소방차량 및 소방장비로부터 발생하는 소음의 크기 및 주파수 특성에 관한 연구

Abstract

Noise at each 1/3 octave band frequency was measured for noise sources operated in the fire cars and equipments and facilities used by firefighters from 21 January to 15 February and from 29 April to 6 May 2013 using the Sound Level Meter built in 1/3 Octave Band Frequency Analyzer (Model: 2260 Observer). Sound pressure levels (SPLs) of both electric motor sirens and electric air sirens ranged from 85 to 90 dB. SPLs were measured at 80~88 dB during the PTO(Power Take-off) units operation and 90 dB during the electric generator operation. Noise reduction levels showed a little bit wide range from 0 to 17 dB by closing the widows of the fire cars. Apparent peaks were appeared at 800 Hz and 1600 Hz in the frequency analysis of the electric motor siren sound. The electric air siren sound showed high SPL for wide range of frequencies between 630 Hz and 1600 Hz. Electric generator also showed a wide frequency range from 500 to 2000 Hz. A number of high noise equipments such as cutter, chain saw, jack hammer and drill are used by fire fighters. In general, these equipments generate high noise greater than 100 dB while using in the field. Sound levels from the engine of these equipments range from 90 dB to 105 while idling and accelerating. Two types of rescue whistles are used. One is for fire fighters and the other for SCBA. Both whistles’ SPLs were 90~100 dB but exposure chances are rare and durations are generally short. Frequency range of the most equipments was 500~2500 Hz. While working with these equipments, the frequency range shifted up to higher region.