Sieves Tyler series

Table 21—Hatch s (1933) Calibration of Four Sieves (Tyler Series) Using...

Tyler Standard Sieve Series Many users case their tests on Tyler standard testing sieves (Table 19-6). The only difference between the U.S. sieves and the Tyler screen scale sieves is the identification method. Tyler screen scale sieves are identified by nominal meshes per linear inch while the U.S. sieves are identified by millimeters or micrometers or by an arbitraiy number which does not necessarily mean the mesh count. The Tyler standard sieve scale series has... 

The sieve is made of a wire mesh cloth of standard sizes held in place by a circular metal frame. The diameter of the sieve ranges from 4 to 18 in., and the height may vary from 1 to 2 in. Three popular sieve series are used the Tyler Series, the first commercial laboratory screens the U.S. Standard Series and the U.S. Alternative Series. Both the U.S. Alternative Series and the Tyler Series designations use the approximate number of opening per linear inch. However, the U.S. Standard Series is the preferred designation and is recommended by the International Standards Organization (ISO). Table 15.3 shows the U.S. Sieve Series and Tyler Series equivalents for a selected number of screens. 

U. S. Sieve Series—A series of sieves, differing but slightly from the Tyler Standard Screen Scale, was proposed in 1919 by the National Bureau of Standards. This has been called the U. S. Sieve Series and in general the sizes advance in the same ratio as the Tyler Screen Scale, but a 1-mm opening is used as a base rather than the opening for the 200-mesh cloth in the Tyler series. There appears to be no reason for preferring one type of series over the other. Table 12 shows the various characteristics of the U. S. Sieve Series adopted by the A.S.T.M. which may be contrasted, with those of the Tyler Screen Series given in Table 11. 

The I.M.M. Series has been superseded by the British Engineering. Standards Association Series (1932). This sieve series is also shown in Table 13. It will be noted that the openings follow closely those of the Tyler series, the differences being due to the desire of specifying British Standard Wire diameters. 

The U. S. Sieve Series does not progress by the same ratio as the Tyler series in every instance. This may be checked by reference to Tables 11 and 12. The U. S. Sieve Series has been widely used in this country, and accepted as the standard by the American Society for Testing Materials. 

Mesh Size 1) The particle size of activated carbon as determined by U.S. Sieve Series 2) The size of particles as measured by the standard Tyler series of screens. 

The smallest mesh size for the Tyler Series is 400 mesh, equivalent to a 38 pm opening, while the smallest mesh size for the U.S. Series is 635 mesh, equivalent to a 20 pm opening. For partieles finer than 20 pm, the surfaee and eleetrostatie forees beeome important, and partiele elassifieation by sieve analysis is not reeom-... 

TABLE 15.3 U.S. Sieve Series and Tyler Equivalents for Selected Screens... 

See also Table 1 showing Comparison of US, Tyler, British and German Sieve Series in Vol 1 of Encycl, p A674... 

Comparison of US, Tyler, British and German Sieve Series... 

It has become the practice to refer to chromatographic supports in terms of the mesh range. When sieving particles for chromatographic columns both the Tyler Standard Screens and the United States Standard Series are frequently used. Tyler screens are identified by the actual number of meshes per linear inch. 

TABLE 12.1. Comparison Table of United States, Tyler, Canadian, British, French, and German Standard Sieve Series... 

Tyler Standard Screen Scale Sieve Series. 

A sieve diameter is defined as the width of the minimum square aperture through which the particle will pass. A common sizing device associated with this definition is a series of sieves with square woven meshes. Two sieve standards, i.e., Tyler Standard and American... 

The common sieves are made of woven wire cloth and have square apertures. The sizes of the sieve openings have been standardized, and currently two different sets of standard series, the Tyler Standard and the U.S. Series ASTM Standard, are used in the United States. The mesh number of a sieve is normally defined as the number of apertures per unit area (square inch). Thus, the higher the mesh number the smaller the aperture. Typical mesh numbers, aperture sizes, and wire diameters are given for the lyier sieves and the U.S. ASTM sieves in Table 1.3. Sieve analysis covers the approximate size range of 37 pm to 5,660 pm using standard woven wire sieves. Electroformed micromesh sieves extend the range down to 5 pm or less while punched plate sieves extend the upper limit. 

Table 1.3. Tyler Standard and U.S. ASTM Sieve Series...

The sample is wet-sieved through a Tyler 300-mesh phosphor-bronze twilled-wire-cloth sieve which passes material finer than 50 /z. All the clay and the finer portion of the silt are washed through the sieve into a 1-liter sedimentation chamber. The silt remaining with the sands is dry-sifted through another 300-mesh Tyler sieve, added to a series of sand sieves. 

Where a closer sizing is required Column 5 shows the Tyler Standard Screen Scale with intermediate sieves. In this series the sieve openings increase in the ratio of the fourth root of 2 or 1.189. 

For closer sizing it is possible to provide a ratio between sieve openings of y/2. The ratio between sizes of the openings is then y/2 or 1.189, and the difference in areas between two successive openings is about ll/2 times instead of 2, as with the Tyler and U. S. series. Reference to Table 11 shows the refinements possible with the use of the y/2 series. 

Efficiency tests with sand and galena were made in the intermediate-size sieves of the Tyler 2 series. In this way the average of the limiting sizes (Tyler /2 series) was almost equal to the size of the opening of the testing sieve, and the ratio of undersize to oversize was about one to one. Thus the condition of the feed in each test was made as difficult as possible. 

Table 20—Moment Method for Computing Average Mesh Size of Crushed Quartz. (Tyler Sieve Series)...

The fineness modulus was developed in an effort to correlate strength of concrete in terms of its component sizes. The fineness modulus is simply the sum of the percentages coarser in a given sieve-analysis divided by 100. In concrete work, fineness modulus is applied to the aggregate and the following Tyler Standard Scale sieves are used 100, 48, 28, 14, 8, 4, and 3/Vin., 3/4-in., and iy2-in. mesh. By using this series of sieves each sieve has a clear width opening double that of the next finest sieve, or one-half that of. the next coarsest sieve. 

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