ASTM_D_7430_-_15b.pdf

Designation:D743015bStandard Practice forMechanical Sampling of Coal1This standard is issued under the fixed designation D7430;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.INTRODUCTIONAnalysis data obtained from coal samples are used in establishing price,controlling mine andcleaning plant operations,allocating production costs,and determining plant or component efficiency.The task of obtaining a sample of reasonable weight to represent an entire lot presents a number ofproblems and emphasizes the necessity for using standard sampling procedures.Coal is one of the most difficult of materials to sample,varying in composition from noncombus-tible particles to those which can be burned completely,with all gradations in between.The task isfurther complicated by the use of the analytical results,the sampling equipment available,the quantityto be represented by the sample,and the degree of precision required.This practice gives the overall requirements for the collection and within-system preparation of coalsamples through the use of mechanical sampling systems utilizing falling stream,cross belt and augerdesigns.This practice also gives the overall requirements for the bias testing and quality managementof mechanical coal sampling systems.The wide varieties of coal-handling facilities preclude thepublication of detailed procedures for every sampling situation.The proper collection of the sampleinvolves an understanding and consideration of the physical character of the coal,the number andweight of increments,and the overall precision required.1.Scope1.1 This practice is divided into 4 parts.These 4 partsrepresent the previous standards D7256/D7256M,D4916,D4702,and D6518.These 4 standards are the 4 that govern themechanical sampling of coal and have been combined into onedocument for the ease of reference of the users of thesestandards.Part A1.2 Part AMechanical Collection and Within-SystemPreparation of a Gross Sample of Coal from Moving StreamsCovers procedures for the mechanical collection of a sampleunder Classification I-B-1 and I-B-2(Practice D2234/D2234M)and the within-system preparation(reduction anddivision)of gross samples utilizing various components of themechanical sampling system.1.2.1 Part A describes mechanical sampling procedures forcoals(1)by size and condition of preparation(for example,mechanically cleaned coal or raw coal),and(2)by samplingcharacteristics.1.2.2 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.The values stated ineach system may not be exact equivalents;therefore,eachsystem shall be used independently of the other.Combiningvalues from the two systems may result in non-conformancewith the standard.Part B1.3 Part BMechanical Auger SamplingDescribes proce-dures for the collection of an increment,partial sample,orgross sample of material using mechanical augers.Reductionand division of the material by mechanical equipment at theauger is also covered.Further manual or mechanical reductionor division of the material elsewhere shall be performed inaccordance with Practice D2013.1.3.1 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1This practice is under the jurisdiction of ASTM Committee D05 on Coal andCoke and is the direct responsibility of Subcommittee D05.23 on Sampling.Current edition approved Nov.1,2015.Published November 2015.Originallyapproved in 2008.Last previous edition approved in 2015 as D743015A.DOI:10.1520/D7430-15B.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 Part C1.4 Part CQuality Management of Mechanical Coal Sam-pling SystemsIs applicable to the quality management ofcross-belt,falling stream,and auger sampling systems.1.4.1 Spacing of increments pertains to the kind of intervalbetween increments.Intervals can be defined in quantitativeterms,such as units of time or mass,or in terms of positionover the lot.1.4.2 Spacing of Increments for Cross-Belt and FallingStream SamplersCross-belt and falling stream type mechani-cal sampling systems take increments based on time,either atfixed time intervals or at random times during a fixed timestrata.Some falling stream samplers can take increments basedon equal mass of coal sampled as determined by scales.Thesections of this practice that pertain to cross-belt and fallingstream samplers describe procedures for only time-basedsampling systems.This time-based inspection guideline willsatisfy most criteria for mass-based or combination mass-basedand time-based sampling systems.If there are items that are notcovered,the inspector should refer to the manufacturersliterature.1.4.3 Spacing of Increments fo