Active Standard ASTM D7430 | Developed by Subcommittee: D05.23
Book of Standards Volume: 05.06
Historical (view previous versions of standard)
Significance and Use
5.1 It is intended that this practice be used to provide a sample representative of the coal from which it is collected. Because of the variability of coal and the wide variety of mechanical sampling equipment available, caution should be used in all stages of the sample collection process, the design of sampling system specifications, the equipment procurement and the acceptance testing of installed equipment.
5.2 After removal from the sampling system and further preparation (Practice D2013), the sample may be analyzed for a number of different parameters. These parameters may define the lot's value, its ability to meet specifications, its environmental impact, as well as other properties.
1.1 This practice is divided into 4 parts. These 4 parts represent the previous standards D7256/D7256M, D4916, D4702, and D6518. These 4 standards are the 4 that govern the mechanical sampling of coal and have been combined into one document for the ease of reference of the users of these standards.
1.2 Part A—Mechanical Collection and Within-System Preparation of a Gross Sample of Coal from Moving Streams—Covers procedures for the mechanical collection of a sample under Classification I-B-1 and I-B-2 (Practice D2234/D2234M) and the within-system preparation (reduction and division) of gross samples utilizing various components of the mechanical sampling system.
1.2.2 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.
1.3 Part B—Mechanical Auger Sampling——Describes procedures for the collection of an increment, partial sample, or gross sample of material using mechanical augers. Reduction and division of the material by mechanical equipment at the auger is also covered. Further manual or mechanical reduction or division of the material elsewhere shall be performed in accordance with Practice D2013.
1.3.1 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.4.2 Spacing of Increments for Cross-Belt and Falling Stream Samplers—Cross-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 practice 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.
1.4.4 It is essential that the inspector have the documentation listed in Section 2 of this practice when conducting an inspection.
1.4.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.5 Part D—Bias Testing of a Mechanical Coal Sampling System—Presents sample collection and statistical evaluation procedures for testing mechanical sampling systems (including auger systems), subsystems, and individual system components for bias. It is the responsibility of the user of this practice to select the appropriate procedure for a specific sampling situation.
1.5.1 Part D does not purport to define an absolute bias. Bias defined by this practice is the difference between the population mean of the mechanical sampler test results and the accepted reference value.
1.5.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.6 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. For a specific hazard statement, see section 16.1.
2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.
D121 Terminology of Coal and Coke
D2013 Practice for Preparing Coal Samples for Analysis
D2234/D2234M Practice for Collection of a Gross Sample of Coal
D4621 Guide for Quality Management in an Organization That Samples or Tests Coal and Coke
D4702 Practice for Quality Management of Mechanical Coal Sampling Systems
D4749 Test Method for Performing the Sieve Analysis of Coal and Designating Coal Size
D4916 Practice for Mechanical Auger Sampling
D6518 Practice for Bias Testing a Mechanical Coal Sampling System
D7256/D7256M Practice for Mechanical Collection and Within-System Preparation of a Gross Sample of Coal from Moving Streams
E105 Practice for Probability Sampling of Materials
E122 Practice for Calculating Sample Size to Estimate, With Specified Precision, the Average for a Characteristic of a Lot or Process
E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods
E456 Terminology Relating to Quality and Statistics
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
ICS Number Code 73.040 (Coals); 75.160.10 (Solid fuels)