Details are given of an instrument for checking if outdoor noise conforms with recent US legislation. By adapting preexisting equipment including sound level meters, microphones, level recorders and statistical analysers, together with a suitable tape recorder control, a complete system was built. In order to achieve the required 2 db accuracy, portable battery-operated recorders with fairly flat frequency response down to at least 80 hz were used. Tests undertaken to find the most suitable recorders are described. The main problem with the system is the time taken for replaying the tape into the level recorder/statistical analyser. Advantages of the system are discussed. Details are also given of a dedicated instrument, the 4426 statistical analyser and level processor, its operation and efficiency. Mention is made of the need for permanent noise monitoring in the vicinity of airports or large and noisy industrial plants and of the special measures required for protecting windscreens and microphone cartridges. The need is stressed for the annual calibration of all apparatus used to make official measurements. /TRRL/

  • Corporate Authors:

    Trade and Technical Press, Limited

    Crown House
    Morden, Surrey SM4 5EW,   England 
  • Authors:
    • Kuehn, J
  • Publication Date: 1976-1

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00138891
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: ITRD, TRIS
  • Created Date: Oct 26 1976 12:00AM