Sieves nominal dimensions

Fine Series1 — Nominal Dimensions, Permissible Variations, and Limits for Woven Wire Cloth of Standard Sieves... 

The apertures for the British Standard 400 mesh are 37.5 pm with a nominal wire thickness of 26 pm. On the basis of Table 4.1, in which a selection of sieve dimensions are shown, the (nominal) 75 pm sieve has a... 

For particles of regular geometric shape, values of and ip can be calculated readily from the equivalent sphere definition and by Eq. (6.20), as listed in Table 6.2 for a number of geometric solids. However, the catalyst most commonly used in ammonia synthesis is a crushed and classified material which consists of a mixture of irregular particles having linear dimensions defined by the sieves used in the classification. The surface area of individual catalyst particles is very irregular and complex, and does not permit direct measurement or calculation. Consequently, a nominal sphericity factor of 0.65, as reported in the literature for... 

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