Question: what is the intensity of a fire alarm that has a sound level of 120 decibels
Answer: These are named with respect to their distinctive structure and include , March Time ( usually 120 pulses per minute but sometimes at 90 pulses or 20 pulses per minute , depending on the panel ) , Hi - Lo ( two different tones that alternate ) , Slow - Whoop ( slow rising sweep upwards in tone ) among others .