This KERRO KWM-1 instrument is based on the principle of photoelectric effect & D65 light source (R457) and with 45/0 as a illumination condition Meanwhile, except solution or liquid samples, instrument can be widely measured the whiteness value of any substances. KERRO KWM-1 is a portable hand-held battery-powered whiteness meter used to measure the brightness level of paper, cardboard, cellulose, pulp, textiles, paint, enamel, plastic, porcelain, cement, concrete, building materials, chemicals, powders, talc, starch, flour, salt, detergents, cosmetics, linen and other non-metal substances.