An Anechoic Chamber
 

The chamber can be used for experimental studies in electroacoustics, sonic equipment, noise characteristics of different articles, and psychoacoustics.


An Anechoic Chamber

The chamber is intended for the studies of electroacoustic characteristics of audiosystems, loud speakers, electric record players, magnetic tape recorders, sound channels of radio systems, and different kinds of acoustic sources; it allows also the measurements of noise characteristics of various equipment and articles, as well as psychophysical studies and studies of the effects related to binaural hearing.

Main technical characteristics

  • the inner dimensions with the sound absorbing lining installed 12x9x11 m3, the operating volume 1120 m3;
  • the sound-absorbing lining - 1 m long wedge-shaped absorbers made of staple glass fibre sized with resins;
  • in the chamber, a metal net is stretched over the chamber area at a height of 4 m measured from the lowest row of the wedge-shaped absorbers; the load capacity of the net is 300 kg per square meter;
  • the articles under test can be installed either on the net at any point within the chamber area, or on a specially mounted table with a rotary unit at the distances 1/4, 1/2, or 3/4 of the chamber length from its end wall along the chamber axis;
  • at a height of 2.5 m above the net, a microphone coordinate device is installed; the device can move along the entire chamber length and has 3 degrees of freedom;
  • beginning at net level and above, the chamber is lined with an "acoustically transparent" kapron sieve stretched over the wedge lining;
  • the chamber is certified within the frequency range 20 - 20000 Hz (certificate no. 209-93 of October 11, 1993);
  • the inherent noise of the chamber is 20 - 26 dB*A (during the day) and 13 - 14 dB*A (at night);
  • the total noise level recorded the measuring microphone is 58 dB;
  • the chamber is supplied with communication channels for the communication with the equipment room;
  • the chamber complies with the recommendations of the International Electrotechnical Commission.

Equipment room

The equipment room of area 42 m2 and volume 120 m3 is supplied with a controllable sound absorber simulating the conditions of a "living room", which allows the evaluation of the quality of sound produced by acoustic systems under the conditions close to the real operating ones.

The equipment room contains modern (Russian and foreign - B&K and other companies) equipment: transmitting-receiving and analyzing equipment, recording electroacoustic equipment, and equipment for sound intensity measurements.

The equipment allows the operation within the frequency ranges 20 - 25000 Hz (transmission channel) and 2 Hz - 200 kHz (reception channel) with a sufficiently high accuracy under the strictly controlled climatic conditions and the given chamber noise. All equipment is certified. The chamber is operated by qualified personnel.

The chamber is built on a separate foundation at a sufficiently quite district, which provides low levels of the inherent noise; judging from the characteristics of the chamber, it is one of the best anechoic chambers in Russia and in Europe. The chamber provides strictly controlled experimental conditions.