What is a footcandle?

A unit of measurement indicating how much illumination is reaching a surface.  more

A unit of measurement indicating how much illumination is reaching a surface. It is equal to one lumen striking an area of one square foot. What is a candela? A candela is a unit of measure indicating the luminous intensity (candlepower) of a light source in a specific direction; any given light source will have many different intensities, depending upon the direction considered. Why should I be concerned about the mercury content of lamps? Mercury is a highly persistent and toxic chemical that is building up to dangerous concentrations in fish, wildlife, and human beings throughout the US. By choosing high-efficiency lamps that contain less mercury, you help reduce the environmental impacts and health risks of lamp breakage during use, transport, and disposal. What is the proper disposal of fluorescent light bulbs? See www.lamprecycle.  more