Lab Products


Quantitative Filter Papers


Ultramicro balances Cubis®
 


These filter papers are made of refined pulp and linters with over 98% alpha-cellulose content. They are guaranteed to be free of any residual acids and they have an extremely low percentage of ash content As a result, these filters are virtually ash-free. All Sartorius ashless filter papers are characterized by high wet strength and high purity and are therefore especially suitable for quantitative analysis, Buechner funnels, pressure or vacuum filtration. They are available in different formats as in rolls, sheets, discs and folded filters.
Color-doted dot Grade Precipitation Properties g/m² Particle retention (µm) Filtration rate (s)
Black dot 388 Coarse crystalline Wide-pored,spongy structure, high rate of filtration 84 12-15 10
White dot 389 Medium-fine crystalline Medium-wide-pored, medium-fast rate of filtration 84 8-12 20
Yellow dot 389F Medium-fine crystalline Medium-wide-pored, medium-fast rate of filtration, low-fat content 84 8-12 20
Red dot 392 Fine crystalline Medium density, moderately fast rate of filtration 84 5-8 50
Green dot 390 Fine crystalline Narrow-pored, dense, slow rate of filtration 84 3-5 100
Blue dot 391 Very fine crystalline Fine-pored, highly dense, very slow rate of filtration 84 2-3 180
Purple dot 393 Very fine crystalline extra fine-pored and dense, very slow rate of filtration 100 1-2 300
Filtration rate
The time required to filter 10 ml of distilled water at 20°C through a free-hanging, fully-wetted disc filter with a diameter of 110 mm folded in quarters. Expressed in seconds (per mm).