Whatman Quartz Microfibre Air Sampling Filters
High purity quartz (SiO2) microfibre filters are used for air sampling in acidic gases, stacks, flues and aerosols, particularly at high temperatures up to 500°C and in PM10 testing. Because of the low level of alkalin earth metals, "artifact" products of sulfates and nitrates (from SO2 and NO2) are virtually eliminated. 8 x 10 in. sheets of QM-A type filters are available sequentially numbered according to EPA standards, and are suitable for most applications; QM-B type filters are for use when double thickness and increased strength and retention is required. QM-B type filters are available only in 8 x 10 in. sheets. Circle filters come 100 Filters/Box. Plain 8 x 10 in. sheets come 25 Filters/Box. Pre-numbered 8 x 10 in. QM-A sheets come 100 Sheets/Box.