Infra-Red Detectors & Linear Heat Detecting

Technical:

The detectors are designed to detect the changes in these emissions that occur when a hot body enters the field of view of the detector. By the use of both optical filtering and electronic analysis of the various parameters the system is blind to visible light from the sun or local luminaires, whilst being able to detect relatively low temperature material moving through the field of view. Infra-Red Detectors & Linear Heat Detecting The system is suited to situations where material or equipment that has a fire initiating potential is being moved. For example, the system can detect and prevent a FIRE from being imported into a protected area, as in the case of a burning road or rail vehicle entering a tunnel or building. In addition the system can monitor for materials in transit, which have not yet reached a flame condition, but have sufficient energy to initiate a fire upon arrival at their destination. A typical example is in the coal feed systems on power stations where coal on the ‘out field stack’ may very well smoulder with little adverse effect for long periods of time. However, if imported to the power station it may have devastating effects on conveyor systems, holding hoppers, blending plants, etc. The system comprises two primary elements - the sensor unit and an air supply. The latter is required such that a positive air pressure is maintained at the sensor unit optical lens aperture, thus preventing dust settling on the detector windows. This air purging is essential in dusty environments such as coal conveyors, and is recommended in even relatively clean applications. An air purge blower and unit are employed when an ‘on site’ clean air supply is not available. The sensor unit is located above or beside the materials transit path (conveyor, roadway, etc.) by means of the adjustable mounting bracket and aligned such that the monitored hazard passes through the sensor’s field of view. The distance and angle of the sensor determine the width of the monitored path. Typically conveyor widths of 1.6 to 4.2 m can be monitored with a sensor mounted 1.0 to 1.5 m above the conveyor at an angle of 0° to 55°. The air supply is monitored by a pressure switch which on air failure is signaled as a fault status. Alarm (Fire) conditions may be set for double knock operation. An internal multi-pole switch permits the various configuration selections.