Ahlstrom pre-weighed and pre-washed filters can save time and resources in your laboratory by providing a convenient solution for your suspended solids testing. Each filter is pre-washed and pre-weighed, following the STM 2540 procedures, and provided in an aluminum pan with the identified weight printed on the pan for ease of use. Ahlstrom Grade 169 is a binder-free microfiber glass filter filter with product stability to over 550 degrees Centigrade. The temperature resistance makes 169 well-suited for use in volatile solids testing as specified in STM2540E. It is designed to both maintain a stable weight at 550°C and exhibit similar handling characteristics before and after 30 minutes in a 600°C furnace. Flow rate: fast. Retention: 1.1 microns.