The LMLS-400 is a closed loop photosensor that measures the ambient light level in order to automatically switch or dim one zone of lighting. It is part of a Digital Lighting Management (DLM) system and sends light level signals to control loads connected to DLM on/off or dimming room controllers. The LMLS-400 has a photodiode with an extended range of 1-10,000 footcandles (fc), and photopic correction to mimic the human eye, for precise measurement of visible light.