Ahlstrom* Quantitative Grade Filters (Ashless)

These quantitative grades are made from 100% high quality cotton fibers using ultrapure, reverse osmosis water. A final acid treatment removes any remaining organic or inorganic impurities. All ashless quantitative grades have a maximum ash content of 0.007%.

Grade 54: 10 µm
Fast filtering, coarse surface. Used in air analysis, aluminum and zirconium hydroxides, cobalt sulfide and gelatinous particles.
Grade 74: 2.0 µm
Medium flow rate, good retention for filtering trace elements, silver chromate, lead sulfate, zinc and ammonium hydroxides.
Grade 94: 1.5 µm
Fine retention for very fine particles, barium and lead sulfates, stannic and nickel sulfide, calcium oxalate, calcium oxalate, calcium fluoride.