AC-PSDS. The Yale AC-PSDS is an interlinked smoke detector for the Yale Sync alarm range and has a loud 85dB siren. It has a reflective photoelectric sensor to detect smoke from any source, especially smouldering fires and the optional ability to detect the rate of rising heat when temperatures exceed 57.25°C or rise by 8.25°C per minute. There is an alarm silence button and the unit has a built in emergency light which can be activated by the user. . Interlinked smoke detector. Loud 85dB siren. Reflective photoelectric sensor. Wireless