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 (<0.01 % according to DIN 54370). 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.
Specifications of the different paper grades
|
| 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).
|
