1、Designation: C 653 97 (Reapproved 2007)Standard Guide forDetermination of the Thermal Resistance of Low-DensityBlanket-Type Mineral Fiber Insulation1This standard is issued under the fixed designation C 653; the number immediately following the designation indicates the year oforiginal adoption or,
2、in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This guide describes the calculation and interpolation ofa thermal resistance va
3、lue for low-density blanket-type insula-tion material at a particular density and thickness having beenselected as representative of the product. It requires measuredvalues of this average density and thickness, as well asapparent thermal conductivity values determined by either TestMethod C 177, C
4、518, or C 1114.1.2 This guide applies to a density range for mineral-fibermaterial of roughly 6.4 to 48 kg/m3(0.4 to 3.0 lb/ft3). It isprimarily intended to apply to low-density, mineral-fiber massinsulation batts and blankets, exclusive of any membranefacings. Apparent thermal conductivity data for
5、 these productsare commonly reported at a mean temperature of 23.9C (75F)and a hot-to-cold plate temperature difference of 27.8C (50F)or 22.2C (40F).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 s
6、tandard 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:2C 167 Test Methods for Thickness and Density of Blanketor Batt Thermal InsulationsC 168 Terminology Relating to Thermal Ins
7、ulationC 177 Test Method for Steady-State Heat Flux Measure-ments and Thermal Transmission Properties by Means ofthe Guarded-Hot-Plate ApparatusC 518 Test Method for Steady-State Thermal TransmissionProperties by Means of the Heat Flow Meter ApparatusC 1045 Practice for Calculating Thermal Transmiss
8、ionProperties Under Steady-State ConditionsC 1114 Test Method for Steady-State Thermal TransmissionProperties by Means of the Thin-Heater Apparatus3. Terminology3.1 DefinitionsFor definitions used in this guide, refer toTerminology C 168.3.2 Definitions of Terms Specific to This Standard:3.2.1 appar
9、ent thermal conductivity, lthe ratio of thespecimen thickness to thermal resistance of the specimen. It iscalculated as follows:l5L/R W/mk! or Btu in./ft2hF! (1)3.2.1.1 DiscussionFor this type of material an expressionfor the apparent thermal conductivity as a function of densityis:l5a 1 bD 1 c/D (2
10、)where a, b, c = parameters characteristic of a product, and related tothe conductivity of the gas, the conductivity of the solid and theconductivity due to radiation.(1)33.3 Symbols:R = thermal resistance, (m2K/W) or (hft2F/Btu)l = apparent thermal conductivity, (W/mK) or (Btuin/hft2F)Q/A = heat fl
11、ow per unit area, (W/m2) or (Btu/hft2)D = bulk density of a specimen, (kg/m3) or (lb/ft3)L = measured specimen thickness, (m) or (in.)T = apparatus plate temperature, (K) or (F)L8 = specimen thickness if the sample from which thespecimen is selected does not recover to labelthickness, (m) or (in.)s
12、= estimate of the standard deviation for a set of datapointsD = apparatus systematic errorC = overall uncertainty in a measured R-value3.3.1 Subscripts:1This guide is under the jurisdiction of ASTM Committee C16 on ThermalInsulation and is the direct responsibility of Subcommittee C16.30 on ThermalM
13、easurement.Current edition approved March 1, 2007. Published April 2007. Originallyapproved in 1970. Last previous edition approved in 2002 as C 653 97(2002).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of A
14、STMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3The boldface numbers in parentheses refer to a list of references at the end ofthis standard.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United S
15、tates.av= signifies average of a lotH= refers to hot surfaceC= refers to cold surfaceT= refers to test specimenN= refers to nominal property for the product, as shownon the product labeli= refers to a set of data pointss= refers to a particular specimen4. Significance and Use4.1 This guide provides
16、a method to determine the thermalperformance of low-density blanket-type insulation. It may beused for the purposes of quality assurance, certification, orresearch.4.2 The thermal resistance of low-density insulation de-pends significantly on the density, the thickness, and thermalconductivity. Typi
17、cal low-density, mineral-fiber insulation forbuildings may vary in density from one specimen to the next.4.3 Thermal tests are time-consuming in comparison withdensity and thickness measurements. Low-density insulationmaterial is produced in large quantities. A typical lot would bea truckload or the
18、 amount necessary to insulate a house.4.4 The relatively low unit cost of this product and therelatively high cost of thermal resistance testing makes itcost-effective to test only a small percentage of the productarea. It is recommended that there be a determination of thedensity that is representa
19、tive of a lot by the measurement of theaverage density of a statistically representative sampling.4.5 Afewer number of thermal measurements are then madeto determine the apparent thermal conductivity at the previ-ously determined representative density. The essential signifi-cance of this guide is t
20、hat a large lot of variable material is bestcharacterized by: (a) determining the representative density,and by (b) determining the thermal property at this represen-tative density with a small number of thermal measurements.4.6 Building insulation products are commonly manufac-tured in thicknesses
21、ranging from 19 to 330 mm (0.75 to 13 in.)inclusive. Experimental work has verified that there is adependence of lappon thickness for some low density materi-als.4.7 The upper limit of test thickness for specimens evalu-ated using Test Methods C 177, C 518, and C 1114 is estab-lished based upon the
22、apparatus design, overall dimensions,expected thermal resistivity level and desired target accuracy.The testing organization is responsible for applying theserestrictions when evaluating a product to ensure that the resultsmeet applicable product labels and any existing regulatoryrequirements.(2)4.8
23、 Extrapolation of the apparent thermal conductivity orthe thermal resistance beyond the ranges of thickness ordensity of products tested is not valid.5. Sampling5.1 For low-density mineral-fiber insulation, a lot samplesize of 75 to 150 ft2is recommended to determine the averagedensity, Dav. Density
24、 is determined by using Test MethodC 167; take care to avoid the use of damaged material.5.2 In order to account for the variation in l-value due toproduct density variability, measure a minimum of three “lversus D” data points on three different samples. This repre-sents nine data points for the “l
25、 versus D” curve.Again, this “lversus D” curve is developed to determine the l-value at aparticular representative density characteristic of a lot ofmaterial.5.3 The size of a lot of material to be characterized, theamount of material measured for the representative values ofdensity and thickness, a
26、nd the frequency of tests all depend onthe users needs, which could be related to quality assurance bya manufacturer, certification, or research.6. Procedure6.1 This procedure uses nine li; Di data points allmeasured at the same hot and cold plate temperatures, toestablish an interpolation equation
27、for the determination of thel-value at the average density, Dav. That is, the subscript irefers to the ithtest point. The Diis the average density of thespecimen within the apparatus meter-area. The thermal resis-tance at Lavand Davis as follows:Rav5 Lav/lav(3)6.2 Before the set of “apparent thermal
28、 conductivity versustest density (liversus Di)” data points can be measured on anapparatus, it is necessary to choose the test densities andthicknesses. Three procedures for this choice are described inAnnex A1.6.2.1 Procedure AAsingle test specimen is compressed toobtain different densities (A1.2).
29、 This procedure offers theadvantage of less test time to obtain three test points.6.2.2 Procedure BA different specimen is used for eachtest point (A1.3). This method has the advantage of a betterstatistical sampling with regard to material variability.6.2.3 Procedure CTest at Davthereby eliminating
30、 theneed for an interpolation (A1.4).6.3 Obtain a test value for l at each of the three densities.These three sets of test values result in three equations of theform of Eq 2 in 3.2.2. These are solved simultaneously todetermine the values of as, bs, and cscorresponding tospecimen s (see A2.1.2).NOT
31、E 1Small errors in the measured values of l will result in largevariations in the values of a, b, and c. Even so, the uncertainty of theinterpolated value of l will be comparable to the measured error in l.6.4 Whenever possible, calculate running averages for thespecific product lot based on a numbe
32、r N equal to 20 or moresets of product curve parameters (as;bs;cs). Remember from6.3 that each of these sets requires three test points (seeA2.1.3).6.4.1 A larger number N results in more consistent valuesfor a, b, and c; a smaller N represents a more current data base.6.5 In 6.3 a set of parameter
33、values was calculated, and in6.4 a running average was calculated. This section describeshow to obtain an interpolation curve (or equivalently a set ofinterpolation curve parameters) for the next sample, s, when ithas been possible to previously obtain a running average set, (a; b; c). The given val
34、ues are the set a; b; c and themeasured values of liat three densities, Di.NOTE 2Parameter c is expected to account for most of the variation inC 653 97 (2007)2the “l versus D” curve from specimen to specimen. When the density isless than 16 kg/m3(1 lb/ft3), c is the dominant parameter causing theva
35、riance of l from specimen to specimen. Then the previously determinedvalues, a, and b are used, along with a measurement of l at a particulardensity, to calculate a value of c for a particular specimen, s. In order tohave a better estimate of the mean, the value of c is thusly determined forthree va
36、lues of density resulting in the value cs. The interpolation to the lvalue at the average density, Dav, is calculated as follows, using Eq 3.ls5 a 1 bDav1 cs/Dav(4)An example of this calculation is in A2.1.46.6 Compute the average value of lavbased on as manyvalues of lsthat have been determined. Re
37、member from 6.3and 6.5 that three test points are required to obtain a value forlav. Common practice is to base an average lavon three valuesof ls.6.7 Calculate the R-value, Rav, of the product at the averagedensity and thickness (see Section 5 and A1.1) as follows:Rav5 LT/lav(5)7. Report7.1 The rep
38、ort shall contain the following information:7.1.1 The values of the average thermal resistance, densityand thickness, the sample size, and the supporting data.7.1.2 The test methods used and the information on thevalues and uncertainties of apparent thermal conductivity anddensity that is required i
39、n Test Method C 167, C 177, C 518, orC 1114.7.1.3 The procedure used to obtain the l versus D curvealong with the equation for the curve itself.8. Precision and Bias8.1 There are a number of ways to combine the systematicand random uncertainties that contribute to an overall uncer-tainty of a measur
40、ed quantity. The following procedure isintended as a guideline.8.2 The term precision is used in this guide in the sense ofrepeatability. The estimation of the standard deviation, s, for aset of measurements with a normal distribution is the plus andminus range about an average value or curve, withi
41、n which68 % of the observations lie. The s is used to quantify theprecision.8.3 The term bias as used in this guide represents the totaluncertainty in a set of measurements, including apparatussystematic error, apparatus precision, and the material variabil-ity.8.4 The apparatus precision is the var
42、iation that occurswhen repeated observations are made on a single specimen oridentical specimens. It is quantified by sa, and it is required asinput data from either Test Method C 177, C 518,orC 1114.(3)8.5 The material variability is partly taken into account bythe l versus D curve.When different s
43、pecimens are tested therewill be an amount of variation about the average l versus Dcurve in addition to the apparatus precision. This additionalvariation is here called the material variability and is desig-nated by sm.8.6 The total “repeatability” uncertainty on a l versus Dgraph will be the sum o
44、f the aforementioned uncertainties andis designated by sl.sl5 sa21 sm2!0.5(6)8.7 In order to know what slis, it is necessary to plot anumber of l versus D test points. Twenty or more points arerecommended. It is then possible to determine by a graphical ora mathematical method (see Annex A3) what is
45、 the 1s bandwithin which 68 % of the points lie or what is the 2s bandwithin which 95 % of the points lie.8.8 When more than one apparatus is used to develop the lversus D curve, there will be a difference between the averagevalues on the same set of specimens due to a systematicdifference among the
46、 apparatus.8.9 The measured data from an apparatus have associatedwith it an estimate of the possible systematic error in l of thatapparatus. It is designated by Dland is provided as input fromTest Method C 177, C 518, or C 1114.8.10 For the purposes of this guide the overall accuracy, Cl,of the rep
47、orted l-value is the sum of the overall repeatability(1s for a 68 % confidence band) and the apparatus systematicerror.Cl5 sl1Dl(7)8.11 The percent “precision and bias” uncertainties in thereported R-value is calculated as follows, based on Eq 1:Rav5 LT/lav(8)8.11.1 The estimate of the residual stan
48、dard deviation of Lavand lavis made by statistical methods (see Annex A3). Thepercent residual standard deviation in the reported R-value isthen:sRRav5SsL2LT21sl2lr2 D0.5(9)8.11.2 In order to calculate the percent bias uncertainty inRv, it is necessary to obtain from Test Method C 167 theestimate of
49、 systematic uncertainty in the measurement of Lav.This is of the order of the resolution of the measurementdevice, and it is designated here by DL. For the purpose of thisguide, the overall percent bias in the reported R-value iscalculated as follows:CRRav5SsL1DL!2Lav21sl1Dl!2lav2 D0.5(10)9. Keywords9.1 blanket; low-density; mineral fiber; thermal resistanceC 653 97 (2007)3ANNEXES(Mandatory Information)A1. PROCEDURES TO DETERMINE THE TEST VALUES FOR DENSITY AND THICKNESSA1.1 General ConsiderationsA1.1.1 With reference to 5.2, the samp
