【国外标准】 Standard Specification for Electroformed Material and Test Sieves

This specification covers the requirements for design and construction of electroformed sieves. These sieves are used to perform particle-size distribution analysis and in preparing narrowly designated particle-size fractions. They may also be used as reference standards when suitably calibrated. The material used in the manufacture of the sieve sheet shall be nickel or a metal suitable for electrodeposition in a firm crystalline structure. The sheet shall have square or round openings with straight uniform sides and smooth, flat surfaces except for a slight bevel along the edges of the openings. Frames for precision electroformed sieves shall be made from non-corrosive material such as brass or stainless steel, and constructed in such a manner as to be rigid.1.1 This specification covers the technical requirements for design and construction of electroformed sieves and sieve material. These sieves are used to perform particle-size analysis and in preparing narrowly designated particle -size fractions. They may also be used as reference standards when suitably certified. The method of certifying these sieves is included in Annex A1.1.2 The values stated in SI units shall be considered standard for the dimensions of the electroformed mesh openings and the size of the line width in the electroformed mesh. The values stated in inch-pound units shall be considered standard with regard to the sieve frames and to lines per unit length, as in Table 1. The values given in parentheses are mathematical conversions that are provided for informational purposes only, and are not considered standard.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.