Over deze norm
1.1 This test method covers the operation of the Turner and Newall (T and N) wet sieving classifier for asbestos, and a procedure for the determination of fiber length distribution and fines (defined in Terminology ) content of milled asbestos fiber (−74 μm [200 mesh]) sieve described in Specification .
1.2 For purposes of estimating length distribution, the test is limited to samples free from excessive quantities of non-fibrous particles or contaminants. Quantities exceeding 0.05 g retained in any given length fractions are considered excessive.
1.3 For comparisons between different fiber grades, only those specimens which have approximately the same degree of fiberization as determined by Test Methods will give completely meaningful results.
1.4 This test method is not applicable to ultrafine grades of asbestos powders which contain little or no fibers retained on a 74-μm [200 mesh] sieve. This method is restricted to Quebec Standard grades 4A to 7D inclusive as determined by Test Method .
Note 1: This is an alternative procedure to Test Method .
1.5 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.
1.6 Warning—Breathing of asbestos dust is hazardous. Asbestos and asbestos products present demonstrated health risks for users and for those with whom they come into contact. In addition to other precautions, when working with asbestos-cement products, minimize the dust that results. For information on the safe use of chrysoltile asbestos, refer to “Safe Use of Chrysotile Asbestos: A Manual on Preventive and Control Measures.”
1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For a specific hazard statement, see .
|Engelse titel||Standard Test Method for Turner and Newall (T and N) Wet-Length Classification of Asbestos|