1、Designation: F3340 18Standard Test Method forThermal Resistance of Camping Mattresses Using aGuarded Hot Plate Apparatus1This standard is issued under the fixed designation F3340; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the
2、 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 covers the measurement of the thermalresistance of camping mattresses in conditions of stead
3、y-stateheat transfer, using a two-plate apparatus. The camping mat-tress is held under constant compressive force between aguarded hot plate and a cold plate. The primary heat transferfor this method is one dimensional, vertically through thecamping mattress thickness. As such this measured thermali
4、nsulation value is a repeatable comparative measurement.However, it should be noted that this value may not alwayscorrelate to actual insulation performance as real-world heattransfer may differ slightly because of additional heat lossespossibly involved (for example, edge heat loss, uncoveredsurfac
5、e heat loss, compression rate changes or posture changesduring sleep).1.2 This test method is applicable to all types of campingmattresses (for example, inflating air mattress with or withoutinsulation, inflating air mattress with reflective materials,self-inflating open cell foam mattress with or w
6、ithout coring,closed cell non-inflatable foam mats). Auxiliary insulation ofany type shall be excluded in the measurement. Auxiliaryinsulations are any type of material removable from themattress (for example, sleeping bags, mattress covers).1.3 The sample thickness shall not exceed the limit deter-
7、mined by the hot plate dimensions stated in 7.1.2.1.4 UnitsThe values stated in SI units are to be regardedas the standard. No other units of measurement are included inthis standard.1.5 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is there
8、sponsibility of the user of this standard to establish appro-priate safety, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.6 This international standard was developed in accor-dance with internationally recognized principles on standard-
9、ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2C168 Terminology Relating to Thermal InsulationC17
10、7 Test Method for Steady-State Heat Flux Measure-ments and Thermal Transmission Properties by Means ofthe Guarded-Hot-Plate ApparatusD1518 Test Method for Thermal Resistance of BattingSystems Using a Hot PlateE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE691 Practice for
11、Conducting an Interlaboratory Study toDetermine the Precision of a Test Method2.2 ISO Standard:3ISO 8302 Thermal insulation Determination of steady-state thermal resistance and related properties Guardedhot plate apparatus3. Terminology3.1 DefinitionsFor definitions of terms used in this testmethod,
12、 refer to Terminology C168 and 3.2.3.2 Definitions of Terms Specific to This Standard:3.2.1 ambient air speed, nthe air speed of environmentimmediately surrounding the specimen and apparatus.3.2.2 ambient temperature, nthe air temperature of envi-ronment immediately surrounding the specimen and appa
13、ratus.3.2.3 cold plate, nisothermal boundary created by a rigidcooling plate that contacts one side of the specimen and isparallel to the hot plate.1This test method is under the jurisdiction of ASTM Committee F08 on SportsEquipment, Playing Surfaces, and Facilities and is the direct responsibility
14、ofSubcommittee F08.22 on Camping Softgoods.Current edition approved Oct. 1, 2018. Published November 2018. DOI:10.1520/F3340-18.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume informatio
15、n, refer to the standards Document Summary page onthe ASTM website.3Available from International Organization for Standardization (ISO), ISOCentral Secretariat, BIBC II, Chemin de Blandonnet 8, CP 401, 1214 Vernier,Geneva, Switzerland, http:/www.iso.org.Copyright ASTM International, 100 Barr Harbor
16、Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations
17、 issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.13.2.4 guarded hot plate, nconstant temperature heatsource that consists of a central metering plate and primaryguards surrounding the sides and backside of the meteringplate.3.2.5 guards (thermal guards), nmeans to
18、prevent lateraledge heat loss and promote one-dimensional heat flow in thevertical direction through the test sample.3.2.5.1 DiscussionThe guards consist of a thermal guardring surrounding the metering plate and a backplate (counter-heating plate) parallel to the metering plate. The guards areheated
19、 independently to maintain the same surface temperatureas the metering plate surface temperature.3.2.6 homogeneous mattress, na camping mattress withthe same composition, average density, and distribution ofmaterials and construction method throughout.3.2.6.1 DiscussionThis includes mattresses const
20、ructed ofa repeating pattern in which the length scale of the pattern isless than half of the width of the metering plate. If it is unclearwhether the mattress meets these requirements, consider it anon-homogenous mattress for the purposes of testing.3.2.7 metering plate, nmeasurement region of the
21、guardedhot plate that is controllable to a constant temperature andcapable of measuring heat loss from its surface in the form ofpower.3.2.8 non-homogeneous mattress, na camping mattresswhere the composition, average density of materials, andconstruction method vary from location to location.3.2.9 R
22、-value, nthermal resistance of a material or asystem in inch-pound units: F ft2h/Btu.3.2.9.1 DiscussionR-value is only used as a presentationof a converted final materials RSI-value. It shall not be used inany intermediate measurement data conversion or machinecalibration.3.2.10 RSI-value, nthermal
23、resistance of a material or asystem in SI units: K m2/W.3.2.11 two-plate guarded hot plate apparatus, napparatusthat measures the heat transmission through a specimen fromthe guarded hot plate to the cold plate.4. Summary of Test Method4.1 The specimen is compressed horizontally between aguarded upp
24、er hot plate and a lower cold plate. If inflatable, thespecimen is inflated to a predetermined internal pressure. Thehot plate and cold plate are maintained at fixed temperatures.The ambient temperature is controlled to be equal to theaverage temperature of the hot plate and cold plate. The heatflux
25、 through the specimen is measured during steady-statecondition. The thermal resistance is calculated by dividing thetemperature difference with the heat flux (see Eq 1).5. Significance and Use5.1 The thermal resistance of camping mattresses is animportant indicator of insulation performance. This te
26、stmethod establishes criteria to measure this property consis-tently and in conditions relevant to the application. Themeasured value can be used for evaluating the thermal insula-tion performance of the camping mattresses, thus assisting withthe product construction and design and providing guidanc
27、e forconsumers in comparing and selecting a mattress.6. Interferences6.1 Departures from the procedures and conditions of thistest method may lead to significantly different test results. It isnecessary to report any departures from the procedures andconditions of this test method with the results.6
28、.2 DiscussionTechnical knowledge concerning thetheory of heat transfer, temperature measurement and testingpractices is important for controlling test variables. The causesof measurement uncertainty and variation (Annex A1) shall beunderstood so that any known errors are corrected or elimi-nated to
29、the extent possible, and the system is accuratelycalibrated to ensure measurement accuracy and precision aresatisfactory.7. Apparatus7.1 DescriptionThe apparatus consists of a guarded hotplate, a cold plate, a compression system, a power source,temperature sensors, and a controller. Fig. 1 illustrat
30、es thegeneral assembly of the apparatus. Subsections 7.2 to 7.5describe requirements for each part of the apparatus. Theapparatus shall meet the stated tolerance in Section 8 followingprocedures set forth in Annex A2.7.1.1 The guarded hot plate and cold plate shall be designedand constructed using p
31、rinciples and construction which arewell defined in Test Method C177, Test Method D1518, or ISO8302. Existing guarded hot plate machines compliant to thosestandards, that also meet the requirements described in 7.2 and7.3, can be successfully converted to the apparatus of thisstandard by adding a co
32、mpression system.7.1.2 Additional design consideration shall be given to themaximum specimen thickness limit. Maximum testable speci-men thickness depends on plate construction and dimensions.As such, maximum testable thickness shall be stated on all testreports for a given test apparatus. If a test
33、 sample exceeds themaximum testable thickness, it shall be excluded for testing onthat apparatus. Maximum thickness is determined by using theformula in Section 2.2.1 of ISO 8302 and a 0.5 % threshold ofedge heat loss error (see Annex A4).7.2 Guarded Hot Plate:7.2.1 Metering PlateThe heater shall pr
34、ovide uniformtemperature across the metering plate surface with a variationof less than 0.2C when testing materials of Rctgreater than 0.1Km2/W. The surface of the metering plate shall have anemissivity of 0.9 (as measured at ambient temperature) orgreater as to mimic the emissivity of human skin. T
35、heminimum dimension of the metering plate shall be 200 mm perside if square, or 200 mm in diameter if circular. The maximumheating capacity is designed to provide adequate heat flux andaccuracy in the entire measurable range.7.2.2 Thermal Guard RingThe combined size of thethermal guard ring and mete
36、ring plate shall be between 400 and660 mm per side if square, or between 400 and 660 mm indiameter if circular, to accommodate most standard campingmattresses. The material and construction of the thermal guardring shall be the same as that of the metering plate. The averageF3340 182temperature diff
37、erence between the metering plates surfaceand guard rings surface shall not exceed 0.2C. The surface ofthe guard ring shall have an emissivity of 0.9 (as measured atambient temperature) or greater as to mimic the emissivity ofhuman skin.7.2.3 Counter-Heating PlateThe counter-heating plateshall have
38、a larger surface area than the metering plate regionto effectively prevent from any backside heat loss. The averagetemperature difference between the surfaces of metering plateand lower guard shall not exceed 0.2C.7.3 Cold PlateThe cold plate has the same size as thecombined size of the thermal guar
39、d ring and metering plate.The cold plate temperature control may be achieved using anyviable method, such as thermal electrical cooling andFIG. 1 Two-Plate Guarded Hot Plate Apparatus for Testing Camping MattressesF3340 183temperature-controlled circulating coolant fluids. The tempera-ture differenc
40、e across the cold plates surface that is in the areaequivalent and opposite the metering plate shall be less than0.2C when testing materials of Rctgreater than 0.1.7.4 Compression System:7.4.1 A means shall be provided for imposing a reproduc-ible compression on the specimen. Compression can beachie
41、ved by any viable means, such as dead weight orconstant-force springs.7.4.2 The hot plate and cold plate working surfaces shall beparallel within 2 %.7.5 Supporting FrameTo test a full-size camping mattress,supports shall be provided outside the measurement area toprevent the mattress from bending u
42、nder its own weight.Bending may decrease accuracy of results by distorting thespecimen at or near the testable area. Supports shall be leveledwith the upper surface of the cold plate to keep the mattressflat.8. Calibration and Standardization8.1 The apparatus shall be calibrated annually with NISTst
43、andard reference materials specified in Annex A2. Afterfollowing the procedure in Annex A2, the minimum andmaximum tolerances of the measured value shall be between3 and +1 % of the target standard value.8.2 Calibration of the temperature sensors and heaters shallbe performed regularly according to
44、the manufacturersinstructions, and at any time the accuracy is found to be outsidethe tolerances.9. Sampling and Specimen Preparation9.1 SamplingTest three identical specimens. Any depar-ture shall be noted in the test report.9.2 Specimens:9.2.1 Full-Size SpecimenFull-size samples are mattressesin t
45、he size and shape as used by the end consumer. Full-sizesamples, identical to the final design and construction ofproduction model, shall be used for any consumer-facingclaims that cite this test method.9.2.2 Made-To-Fit SpecimenSmall-size samples made tofit the exterior bounds of the guarded hot pl
46、ate or slightly largercan be used to provide comparative test results. Measurementresults from such samples should be comparable, but notidentical, to full-size samples of the same construction, Resultsfrom made-to-fit specimens cannot be used for consumer-facing claims that cite this test method.9.
47、3 Specimen Pre-Inflating and Conditioning:9.3.1 For Inflatable Mattresses, fill the specimen to 3.7 kPa(0.2 kPa above the standard fill pressure to facilitate the fillpressure equalization) with a suitable pump (for example, a raftpump) in the test environmental conditions. Compressed air ormouth bl
48、owing are not recommended to avoid introducingmoisture, particulates, and oils which are commonly found incompressed air systems.NOTE 1To promote even distribution of insulation, test specimenswith loose filling shall be inflated and conditioned in the orientation inwhich they are to be tested.9.3.2
49、 Condition specimens in test environmental conditions.9.3.2.1 Minimum 4 h for inflating mattresses after 9.3.1.9.3.2.2 Minimum 2 h for non-inflatable mattresses.9.4 Measurement Locations in a Specimen:9.4.1 Rectangular MattressesMark three locational mea-surement lines equally spaced at 0.25 L, 0.5 L (centrallocation), and 0.75 L, where L is the length of the mattress, seeFig. 2. If the specimen is shorter than double the length of theguarded hot plate, then the specimen shall be measured withthe edge of the guarded hot plate aligned to the
