Obscuration definition | What is Obscuration
This page mentions Obscuration definition. The term Obscuration is used as unit of measurement for sensitivity of smoke detector.
Obscuration definition :
It is the measurement unit for sensitivity of the smoke detectors. Higher the value of obscuration, higher the smoke concentration levels and lower the visibility. Lower the value, lower is the smoke concentration and higher the visibility. It is measured in obs/m or obs/ft.
There are different types of smoke detectors. They have different obscuration specification. Based on this and other factors appropriate smoke detector need to be choosen for particular application based on area to be protected from accidental fire.
Following table mentions obscuration ratings of major smoke detectors in use today.
|Smoke detector type||Obscuration rating|
|Photoelectric smoke detector||2% obs/ft to 4% obs/ft|
|Ionisation Smoke detector||0.8% obs/ft to 1.5% obs/ft|
|Laser based Smoke detector||0.02% obs/ft to 2% obs/ft|
|Aspiration Smoke detector||0.0015% obs/ft to 6.25% obs/ft|