This Digital Light Meter environment meter is a precision instrument used to measure luminance (footcandles). The meter is fully cosine corrected for the angular incidence of light, meaning that if you are not holding the sensor perfectly perpendicular to the light source, the sensor will still read the light correctly. The sensor is stable and made of a long-life silicon photodiode. The digital light meter accurately measures to 40,000 FC. The meter’s built-in low battery indicator means you’ll never be caught by surprise by a low-power product.