【国外标准】 Standard Test Method for Fineness of Hydraulic Cement and Raw Materials by the 300-μm (No. 50), 150-μm (No. 100), and 75-μm (No. 200) Sieves by Wet Methods

This test method covers wet sieving techniques for determination of fineness of hydraulic cement and raw materials by means of the No. 50, No. 100, and No. 200 sieves. The following apparatus shall be utilized: wet test sieves; spray nozzle; pressure gage; balance; weights; brush; dry test sieves; and NBS SRM No. 1004 (glass bead standard). Dry sieve standardization shall be performed by determining the correction factors and by preparing the standard samples. Wet sieve calibration shall follow and shall utilize the sieve correction factor. The procedure for wet sieving shall include the following: weighing of the sample; recording the weight and transferring the sample quantitatively to a clean dry sieve; wetting the sample thoroughly with a gentle stream of water; removing the sieve from under the nozzle and adjusting the pressure of the spray nozzle; returning the sieve to its position under the nozzle and washing it; moving the sieve in the spray with a circular motion; rinsing the sieve with distilled or deionized water immediately after removing it from the spray; blotting the lower surface of the screen cloth with a damp, clean cloth; drying the sieve and residue in an oven or over a hot plate; cooling the sieve; brushing the residue from the sieve; and weighing the sieve on a balance.1.1 This test method covers wet sieving techniques for determination of fineness of hydraulic cement and raw materials by means of the 300-μm (No. 50), the 150-μm (No. 100), and the 75-μm (No. 200) sieves.1.2 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. Values in SI units [or inch-pound units] shall be obtained by measurement in SI units [or inch-pound units] or by appropriate conversion, using the Rules for Conversion and Rounding given in IEEE/ASTM SI 10 of measurements made in other units. Values are stated in SI units when inch-pound units are not used in practice.1.3 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.