Search results
Results from the WOW.Com Content Network
The PASS device sounds a loud (95 decibel) [1] audible alert to notify others in the area that the firefighter is in distress. On a fireground, the sound of an activated PASS device indicates a true emergency and results in an immediate response to rescue the firefighters in distress.
The standard fire alarm sound used in most of North America [citation needed]. Coding refers to the pattern or tones a notification appliance sounds in and is controlled either by the panel or by setting jumpers or DIP switches on the notification appliances. The majority of audible notification appliances installed prior to 1996 produced a ...
The white, round structure at the upper left is the piezoelectric horn that produces the alarm sound. An americium container from a smoke detector. An ionization smoke detector uses a radioisotope, typically americium-241, to ionize air; a difference due to smoke is detected and an alarm is generated. Ionization detectors are more sensitive to ...
A chirp is a signal in which the frequency increases (up-chirp) or decreases (down-chirp) with time. In some sources, the term chirp is used interchangeably with sweep signal . [ 1 ] It is commonly applied to sonar , radar , and laser systems, and to other applications, such as in spread-spectrum communications (see chirp spread spectrum ).
Some fire alarm systems utilize emergency voice alarm communication systems (EVAC) [17] to provide prerecorded and manual voice messages. Voice alarm systems are typically used in high-rise buildings, arenas, and other large "defend-in-place" occupancies such as hospitals and detention facilities where total evacuation is difficult to achieve.
Smoke detectors generally make a persistent beeping sound when their batteries run low, and a key part of fire prevention outreach involves encouraging people to replace batteries promptly instead of just removing them to make the beeping stop.
This is an accepted version of this page This is the latest accepted revision, reviewed on 14 January 2025. This is a list of onomatopoeias, i.e. words that imitate, resemble, or suggest the source of the sound that they describe. For more information, see the linked articles. Human vocal sounds Achoo, Atishoo, the sound of a sneeze Ahem, a sound made to clear the throat or to draw attention ...
The Mosquito or Mosquito alarm is a machine used to deter loitering by emitting sound at high frequency. In some versions, it is intentionally tuned to be heard primarily by younger people. Nicknamed "Mosquito" for the buzzing sound it plays, the device is marketed as a safety and security tool for preventing youths from congregating in ...