Ultra-sensitive laser-based technology protects electronic equipment.
Fire and smoke not only endanger lives, they can also cause varying degrees of damage to any type of facility. In a high-tech facility, such as a hospital, even a small fire can be devastating to its operation.
Electronic equipment is particularly vulnerable to smoke, much more so than heat. In many cases, the fire is contained to a small physical area and extinguished relatively quickly, but the entire facility is still negatively affected by the smoke.
For example, smoke in telecommunications facilities can disrupt service for up to several weeks, cause major disruptions in telephone communications and cause costly damage to equipment, even when the fire is promptly controlled. In critical applications, such as telecommunications switching stations, computer rooms, clean rooms, hospitals, museums, archives and historic buildings, installing the highest sensitivity spot-type smoke detectors is the best bet for protection against damage to electronic equipment.
Intelligent microprocessor-controlled smoke detectors that incorporate laser-based technology, such as System Sensor’s laser detector, are able to pinpoint the exact locations of a fire by identifying the address of the detector sensing the smoke. This can greatly reduce response time in real fire situations because smoke at such low levels is not visible to the human eye.
Ideal for critical applications, System Sensor’s laser detector is capable of sensing the presence of smoke and triggering an alarm up to 20 minutes earlier than standard photoelectric smoke detectors. While this type of ultrasensitive detector works on the same light-scattering principle as standard photoelectric detectors, System Sensor’s laser detector operates with sensitivity levels 100 times greater.
Using an extremely bright, controlled laser diode, the laser beam is transmitted through the chamber to a light trap to eliminate any reflection. If a particle of smoke enters the chamber, light from the laser is scattered.
System Sensor’s laser detector then uses its patented on-board algorithms to check the nature of the scattered light and determine if smoke is actually present. If smoke is positively confirmed, the alarm signals. The algorithms, which include multi-stage drift compensation, internal self-diagnostics and transient signal rejection algorithms, help prevent nuisance and false alarms, even when set to extremely high sensitivity.
Laser Detector vs. Aspirating Systems
Traditionally, the only way to achieve highly sensitive smoke detection was through the use of aspirating smoke-detection systems. Aspirating systems operate by drawing air and smoke through a network of pipe, or tubing, which is then routed throughout the protected space. By their nature, these types of systems are subject to the effects of dilution.
During an actual fire, smoke is drawn into the aspirating system’s pipe through one of its sampling ports. At the same time, the system’s other sampling ports may continue to draw clean air into the pipe from areas that the smoke has not yet reached. As a result, the sensitivity level in an aspirating system’s smoke sensor must be set much higher to offset the effects of dilution.
In critical applications that require very early warning detection, you can use either an aspirating system or a detector like System Sensor’s laser model. If the building already has a fire alarm control panel, or if one will be installed, System Sensor’s laser detector will be more cost effective for several reasons. For one, System Sensor’s laser detector will be installed on the same pair of wires as the other detectors that have been installed. Also, the company that installs the fire alarm control panel will install, service and maintain these detectors too.
Laser-based spot-type detectors, such as System Sensor’s Pinnacle™ or Notifier’s View, are not subject to dilution. In fact, they perform as good or better than aspirating technologies in high-sensitivity environments. In an aspirating system, the smoke is sensed at one central unit, allowing dilution to negatively affect response time. With Pinnacle, measurement points away from the fire do not degrade response time, regardless of the size of the fire.
Flexibility and Cost Savings
In general, systems that incorporate Pinnacle can be extremely flexible and cost effective. For instance, one fire alarm control panel loop can have a variety of smoke detectors installed on one pair of wires. Only critical areas with high-tech electronic equipment that require ultra-high sensitive smoke detection need to use Pinnacle.
Non-critical areas can simply use standard photoelectric or ionization smoke detectors. Regardless of type, all of the detectors install in the same mounting bases, so system designers can seamlessly mix Pinnacle with other standard detection technologies, thereby reducing overall cost.
Tags: Smoke detection
Posted in Intelligent Detection, Winter 2005
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