring ultra-low sound pressure levels.
Brüel & Kjær has developed the 1” Condenser Microphone Type 4179 and Microphone Preamplifier Type 2660 system for measuring ultra-low sound pressure levels.
Monitoring of very low background noise levels
Sound Power measurement of very-low-level sources
Distanced measurement of very-low-level compressor, fan or motor noise where close measurements are impaired by wind-induced noise
High-quality, conventional 1” condenser microphones, such as B&K Types 4144 and 4145, and half-inch diameter Types 4189 and 4190, provide for the majority of noise measurements to IEC, ISO and ANSI standards. However, for measurements around the 20 μPA reference pressure, a very low noise floor in the 1/3-octave bands between 20 Hz and 20 kHz is needed.
LOW NOISE FLOOR
The microphone and preamplifier system, with a noise floor of typically -2,5dB(A), provides for this area without compomising the useful frequency range and omnidirectivity of a microphone intended for precision measurements.
With narrow-band analysis, the noise floor falls to approximately -16dB for 1/3-octave bandwidth at 1 kHz, and -34dB for 3,16Hz bandwidth at 1 kHz. The system is thus well-suited to both laboratory and industrial applications ranging from hearing research to the measurement of very-low-level machine noise.