Video Detection and Monitoring of Smoke Conditions
Initial tests have been performed to assess detection limits and smoke obscuration monitoring for a video scene under different lighting and smoke concentration conditions. An illuminated exit sign located in the fire emulator/detector evaluator duct was used as the scene. A fixed gain, black and white CCD camera, coupled to a manual-focus, manual-iris video zoom lens was used. The lens itself was attached to a rigid boroscope, which penetrated the duct and viewed the exit sign from a distance of 2 m. Flaming soot, smoldering wood smoke, and ISO test dust were used to obscure the scene. Repeated tests were performed with the external scene lighting turned on or off. Scenes ranged from smoke/dust free conditions to a completely obscured exit sign. Analysis of the data shows that a CCD camera pointed at a continuously illuminated source, like an exit sign, can provide an indication of obscuring aerosols in the scene (i.e. detection). Furthermore, an assessment of the visibility conditions can be obtained from the scene under fixed lighting conditions. Analysis of the loss of contrast between the illuminated letters and the background of the sign provides a more general assessment of visibility conditions.
To Be Determined
fire emulator/detector evaluator, smoke alarms, test methods, video detection, visibility