The SuperDuct Signature Series smoke detector is the most advanced and most reliable device in its class. Designed for easy installation and superb reliability, SuperDuct represents the perfect balance of practical design and advanced technology. SuperDuct detectors feature a unique design that speeds installation and simplifies maintenance. Removable dust filters, conformally coated circuit boards, and optional water-resistant gaskets keep contaminants away from components, ensuring years of trouble-free service. When cleaning is required, the assemblies come apart easily and snap back together in seconds. A Signature Series photoelectric sensor is incorporated into the design of each GSA-SD duct smoke detector. This sensor inherits the power and benefits of this exceptional line of intelligent devices. Signature Series sensors gather analog information from their smoke sensing elements and convert it into digital signals. The sensor measures and analyses these signals and compares the information to historical readings and time patterns to make an alarm decision. Digital filters remove signal patterns that are not typical of fires, which virtually eliminates unwanted alarms.