The 0.6% per foot obscuration specification for detector sensitivity relates to which aspect of detector performance?

The 0.6% per foot obscuration specification for detector sensitivity relates to which aspect of detector performance?

• A. The color of detectors
• B. The expected detection range in obscured air
• C. The mounting height
• D. The power supply to detectors

Answer: (B)

The situation tested is how obscuration of the air path affects a detector’s ability to sense smoke. The 0.6% per foot obscuration specification describes how much the detector’s optical signal is reduced for every foot of air that is obscured by smoke or dust. This directly determines the detector’s performance in smoky or dusty conditions, i.e., its expected detection range in obscured air. As obscuration increases along the path, the signal drops and the detector will detect smoke at a shorter distance, so the spec helps estimate how far away detection will occur under obscured conditions. The other options don’t relate to how sensitivity changes with obscuration.

The situation tested is how obscuration of the air path affects a detector’s ability to sense smoke. The 0.6% per foot obscuration specification describes how much the detector’s optical signal is reduced for every foot of air that is obscured by smoke or dust. This directly determines the detector’s performance in smoky or dusty conditions, i.e., its expected detection range in obscured air. As obscuration increases along the path, the signal drops and the detector will detect smoke at a shorter distance, so the spec helps estimate how far away detection will occur under obscured conditions. The other options don’t relate to how sensitivity changes with obscuration.