ASTM_E_1358_-_97_2013.pdf

Designation:E135897(Reapproved 2013)Standard Test Method forDetermination of Moisture Content of Particulate WoodFuels Using a Microwave Oven1This standard is issued under the fixed designation E1358;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.1.Scope1.1 This test method provides an alternative method toMethod E871,for the determination of the moisture of particu-late wood fuels.Particulate wood fuels are defined in E1126.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.3 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2E871 Test Method for Moisture Analysis of ParticulateWood FuelsE1126 Terminology Relating to Biomass Fuels(Withdrawn2003)33.Summary of Test Method3.1 Moisture is determined by establishing the loss in massof the sample when heated under rigidly controlled conditionsof temperature,time,sample mass,and equipment specifica-tions.44.Significance and Use4.1 This test method provides a rapid determination formoisture in particulate wood fuels in several minutes.Thestandard method,E871,requires a minimum of 18 h.Thismethod is applicable to situations such as the spot-check of themoisture delivered by truck where a quick indication of themoisture of wood delivered is desirable.5.Apparatus5.1 Microwave OvenAny standard commercial micro-wave oven having a power output of at least 600 W can beused.6.Procedure6.1 Obtain a 50 g sample of the wood to be tested usingtechniques outlined in Method E871.6.2 Determine the weight of 3 sheets of standard papertowels placed on top of each other.Record this mass as MT(Mass of Towels).6.3 Place the 50 g sample of the wood on top of the papertowels and determine the mass of the initial sample.Record themass as MSTI(Mass of Sample and Towels Initial).6.4 Place the sample in the microwave and heat on fullpower using the schedule shown in Table 1 for the type ofwood fuel being tested.Remove sample and towels from ovenafter each heating interval,weigh,and stir.When the masschange between successive weighings is less than 0.5 g,recordthis mass as MSTF(Mass of Sample and Towels Final).7.Calculation7.1 Calculate the mass percent moisture in the sample asfollows:Moisture in Sample,%5MSTI2 MT!2MSTF2 MT!/MSTI2 MT!8.Precision and Bias8.1 The following criteria should be used for judging theacceptability of the results:8.1.1 RepeatabilityDuplicate results by the same labora-tory should not be considered suspect unless they differ bymore than 1%.8.1.2 ReproducibilityThe results submitted by two ormore laboratories should not be considered suspect unless theydiffer by more than 1.5%.1This test method is under the jurisdiction of ASTM Committee E48 onBioenergy and Industrial Chemicals from Biomass and is the direct responsibility ofSubcommittee E48.05 on Biomass Conversion.Current edition approved June 1,2013.Published June 2013.Originallyapproved in 1990.Last previous edition approved in 2006 as E1358-97(2006).DOI:10.1520/E1358-97R13.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.4Harris,Robert A.,“Rapid Determination of Wood Fuel Moisture Using aMicrowave Oven for Drying,”Forest Products Journal,Vol 32,No.10,October1982,pp.5659.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 9.Keywords9.1 microwave oven;moisture content;particulate woodfuelsASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard.Users of this standard are expressly advised that determination of the validity of any such patent rights,and the riskof infringement of such rights,are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised,either reapproved or withdrawn.Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters.Your comments will receive careful consideration at a meeting of theresponsible technical committee,which you may attend.If you feel that your comments have not received a fair hearing yo