Paper board water absorptiveness tester measures the surface water absorption of paper and paper board. Loose paper, e.g. newsprint, unsized paper, e.g. blotter and other high absorbability paper is not for this tester. Paper board water absorptiveness tester principle The Cobb value of surface water absorption of paper and paperboard.: The calculated mass of water absorbed in a specified time by a unit area of paper or board under specified pressure and temperature conditions. It is expressed in g/㎡. C=（G2-G1）×100。 C-water absorptiveness G2-wet mass, in grams, of the test piece G1-dry mass, in grams, of the test piece When Cobb value is less than 200～250 g/㎡ for single layer, more layers can used. Paper board water absorptiveness tester technical data Metal roller sectional area: 100±0.2㎝2 Metal roller diameter: 112.8±0.2mm Roll height：50mm Blotting paper: 200～250g/㎡ Absorption speed: 75mm/10min Smooth metal roller: length 200±0.5mm，mass10±0.5kg。 Water volume: 100mm±5ml。 Dimension: 480×400×420（mm） Weight: 28kg Standard ISO 535，GB/T 1540，QB/T 1668