1、Designation: D 3201 08a1Standard Test Method forHygroscopic Properties of Fire-Retardant Wood and Wood-Based Products1This standard is issued under the fixed designation D 3201; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the y
2、ear 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.1NOTENote 2 was editorially added in October 2009.1. Scope1.1 This test method prescribes the procedure for determin-ing th
3、e moisture content of fire-retardant-treated wood andwood-based product samples after exposure to a standard highrelative humidity condition of 92 6 2 % at 27 6 2C(81 6 4F).1.2 The text of this test method references notes andfootnotes which provide explanatory material. These notes andfootnotes (ex
4、cluding those in tables and figures) shall not beconsidered as requirements of this test method.1.3 The values stated in SI units are to be regarded as thestandard. The inch-pound values given in parentheses are forinformation only and are not considered standard.1.4 This standard does not purport t
5、o 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 Termi
6、nology Relating to Wood and Wood-Based Prod-uctsE 176 Terminology of Fire Standards3. Terminology3.1 DefinitionsDefinitions used in this practice are inaccordance with Terminologies D9and E 176.4. Significance and Use4.1 The hygroscopic properties of wood and wood-basedproducts treated with fire-ret
7、ardant chemicals are often greaterthan for untreated products. This is particularly true at thehigher relative humidity conditions. This higher hygroscopicitysometimes is the cause for staining, decay, poor paint adhesion,and migration and exuding of chemicals and moisture at thehigh humidities. Cor
8、rosion of metal fasteners sometimes alsooccurs.4.2 The results obtained with this standard are important inidentifying treatments with low hygroscopic properties.4.3 Results can be useful in determining exposure limita-tions in service for specific treated products.4.4 Building codes and other speci
9、fications for fire-retardant-treated wood for interior use include requirementsbased on this test method.5. Apparatus5.1 Conditioning chamber with air circulation and capableof being maintained at 27 6 2C (81 6 4F) and a relativehumidity of 92 6 2%.5.2 Oven, air-circulated and vented, capable of mai
10、ntaininga temperature of 103 6 2C (217 6 4F).5.3 Weighing ScaleA scale or balance that will weigh aspecimen within an accuracy of 60.2 %.6. Test Specimens6.1 A minimum of five specimens shall be selected thatrepresent the lot. Unless otherwise specified, specimens shallbe full cross sections, no les
11、s than 25.4 mm (1 in.) along thegrain, but longer as needed to provide a minimum volume of33 000 mm3(2 in.3).6.2 The specimens shall be penetrated by the fire-retardantchemical to be representative for the treated product.NOTE 1The use of untreated specimens as control specimens isrecommended to pro
12、vide verification of the high-humidity conditionsused.1This test method is under the jurisdiction of ASTM Committee D07 on Woodand is the direct responsibility of Subcommittee D07.07 on Fire Performance ofWood.Current edition approved Nov. 1, 2008. Published December 2008. Originallyapproved in 1973
13、. Last previous edition approved in 2008 as D 3201 08.2For 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.1Copyri
14、ght ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.7. Procedure7.1 All measurements of the specimen weight shall be to anaccuracy of 60.2 %.7.2 The specimens shall be in moisture equilibrium with alaboratory ambient condition of 30 to 65 % rel
15、ative humidity orshall be exposed for at least 7 days at such a condition prior tohigh-humidity exposure.7.3 If the specimens will support fungal or mold growthduring the high humidity exposure, then the specimens shall besprayed with a suitable biocide just prior to the above exposureand allowed to
16、 air-dry for the seven days.7.4 Weigh each specimen to obtain weight prior to highhumidity exposure.7.5 Expose all specimens under constant humidity condi-tions of 92 6 2 % at 27 6 2C (81 6 4F) for 7 days.Specimens shall be suitably suspended so that all surfaces areexposed.NOTE 2In this test method
17、, the samples are not exposed for sufficientduration to obtain equilibrium moisture content. This test method wasdeveloped for fire-retardant-treated wood. For the purpose of identifyingtreatments with low hygroscopic properties, the duration of seven days hasbeen shown to be adequate for fire-retar
18、dant-treated wood. If the methodis applied to other materials, the necessity for a longer duration ofexposure needs to be investigated.7.6 If the specimens exude moisture or chemicals or bothunder the exposure conditions, collect any drippings andinclude the weight with the specimen weight.7.7 Weigh
19、 each specimen immediately, after its removalfrom the conditioning chamber to obtain the weight after highhumidity exposure. Observe and record the general appearanceof the specimens.7.8 Dry each specimen in an oven at 103 6 2C(217 6 4F) until approximately constant weight is attained,and reweigh to
20、 obtain ovendry weight after high humidityexposure. Constant weight can be assumed when two consecu-tive readings taken 2 h apart agree within 0.2 %. Avoid dryingfor periods longer than necessary to achieve constant weight,since thermal decomposition of chemical or wood might occurreflecting a highe
21、r than actual moisture content.8. Calculations8.1 Calculate the moisture content of each specimen prior tohigh-humidity exposure (ui) as follows:ui,%5mi modmod!3 100 (1)where:mi= weight of specimen prior to high-humidity expo-sure, andmod= ovendry weight of specimen after high-humidityexposure.8.2 C
22、alculate the moisture content of each specimen afterhigh-humidity exposure (uf) as follows:uf,%5mf modmod!3 100 (2)where:mf= weight of the specimen after high-humidity expo-sure, andmod= ovendry weight of specimen after high-humidityexposure.NOTE 3These methods of determining the moisture content do
23、 notcorrect for any volatilization of chemical during the ovendrying, whichincreases the calculated percent moisture content. Also, the calculation forpercent moisture content is relative to the total specimen weight of woodand chemical. The percent moisture content relative to the wood weightalone
24、is higher and this value can be estimated by reducing the modvaluein the divisor of the above equation by the known or assumed percentageof chemical in the treated specimen.9. Report9.1 Report the following information:9.1.1 Complete identification of the fire-retardant product asto species of wood,
25、 wood product, and treatment.9.1.2 Description of sampling procedure and number anddimensions of test specimens.9.1.3 General description of humidity chamber and controlsused for the test.9.1.4 When data are available for untreated specimensexposed simultaneously with the treated specimens to thehig
26、h-humidity condition, the report shall include the averagemoisture content of the untreated specimens at the end of theexposure.9.1.5 The average of the moisture contents for the treatedspecimens before high-humidity exposure, as calculated by Eq1, shall be reported.9.1.6 The average of the moisture
27、 contents for the treatedspecimens after high-humidity exposure, as calculated by Eq 2,shall be reported.9.1.7 Report any change in the appearance of the specimenduring exposure, including surface wetness, chemical exuda-tion, or crystals on surface.10. Precision and Bias10.1 There is insufficient d
28、ata available to write a precisionand bias statement.11. Keywords11.1 fire-retardant treated wood; hygroscopicity; moisturecontentD 3201 08a12ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of thi
29、s 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 yea
30、rs 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 commit
31、tee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).D 3201 08a13
