ASTM_D_4442_-_15.pdf

Designation:D444215Standard Test Methods forDirect Moisture Content Measurement of Wood and Wood-Based Materials1This standard is issued under the fixed designation D4442;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.This standard has been approved for use by agencies of the U.S.Department of Defense.1.Scope1.1 These test methods cover the determination of themoisture content(MC)of wood,veneer,and other wood-basedmaterials,including those that contain adhesives and chemicaladditives.The test methods below describe primary(A)andsecondary(B through D)procedures to measure moisturecontent:Method APrimary Oven-Drying MethodMethod BSecondary Oven-Drying MethodMethod CDistillation(Secondary)MethodMethod DOther Secondary Methods.1.2 The primary oven-drying method(Method A)is in-tended as the sole primary method.It is structured for researchpurposes where the highest accuracy or degree of precision isneeded.1.3 The secondary methods(B through D)are intended forspecial purposes or under circumstances where the primaryprocedure is not desired or justified.In these procedures,moisture content values cannot be reported with an accuracygreater than integer percentage values.However,a greaterlevel of accuracy may be reported if the appropriate primaryprocedures are used.1.4 Distillation(secondary)method is intended for use withmaterials that have been chemically treated or impregnatedsuch that the oven-drying procedures introduce greater errorthan desired in the results.1.5 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:2D9 Terminology Relating to Wood and Wood-Based Prod-uctsD4933 Guide for Moisture Conditioning of Wood andWood-Based Materials3.Terminology3.1 Definitions:3.1.1 For definitions of terms used in this test method,referto Terminology D9.3.1.2 moisture contentthe amount of water contained inthe wood,usually expressed as a percentage of the mass of theoven-dry wood(in accordance with Terminology D9).3.1.2.1 DiscussionThe moisture content of wood or otherwood-based materials can be expressed either as a percentageof oven-dry mass of the sample(oven-dry basis)or as apercentage of the original mass(wet basis).The methodsdescribed in this standard refer to the oven-dry basis.Becauseoven-dry mass is used,moisture content values may exceed100%.The term moisture content when used with wood orother wood-based materials can be misleading since theyfrequently contain varying amounts of volatile compounds(extractives that are evaporated when determining moisturecontent).Definition of the moisture content of wood is furthercomplicated when determined by a thermal method because ofthermal degradation,which causes the final moisture-free massto decrease from small but continuous losses.4.Significance and Use4.1 Moisture content is one of the most important variablesaffecting the properties of wood and wood-based materials.The procedures in these test methods are structured to permitthe full range of use from fundamental research to industrialprocessing.Method A is designed for obtaining the mostprecise values of moisture content consistent with the needs of1These test methods are under the jurisdiction of ASTM Committee D07 onWood and are the direct responsibility of Subcommittee D07.01 on FundamentalTest Methods and Properties.Current edition approved June 1,2015.Published August 2015.Originallyapproved in 1984.Last previous edition approved in 2007 as D4442 07.DOI:10.1520/D4442-15.These test methods replace,in part,Test Methods D2016,for Moisture Contentof Wood,discontinued 1989.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 the user.It also provides means of assessing variabilitycontributed by the oven or specimen hygroscopicity,or both.Inaddition,criteria are described for defining the endpoint inoven-drying.Method A is the reference(primary)standard fordetermining moisture content of wood and wood-based mate-rials.Methods B through D are secondary methods to permitrelatively simple procedures of measuring moisture content,but with less precision than Method A.However,greaterprecision may be obtained with supporting data by using theappropriate procedures in Method A.5.Method AOven-Drying(Primary)5.1 Apparatus:5.1.1 Ove