Features The whiteness meter consists of Light Source, Optical System, Detection System, Data Process and Display System. The whiteness Calculation Formula of the instrument is blue light whiteness R457. The optical path design is reasonable, simple. Adopt filter system with correction, the whiteness can be reflected quantitatively. No preheating after starting, measurements can be taken after simple calibration, easy to operate. Able to memory 254 groups of measurement data. Pass strict inspection and testing, the whiteness meter conforms to the JJG 512-2002 Whiteness Meter Verification Regulation. Also conforms to GB3978, GB3979, GB7973, GB7974, ISO2470, GB8904.2, QB1840, GB2913, GB13025.2, GB1543, ISO2471, GB10339, GB5950, GB12911, GB2409 and other standards. Specifications Range：0~120 Resolution：0.1 Illumination Condition：45/0 Illuminant：LED 457nm Whiteness Formula：Blue Light Whiteness WB=R457 Measuring Aperture：≤15 mm Zero Drift：≤0.1 Stability of Display：≤0.5 Repeatability of Measurement：≤0.1 Operating Gondition：Temperature 0~40ºC；Humidity <85%RH Power Supply：4x1.5V AAA(UM-4)Battery Size：Main Unit 156x67x28 mm；Probe Φ44x55 mm Weight：200g(Not Including Batteries) Package Main Unit x 1 External Probe x 1 Standard White Board x 1 Optical Cleaning Cotton Cloth x 1 Carrying Case(B04) x 1 Operation Manual x 1