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 also have fine particle retention of 1.5 µm at high flow rates to process heavy, turbid samples.
- 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 47mm glass microfiber filter can be measured to five decimal places if needed)
- RTU 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 weighing steps repeated twice for customers with the highest regulatory concern
- Economy versions of 934-AH RTU dissolved, suspended, and volatiles testing filters also available. These filters are pre-washed and dried but not weighed and do not come with barcodes
In addition, the pre-weighed glass microfiber filter papers are packaged with a barcoded aluminum pan noting the filter weight. The barcode from this pan can be used to find documentation of the filter weight on the GE Healthcare Life Sciences website. Each box of 934-AH RTU filters also has a barcode that can be used to download the weights of all filters from that box.