- "Percent obscuration per foot - Obscuration is any atmospheric phenomenon, except clouds, that restricts vertical visibility (e.g., dust, rain, snow, etc.). Percent obscuration per meter is the unit to measure the amount of Obscuration per foot. This unit is usually used in smoke detectors."
Conversion to SI and other common units
Communication Protocol Support
This engineering unit is supported by the following communication protocols:
- 2008 specification.