Our Whatman glass microfiber filter papers in grade 934-AH RTU have been pre-washed, dried (or ignited), cooled, desiccated and weighed, which eliminates the pre-treating steps that are otherwise required by the US EPA Laboratory Standard Method 2540 parts C, D, and E. These glass microfiber filter papers have fine particle retention of 1.5 µm at high flow rates to process heavy, turbid samples. Our Whatman filter papers 934-AH family of products come in three different varieties: 934-AH RTU for Suspended and Dissolved Solids—pre-washed, dried, cooled, and weighed filters with certified mass loss between washing and drying steps of the lesser of less than 0.5 mg or 4% in accordance with US EPA Lab Standard Method 2540 parts C and D. (Most filters come weighed to four decimal places, however a version of the 47 mm glass microfiber filter can be measured to five decimal places if needed.) Ready-to-use for Volatiles—pre-washed, pre-weighed and pre-fired at 550°C aligned to US EPA Laboratory Standard Method 2540 parts C, D, and E. RTU Double Weigh—drying, cooling and filter paper weighing steps repeated twice for customers with the highest regulatory concern. Economy versions of 934-AH RTU dissolved, suspended, and volatiles testing filters are also available. These filter papers are pre-washed and dried but not weighed and do not come with barcodes. Watch our 934-AH RTU Whatman filter paper demonstration to learn more. The pre-weighed glass microfiber filter papers are packaged with a barcoded aluminium pan noting the filter paper weight. The barcode from this pan can be used to find documentation of the filter weight on the Cytiva website. Each box of 934-AH RTU filter papers also has a barcode that can be used to download the weights of all filter papers from that box. Looking for a filter paper, membrane filter, or syringe filter? Let Cytiva help you find the optimal filter for your needs to ensure reliable analysis. What are grade 934-AH RTU (ready-to-use) Whatman glass microfiber filter papers used for? Whatman 934-AH ready to use (RTU) glass microfiber filter papers are widely used for dissolved, suspended and volatiles solid analysis. They are also used for a wide range of industrial and environmental water monitoring applications including the monitoring of rivers, lakes and coastal waters, as well as analyzing purified discharge of wastewater treatment plants and monitoring discharge water from industrial plants. Our 934-AH RTU filter papers are available in a variety of dimensions from 42 mm to 90 mm, in packs of 100.