Ambient light sensor focuses on intelligent daylight harvesting for commercial lighting

April 16, 2012 // By Paul Buckley
Austriamicrosystems has introduced at the Light+Building exhibition in Frankfurt, Germany, the company’s TSL4531 ambient light sensor device family, which enables daylight harvesting for intelligent lighting systems and luminaires.

The sensor family – developed by TAOS, the leading global supplier of intelligent light sensors acquired by austriamicrosystems in 2011 – offers a wide sensitivity range from 3 lux to 220,000 lux, preventing saturation even in direct sunlightwhile implementing a photopic response model that spectrally matches light perception in the human eye.

The TSL4531 ambient light sensor provides a simple, direct lux output and a 16-bit digital interface. Sophisticated filters automatically reject the 50-60 Hz ripple typically produced by a building’s fluorescent lighting systems, enabling the sensed light levels to more accurately measure the daylight that is entering the building.

Daylight harvesting is the next major step in the development of integrated lighting systems, enabling luminaires to dim in response to the amount of outside light that is entering a building through windows or skylights. By supplementing the working space with only the amount of light needed to maintain a uniformly lit environment, energy savings of 30% or more can be realized when compared to existing installations which do not respond to changes in ambient light.

Being fully aware of the lit environment also allows optimization that extends beyond energy savings. In integrated building management and control systems, the combination of proximity/motion and light sensing provides an abundance of data concerning the interior environment. Additionally, daylight sensing/harvesting combined with precise control mechanisms enable the lighting system to deliver not just the needed amount of light, but also offers the ability to tune the type of light to suit the activity and users in a particular space. Environmentally aware, decision-directed, multi-sensor networks and optimized light will enhance not only the productivity of the built space, but also worker and group productivity, as well as increasing the health and well-being of individuals.

The TSL4531 features a direct lux output with a wide dynamic range of 3 lux to 220,000 lux and approximates the human eye’s spectral response in diverse lighting conditions.