How Smoke Detectors Work
Smoke detectors have become so widely used that these ubiquitous devices seem to be part of every building's interior. But how do these life-saving devices work?
In this tutorial, IPVM examines the working principle of smoke detectors, what types of fire they are most suitable for, etc.
This report is part of our explainer series, including (amongst others):
- How Environmental Sensors Work
- How Tasers / Conducted Energy Weapons Work
- How Surveillance Balloons Work
- How Millimeter Wave Airport Body Scanners Work
Smoke *********: ********** *** *************
********** *** ************* ***** ********* *** the *** **** ***** ** ***** detectors. ***** ********* *** ***** ** different ************ *** *** ********* ** ****** ********* ***** ** fire *****: ********** ***** ********* *** **** effective ******* ******* *****, ******* ************* are ***** *** ********** *****, ********.
*** ***** ***** ***** ** ******** of *** ***** ** ***** *********:
Ionization ***** ********
********** ***** ********* *** * *********** element **** ******* *** ******** ** air *********, ***** *** **** ** a ******** ** *** ******** ******* within *** ********, ** **** ******* to ** *****.
*** ********** ******** ******** ** *** plates ********* ** * ******* *** a ***** ******* ** * *********** element, *********-***, *** *******, ** ***** below:
*** *** ********* ******** *** ******** interact **** *** *************** ********* **** the *******. ** *** ******* ****** ionization, ************ ******* *** ********* *** separated **** *** ***-******* (*** ******** and *** ********) *********, ****** ****. After ****, ******** **** ******* ** the ********** ******* ***** *** ******** to ********, **** ******** ** ********** current.
**** ****** ** ***** ********* ******** the ********. **** ******* *** ******** of *** *** ********* (*.*., ** takes ****** *** **** ** ***** the ******) ***, ** ****, ***** to ******* ************ ***, *********, ********** current ** *** ********. ** *** current ***** ***** * ******* *********, the ***** ** *********.
*** ******** ********, **** ********** ************* * ****** ********** *******(* ********* *******) **** ** *********** closed ** ***** ********* *** ** still ******** ** ************* *******. ***** detectors *** ****** **** ******* *********.
Radioactive ******* ** ***** *********: ****** ********
*********** **** ********** ***** ********* *** radioactive *********, ***** ***** ** ****** questions. **** ***** ************ *********-***** ***** ********* ******, *** *** National ******* ********** **********, *** ***** on *** **** ******, ***** ********* do *** **** *** ****** **** for * ******:
**-*** ********* **** ***** *********. ***** particles **** ****** * *** ******, are ****** ******* *** **** ******* a ****** ****** ** ***** **** the ****.
**-*** **** **** ***** ********* ** an ****** ** *** ** ****** be ************* **** ******* ********* **** space *** *** *****.
*******, *** **** ** *** ******* is ********** ***** - *****.** **********(************* */****** ** * ***** ** salt).
Photoelectrical ***** *********
*************** ***** ********* *** ***** ** either ********** ** *********** ** ***** caused ** ***** ********* ********* ** the ***, *** ****** ********** *********, they ** *** *** *** *********** materials. ******* ******** ********** ** *************** detectors, **** *** *** ******* *****, including * ***** ****** *** * light-sensing *******.
*** **** ****** ***** ********* ** that *** ***** ********* **** ****** (1) ******* *** *****-******* ******* *** will **** *** ** **** ***** from *** ****** ** (*) ******* the ***** **** *** ******* ******* (if ** ***** ** *******, ** light ******* *** ****** ** **** type ** ************* ******), ** ***** below:
** *** ***** ****, *** ****** of ***** ******** ** *** *****-******* element ** ********* **** ** ********** current. *********, **** *** ****** ** registered ***** *********, *** ******* ***** and ******** *** ***** **** ** reaches * ******* *****.
** *** ****** ****, *** ******* will ******** **** *** ***** *************, and *** ***** **** ***** **** a ********* ** *******.
Dual ****** ********
* ****-****** ***** ******** ** * combination ** ************* *** ********** ***** detectors *** ** *** *** ********* to ** ******* ********* *** **** types ** ***** (********** *** *******). However, ** ** *** ** **** expensive **** ************* *** ********** *********.
*******
*********, *** *** *** * ***** detector *** ***** $**, *** ***** are **** ********, **** ******** **** ***** *****, ***** ***** $***. *******, ** includes * ****** ******** ******** *** other ***************.
Photoelectrical ***** ********* **. *********** ****** *******
*** ********* ** *** ****** **** of ************* ***** ******** (**** ***** scatters *** *****) ** ******* ** the ********* ** *** *********** ****** sensors; *******, ***** *** ******* ***********.
*** ** *** **** *********** ** the ******** **********. ** ******* ******* a ****** **** **** ****-********* ******* elements, ** *** ***** ** ******** the ****** ** *** ********** ***** and *** **** ** *********. ***** detectors, ** *** ***** ****, ** not **** **** ************.
************, ***** ********* *** **** ******* sensors ******* * **** ******* ******** is ******** ** ******** ** ***** (simple ************ **** *******), ******* ** sensors **** ******** ************ *** **** and ************* **********.
*** * ******** *********** ** *** PM ******* **** *** ***** **** for **** *********, ******* ********* ********.
How ** **** ***** ********* *****
*** ******** ** ***** ********* **** include ***** **** ** "*************," "**********" (or "********"), ** "**** ******" ** the ******* *********** ** ***** *** understands **** **** ** ******** ** is.
************, ********* ********* **** ********** ** the ***** ********, ** ***** *****:
False ******
***** ********* *** *********** ***** ** false ****** *** ** * ****** of ********* *******. *** **** ****** sources ** ***** ****** *** *****, dust, ******* *****, *** ******** ******* compounds (****) ** ****** ** ******** supplies, ***.
******* ****** ***** ***** ****** ** a *** ******* ** *** ******** (however, *** *** ********* ***** **** running *** ** *******, ** ** is ********* ** ***** *** ******* regularly).
** ****** ***** ******, **** ***** detectors *** ******** *** *** ******* to ********* ***** ****** ****** ** humidity *** ********.
** * **** *****, **** (******** Fire ********** ***********) ********* **** ********** smoke ************** **% ** ***** ******. **** *** *** **** ** find **** ****** **** ********** *** same *****. *******, ******* *** **** **** *********:
******* ***** ****** [*************] *** **** immune ** ******* ******** *********** **** ionization-type ***** ****** ******* ** *** insensitivity ** **** ***** ******** [**** as ******* ***** *** *******]
Fire ******** *************' ***************
***** ***** *********** ***** *********, *** ** **** Administration (****) *** *** **** * superior **** ** ******** ******* "***** fire ** *********" *** ******* ****** both ********** *** ************* ***** ********* or * **** ****** ******** ********* in ***'* ****, **************** *********** ** **** ************** *** *** *** ** ************* smoke *********, **** ****:
*** ******** ** *** *** **photoelectric **********, or alarms that pass the new 8th Edition UL217 Standard, have the potential to save hundreds of lives each year and should ** ******** ** *** ********** ** ****** ** ******* ** *** **** ** ***** ****. [emphasis added]
Other ************
* ***** ******** ***** ****** ** another ******* ********** *** ***** ********* that ** **** ** ******'***** ***** *** ** ********.
*** **** ********* *** ***** ******** sensor ** *******:
*** *****-******** ****** ******** * *********** infrared ************* ******** ********** ****** **** an ********** **** ***. ** ****** a ****** ****** ** ***** ** a ********* ******* ** *** ***** spectrum, ****’* *****-******** ****** ***** ** an ********** ******* ** *** ***** and ***** ***** *********, ***** *** vary ** *** ****** ** *** fire ***** ********.
*** ******** ** * ****** ***** source (* **** ***), *** **** and ****,*** ******* ************* *********.