The newly released Sinometer Luxmeter LX1330B is a lux meter with wide measuring range and lots of nice features. A luxmeter is used for checking the level of illuminance, the light falling on a surface, It is defined as: 'the density of the luminous flux incident on a surface'. It is the quotient of the luminous flux by the area of the surface when the latter is uniformly illuminated. - (E = df / dA). This convenient gadget is widely used in many areas such as construction, inspection, photography, greenhouse gardening and etc. The LX1330B can measure from 0 up to 200,000 lux, you can switch the units between lux and footcandle by simply pressing a button. It's powered by a 9V battery, which last for 200 hours or even longer. Other nice features include data hold, auto zero and more. Specifications: Power: 9V x 1, Ranges: 0-200/2,000/20,000/200,000Lux Accuracy: ±3% ±10 digits (±5% ±10 digits as over 20,000Lux) Repeatability: ±2% Temperature Characteristic: ±0.1%C Photo detector type: Silicon Photo Diode with Filter Operating temperature: 32-104 degrees F (0-40 degrees C) Sampling rate: 2-3 times per second Battery life: 200 hours (estimate) What's in the box: Sinometer Luxmeter LX1330B Carrying case 9V battery User manual.