Historical
ASTM C1121/C1121M-04(2015)
Standard Test Method for Turner and Newall (T and N) Wet-Length Classification of Asbestos
1.1 This test method covers the operation of the Turner and Newall (T and N) wet sieving classifier for asbestos,2 and a procedure for the determination of fiber length distribution and fines (defined in Terminology D2946) content of milled asbestos fiber (−74 μm [200 mesh]) sieve described in Specification E11.
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 D2752/D2752M 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 Standard3 grades 4A to 7D inclusive as determined by Test Method D3639/D3639M.
ASTM International [astm]