Grade 934-AH: The fine particle retention of this popular grade is superior for its high retention efficiency at high flow rates and its high loading capacity. This is a smooth surface, high-retention borosilicate glass microfiber filter which withstands temperatures over 500 degree C. Used for determining total suspended solids in water, removal of turbidity, and filtration of bacterial cultures. Grade 934-AH is used for a wide range of laboratory applications. It is recommended for water pollution monitoring, cell harvesting, liquid scintillation counting, and air pollution monitoring. Properties: Fast, high loading. Particle retention in liquid (µm): 1.5. Particle retention rating at 98 percent efficiency. Filtration speed herzberg (s): 47. Basis weight(g/m sq): 64.