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Bruel & Kjaer 4191 1/2 Microphone - NEW

Bruel & Kjaer 4191 1/2 Microphone - NEW

Bruel & Kjaer 4191 1/2 Microphone - NEW Цена:   525.00 лв

Поръчка на Bruel & Kjaer 4191 1/2 Microphone - NEW

4191  1/2-inch Free-field Microphone, 3 Hz to 40 kHz, 200V Polarization

Price: 269 euro

Type 4191 is designed for high-precision, free-field measurements where a wide bandwidth is required. Being externally polarized, Type 4191 must be used with a classical preamplifier.


  • Precision measurements to 40 kHz
  • Premium class sound level meters
  • Equipment complying with IEC 61672 class 1


  • Sensitivity: 12.5 mV/Pa
  • Frequency: 3.15 Hz – 40 kHz
  • Dynamic Range: 20 – 162 dB
  • Temperature: – 30 to + 300°C (– 22to + 572°F)
  • Polarization: 200 V

Use of Free-field Microphones

At higher frequencies reflections and diffractions causes a pressure increase in front of the diaphragm of a microphone. If not corrected for, this would result in an increased output voltage. A free-field optimisation means that the frequency response of the microphone has been designed in such a way that the free-field response at 0 degrees incidence is flat. This microphone is optimised for use with the protection grid in place.

Free-field microphones are commonly used for sound measurement in an anechoic chamber or far away from reflecting buildings, etc. Another area for free-field microphones is for general electroacoustic measurements like loudspeaker and microphone measurements.

With an upper frequency of 40 kHz, Type 4191 is especially suited all high-precision electroacoustic measurements as well as general acoustic measurements where a robust and stable free-field microphone is required. Despite the 40 kHz upper frequency, this microphone is optimised to operate with the protection grid in place.

Manufacturing and Stability

A press-fitted, stainless-steel diaphragm ensures superior long-term stability and mechanical robustness – Type 4191 will withstand the 1 m drop test of IEC 60068 – 2 – 32.

All Brüel & Kjær Measuring Microphones are assembled in a clean room. This ensures that the microphones maintain their inherent low noise floor and high stability, even when used in environments with a combination of high humidity and high temperature.

Polarization Voltage

Type 4191 requires an external polarization voltage and must therefore be used with a classical preamplifier. Externally polarized microphones may be used at higher temperatures without severe changes in sensitivity.

Type 4191 is available in TEDS combinations with the classical Microphone Preamplifier Type 2669. The TEDS microphone is considered one unit and has been sealed in a clean...


Capacitance 18 pF
Diameter 1/2 inch
Dyn. Range 21.4 - 161 dB
Freq. Range 3.15 - 40000 Hz
Inherent Noise 20 dB A
Lower Limiting Frequency -3dB  Hz
Optimised Free field 
Polarization Ext. polarized 
Polarisation Voltage 200 V
Preamplifier Included Yes 
Pressure Coefficient – 0.007 dB/kPa
Sensitivity 12.5 mV/Pa
Standards IEC 61094-4 WS2F
IEC 61672 Class 1ANSI 1.4 Type 2 
Temperature Coefficient - 0.002 dB/ºC
Temperature Range -30 - 300 ºC (-22.0 - 572.0 °F)
Venting Side

Bruel & Kjaer