The Whatman® Qualitative Filter Paper, Grade 4 manufactured by Whatman is ideal for retention of coarse particles and gel-like precipitates, or for air pollution monitoring where requiring high flow rate. It features very fast filtration speed.
Specification
Material: Cellulose filters, sheets Packaging: Pack of 100 Parameter: 37 sec/100 mL speed (Herzberg), 0.22 psi wet burst W × L: 580 mm × 580 Thickness: 205 μm Ash: ≤0.06% Pore size: 20-25 μm (Particle retention) Basis weight: 92 g/m2