PLC has been providing sensors to the industry for over 20 years. Our sensors are UL 916 certified and RoHS compliant. Quite simply, they measure light levels, telling the controller how much additional light is required to maintain proper light levels. They are always reliable and always accurate. Each sensor is specifically designed for use in outdoor, indoor, skylight and atrium applications. They integrate easily into all PLC lighting control systems as well as those of other manufacturers.