What is the frequency of the fire alarm? Answer
Those who have multiple tone increases should arrive at 70dB within 10 seconds of the start of the alarm tone.
With an alarm tone (including a tone speaker). The same below) send the fire alarm alarm sound pressure of live, in accordance with the following provisions, when voltage is applied, in an anechoic chamber at the 1m center in front of the alarm distance, the sound pressure should be above 70 dB, and the state should be able to last longer than 1 minutes.
Fire alarms shall be in accordance with the following rules when interrupted:(1) the duration of inactivity (except for the silent time of the singing time) is less than 2 seconds, and the singing time is above the resting time.(2) in the singing time, the part of the alarm sound pressure below 70 dB is called the "silent time", and the alarm sound time should be above the sound time.(3) the time of no sound in the time of motion shall be less than 2 seconds.
