- 中文主题词：试样 ; 抽样方法 ; 燃料 ; 检验 ; 导则 ; 标准 ; 固体燃料 ; 煤
- 标准号：ASTM D4702-2004
- 发布日期：2004
- 英文题名：Standard Guide for Quality Management of Mechanical Coal Sampling Systems
- 英文主题词：coal sampling ; inspection ; mechanical sampling ; sampling systems
- 标准状态：现行
- 发布单位：US-ASTM
- 载体形态：6P.;A4
- 中国标准分类号：D21
- 国别：美国材料与试验协会
1.1 This guide is applicable to cross-belt, falling stream, and auger sampling systems.
1.2 Spacing of increments pertains to the kind of interval between increments. Intervals can be defined in quantitative terms, such as units of time or mass, or in terms of position over the lot.
1.2.1 Spacing of Increments for Cross-Belt and Falling Stream SamplersCross-belt and falling stream type mechanical sampling systems take increments based on time, either at fixed time intervals or at random times during a fixed time strata. Some falling stream samplers can take increments based on equal mass of coal sampled as determined by scales. The sections of this guide that pertain to cross-belt and falling stream samplers describe procedures for only time-based sampling systems. This time-based inspection guideline will satisfy most criteria for mass-based or combination mass-based and time-based sampling systems. If there are items that are not covered, the inspector should refer to the manufacturer''s literature.
1.2.2 Spacing of Increments for Auger SamplingThe spacing of increments collected by auger sampling systems is defined in terms of position over the lot.
1.3 It is essential that the inspector have the documentation listed in Section of this guide when conducting an inspection.
1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
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 and health practices and determine the applicability of regulatory limitations prior to use.