| 요약2 |
In this study, effects of voltage dropping due to distance increasement between receiver and terminal circuit were examined and especially effects on fire alarm sound pressure level in receiving point were identified according to plan types. Following are results. (1) With the voltage dropping increases, the fire alarm sound pressure level decreases. When voltage dropped by -20%, alarm bell sound decreases by -3.5dB and siren does by -2.3dB. (2) In the experiments of sound pressure level variation caused by voltage dropping and plan types, the sound pressure level reduction in corridor type plan is bigger than that of stairway type plan's. The attenuated sound pressure level due to voltage dropping could not be heard in lecture room and so, this problem should be considered. |