Log In Sign Up

NOTE: This is an unformatted excerpt from our online fire protection training library.

Notification Appliances

Audible

Just How Loud?

The sound produced by the fire alarm system must be sufficient to be heard by the building occupants over the surrounding sounds and noise in the space. Audible notification appliances operating in the public mode must produce a minimum sound pressure level at least 15 dBA dBA
Sound pressure levels are measured in decibels (dB). There are various scales that are used, but the scale that most closely approximates human hearing is the "A" weighted scale. Thus, sound pressure levels measured on the "A" weighted scale are designated as "dBA". above the average ambient sound level or 5 dBA above the maximum sound level that lasts 60 seconds or more whichever is greater. The National Fire Alarm Code also limits the sound output from any notification appliance to a maximum of 110 dBA. Sound pressure levels are measured with a sound pressure level meter sound pressure level meter
The pictures on this page are examples of inexpensive sound pressure level meters. They have the ability to measure sound on various scales. The "A" weighted scale is used to measure the sound pressure output of fire alarm systems. Notice that the meter on the left is measuring a sound pressure level of 79 dBA..

Helpful Hint
NOTE: This is an unformatted excerpt from our online fire protection training library.

Contact Us:

Please fill in the fields below:

    Privacy Policy
    Please choose all that interest you.

    Contact Customer Service at AcademySupport@jensenhughes.com or 800-930-9414 option 1.

    Our regular support hours are 9:00 AM to 5:00 PM, Monday through Friday, except holidays...