CENTER-337 hand-held light meter to measure whole range: 0.00 to39990 lux 0.000 to 3999 fc auto-zero operation simple and lightweight automatic transmission illuminometer suitable for use in the case of reading the need for lighting offices, computer rooms, staircases and other walkways safe operating instructions According to the former meter, please read the following instructions and in accordance with the specifications of use - Use of environmental conditions: the height of 2000 meters below the relative humidity: 90% RH Operating temperature: 0-40 ℃ - preservation and cleaning essentials: 1. Non-Manual set out the inspection and maintenance of the Company shall be qualified staff. 2. Regularly wipe with a dry cloth, do not use detergents, solvents to clean the table safety symbols: CE ?: comply with European CE safety norms CENTER-337 light meter (Compact) Product Specifications: Measuring range 0.00 to 39.99 / 399.9 / 3999 / 39990 lx 0.000 to 3.999 / 39.99 / 399.9 / 3999 fc Resolution:? -0.01 lx a 10 lx; ??0.001fc-1fc accuracy of ± 3% rdg ± 5dgts (2856K color temperature calibration standard lamp) Temperature characteristics ± 0.1% / ℃ sampling rate 2.0 times / sec photoreceptor LED operating temperature and humidity 0 ℃ -40 ℃ (32 ℉ -104 ℉)? 0-80% RH Storage temperature and humidity -10 ℃ a 50 ℃ (14 ℉ -122F)? 0- 70% RH overload display "a" shows the power 9V battery x1 (006PorIEC6F220rNEDAl604) Dimensions 196 (L) x54 (w) x33 (H) mm Weight Approx 180g Accessories 9V battery. Instructions