IS 11267:1985 is the Indian Standard (BIS) for method of test for length distribution (wet classification of fibre length) of chrysotile asbestos fibre using turner and newall classifier. This standard specifies the method for determining the length distribution of chrysotile asbestos fibres through a wet classification process. It details the procedure using a specialized apparatus known as the Turner and Newall classifier. This test is critical for grading asbestos fibres, which directly impacts the properties of asbestos-cement products.
Method of test for length distribution (wet classification of fibre length) of chrysotile asbestos fibre using Turner and Newall classifier
| Parameter | IS Value | International | Source |
|---|---|---|---|
| Specified Apparatus | Turner and Newall water classifier | Bauer-McNett classifier | ASTM D2589-88 |
| Test Sample Mass | 20 ± 0.05 g | 10 ± 0.05 g | ASTM D2589-88 |
| Water Flow Rate | 25 ± 0.5 litres/min | 5.7 ± 0.3 gal/min (~21.6 ± 1.1 litres/min) | ASTM D2589-88 |
| Test Duration | 10 minutes | 20 minutes | ASTM D2589-88 |
| Number of Classifier Tanks | 4 | 4 (standard) | ASTM D2589-88 |
| Finest Screen Mesh | 75-micron IS Sieve | U.S. Sieve No. 200 (75 µm) | ASTM D2589-88 |
| Coarsest Screen Mesh (Tank 1) | 1.18-mm IS Sieve | U.S. Sieve No. 4 (4.75 mm) or No. 14 (1.40 mm) depending on grade | ASTM D2589-88 |