Sounder Level
Find the sound level a fire alarm system must reach.
Questions
Each answer describes what this tool calculates. The result is a design aid. Verify against the current standard.
How loud does a fire alarm sounder have to be?
NZS 4512:2010 Clause 406.3 sets a margin over the residual sound level. The margin is 10 dB with voice facilities for evacuation and 5 dB without them. The level also sits between 65 dB and 100 dB LAFmax. AmpSize reports whichever figure is higher.
What level is needed at a bedhead?
Clause 406.3 gives 75 dB LAFmax at the bedhead where a building provides accommodation. Clause 406.5 and Clause 406.7 cover other areas. Turn on the accommodation option to see the bedhead figure.
When are visual alerting devices required?
Clause 406.4 names three cases. AmpSize checks two of them: an ambient level above 90 dB LAeq(10min), and ear protectors worn as a routine. Read Clause 406.4 in full, because it carries a third case that this tool does not check.
How is the level measured?
Clause 406.3 gives the method and the meter standard. AmpSize reports the measurement height of 1.8 m. An occupiable balcony carries its own figure. Read Clause 406.3 in full before you record a level.
Does this tool show that a system complies?
No. AmpSize reports the levels of NZS 4512:2010 Clause 406 for the values you enter. It is a pointer, not a ruling. A fire alarm design is checked against the whole standard and against the declared functional requirements of the building.