ProWeigh DoubleWeigh filters are 1.5um Binderless Glass Fiber Filters with all preparation steps done for you! Decrease sample prep time for your suspended solids testing. Includes access to full documentation of the weighing steps to show stability. The Filter ID Number and the original filter weight obtained are printed in numeric and bar code format on the individual pan label. All ProWeigh filters are prepared according to Standard Methods requirements. According to Method 2540 D, binderless glass fiber filters are washed 3 times in deionized water, dried at 103 - 105 degrees C, and weighed to 0.1mg. The drying and weighing steps are then repeated to guarantee weight stability.