Buchner Funnels, Pyrex®. With flat sintered glass filter disc.
Porosity Gradings for Sintered Glassware
| Grade | ISO4793 Designation | Pore Size Index, µm |
| 0 | P250 | 160 to 250 |
| 1 | P160 | 100 to 160 |
| 2 | P100 | 40 to 100 |
| 3 | P40 | 16 to 40 |
| 4 | P10 | 10 to 16 |
Buchner Funnels, Pyrex®. With flat sintered glass filter disc.
Porosity Gradings for Sintered Glassware
| Grade | ISO4793 Designation | Pore Size Index, µm |
| 0 | P250 | 160 to 250 |
| 1 | P160 | 100 to 160 |
| 2 | P100 | 40 to 100 |
| 3 | P40 | 16 to 40 |
| 4 | P10 | 10 to 16 |