This 100Pcs/Set fast speed quantitative filter paper are used when you are generally concerned about what is left on the filter. Quantitative filters are used for gravimetric analysis or filtration where the precipitate is to be recovered, which is also concerned about the quantity of substance that remains on the filter; Specification: Material:Cotton Fiber; Filter Type:Quantitative Filter; Filter Speed:Fast Speed (<35s); Ma*. Aperture Diameter:20-25um; Ash Content:?��10.01%; Quantitative Filter Area:80?����4g/m2; Quantity:100Pcs/Set; Size:(Filter Diameter); 1: 7cm; 2: 9cm; 3: 11cm; 4: 12.5cm; 5: 15cm; 6: 18cm; ; Feature: 1. 100Pcs/Set quantitative filter paper, fast speed; 2. With numerous small holes on its surface made from cotton fiber, it only allows liquid particles to pass through while solid materials with large volume Note: 3. Light weight, convenient to use and carry, accurate testing; 4. It requires less filtration time than filter paper with medium and slow speed; 5. It covers a wide range of laboratory applications, which is frequently used for clarifying liquids; 6. It is widely used for gravimetric analysis or filtration where the precipitate is to be recovered; 7. It is suitable for precise quantitative analysis since there is little remaining ash which has little effect on the analysis results. The amount of ash produced after ashing does not e*ceed 0.0009%; Note: You are supposed to make a distinction between quantitative filter paper and qualitative filter paper and choose the proper one according to your requirement; 1. The quantitative filter paper is used for gravimetric analysis or filtration where the precipitate is to be recovered, for e*ample from a Buchner funnel filtration under vacuum; The amount of ash produced after ashing does not e*ceed 0.0009%; 2. The qualitative filter paper is used for qualitative techniques to identify materials. They do not offer the same level of precipitate recovery as quantitative filter paper; The amount of ash produced after ashing does not e*ceed 0.13%; Package Include: 1*100Pcs/Set Quantitative Filter Paper