The Amprobe LM-120 light meter measures the visible light from fluorescent, metal halide, high-pressure sodium or incandescent sources. It is a portable, easy-to-use digital light meter designed for simple one-hand operation reading in Lumen (lux) or footcandle (fc) units. The LM-120 measures a wide range of light up to 20,000 fc or 200,000 lux with an accurate, high resolution of 0.01 fc/lux. This unit is Autoranging plus manual ranging with ability to Zero out the reading before taking a measurement. Use the LM-120 light meter to measure the illumination level in the interior and to switch off or reduce or increase the output level of lighting fixtures. Reduce the energy burden of the building by significantly increasing the efficiency of its lighting system. One lux is the illumination from a one candela lamp perpendicular to a surface one meter squared at a distance of one meter. One fc is the illumination from a one candela lamp perpendicular to a surface one foot squared at a distance of one foot. 1 foot-candle = 10.764 Lux and 1 lux = 0.09290 footcandles