1、Designation: C653 97 (Reapproved 2012)C653 17Standard Guide forDetermination of the Thermal Resistance of Low-DensityBlanket-Type Mineral Fiber Insulation1This standard is issued under the fixed designation C653; the number immediately following the designation indicates the year oforiginal adoption
2、 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 guide describes the calculation and interpolation of a thermal resistan
3、ce value for low-density blanket-type insulationmaterial at a particular density and thickness having been selected as representative of the product. It requires measured values ofthis average density and thickness, as well as apparent thermal conductivity values determined by either Test Method C17
4、7, C518,or C1114.1.2 This guide applies to a density range for mineral-fiber material of roughly 6.4 to 48 kg/m3 (0.4 to 3.0 lb/ft3). It is primarilyintended to apply to low-density, mineral-fiber mass insulation batts and blankets, exclusive of any membrane facings. Apparentthermal conductivity dat
5、a for these products are commonly reported at a mean temperature of 23.9C (75F) and a hot-to-cold platetemperature difference of 27.8C (50F) or 22.2C (40F).1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user o
6、f this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C167 Test Methods for Thickness and Density of Blanket or Batt Thermal InsulationsC168 Terminology Relating to Thermal
7、 InsulationC177 Test Method for Steady-State Heat Flux Measurements and Thermal Transmission Properties by Means of theGuarded-Hot-Plate ApparatusC518 Test Method for Steady-State Thermal Transmission Properties by Means of the Heat Flow Meter ApparatusC687 Practice for Determination of Thermal Resi
8、stance of Loose-Fill Building InsulationC1045 Practice for Calculating Thermal Transmission Properties Under Steady-State ConditionsC1114 Test Method for Steady-State Thermal Transmission Properties by Means of the Thin-Heater Apparatus3. Terminology3.1 DefinitionsFor definitions used in this guide,
9、 refer to Terminology C168.3.2 Definitions of Terms Specific to This Standard:3.2.1 apparent thermal conductivity, the ratio of the specimen thickness to thermal resistance of the specimen. It is calculatedas follows:5L/R W/mk!or Btuin./ft 2hF! (1)3.2.1.1 DiscussionFor this type of material an expre
10、ssion for the apparent thermal conductivity as a function of density is:1 This guide is under the jurisdiction of ASTM Committee C16 on Thermal Insulation and is the direct responsibility of Subcommittee C16.30 on Thermal Measurement.Current edition approved March 1, 2012March 1, 2017. Published Aug
11、ust 2012March 2017. Originally approved in 1970. Last previous edition approved in 20072012as C653 97 (2012).(2007). DOI: 10.1520/C0653-97R12.10.1520/C0653-17.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of A
12、STM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically
13、possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700
14、, West Conshohocken, PA 19428-2959. United States15a1bD1c/D (2)where a, b, c = parameters characteristic of a product, and related to the conductivity of the gas, the conductivity of thesolid and the conductivity due to radiation.radiation (1).33.3 Symbols:R = thermal resistance, (m2 K/W) or (hft2 F
15、/Btu) = apparent thermal conductivity, (W/mK) or (Btuin/hft2F)Q/A = heat flow 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)L = specimen thickness if the sample from which
16、the specimen is selected does not recover to label thickness, (m) or (in.)s = estimate of the standard deviation for a set of data points = apparatus systematic error = overall uncertainty in a measured R-value3.3.1 Subscripts:av = signifies average of a lotH = refers to hot surfaceC = refers to col
17、d surfaceT = refers to test specimenN = refers to nominal property for the product, as shown on the product labeli = refers to a set of data pointss = refers to a particular specimen4. Significance and Use4.1 This guide provides a method to determine the thermal performance of low-density blanket-ty
18、pe insulation. It may be usedfor the purposes of quality assurance, certification, or research.4.2 The thermal resistance of low-density insulation depends significantly on the density, the thickness, and thermalconductivity. Typical low-density, mineral-fiber insulation for buildings may vary in de
19、nsity from one specimen to the next.4.3 Thermal tests are time-consuming in comparison with density and thickness measurements. Low-density insulation materialis produced in large quantities. A typical lot would be a truckload or the amount necessary to insulate a house.4.4 The relatively low unit c
20、ost of this product and the relatively high cost of thermal resistance testing makes it cost-effectiveto test only a small percentage of the product area. It is recommended that there be a determination of the density that isrepresentative of a lot by the measurement of the average density of a stat
21、istically representative sampling.4.5 A fewer number of thermal measurements are then made to determine the apparent thermal conductivity at the previouslydetermined representative density.The essential significance of this guide is that a large lot of variable material is best characterizedby: (a)
22、determining the representative density, and by (b) determining the thermal property at this representative density with asmall number of thermal measurements.4.6 Building insulation products are commonly manufactured in thicknesses ranging from 19 to 330 mm (0.75 to 13 in.)inclusive. Experimental wo
23、rk has verified that there is a dependence of app on thickness for some low density materials.4.7 The upper limit of test thickness for specimens evaluated using Test Methods C177, C518, and C1114 is established basedupon the apparatus design, overall dimensions, expected thermal resistivity level a
24、nd desired target accuracy. The testingorganization is responsible for applying these restrictions when evaluating a product to ensure that the results meet applicableproduct labels and any existing regulatory requirements.requirements (2).4.8 Extrapolation of the apparent thermal conductivity or th
25、e thermal resistance beyond the ranges of thickness or density ofproducts tested is not valid.5. Sampling5.1 For low-density mineral-fiber insulation, a lot sample size of 75 to 150 ft2 is recommended to determine the average density,Dav. Density is determined by using Test Method C167; take care to
26、 avoid the use of damaged material.5.2 In order to account for the variation in -value due to product density variability, measure a minimum of three “ versusD” data points on three different samples. This represents nine data points for the “ versus D” curve. Again, this “ versus D”curve is develop
27、ed to determine the -value at a particular representative density characteristic of a lot of material.3 The boldface numbers in parentheses refer to a list of references at the end of this standard.C653 1725.3 The size of a lot of material to be characterized, the amount of material measured for the
28、 representative values of densityand thickness, and the frequency of tests all depend on the users needs, which could be related to quality assurance by amanufacturer, certification, or research.6. Procedure6.1 This procedure uses nine i; Di data points all measured at the same hot and cold plate te
29、mperatures, to establish aninterpolation equation for the determination of the -value at the average density, Dav. That is, the subscript i refers to the ith testpoint. The D iI is the average density of the specimen within the apparatus meter-area. The thermal resistance at Lav and Dav is asfollows
30、:Rav5Lav/av (3)6.2 Before the set of “apparent thermal conductivity versus test density (i versus Di)” data points can be measured on anapparatus, it is necessary to choose the test densities and thicknesses. Three procedures for this choice are described in Annex A1.6.2.1 Procedure AA single test s
31、pecimen is compressed to obtain different densities (A1.2). This procedure offers theadvantage of less test time to obtain three test points.6.2.2 Procedure BAdifferent specimen is used for each test point (A1.3). This method has the advantage of a better statisticalsampling with regard to material
32、variability.6.2.3 Procedure CTest at Dav thereby eliminating the need for an interpolation (A1.4).6.3 Obtain a test value for at each of the three densities. These three sets of test values result in three equations of the formof Eq 2 in 3.2.1. These are solved simultaneously to determine the values
33、 of as, bs, and cs corresponding to specimen s (see A2.1.2).NOTE 1Small errors in the measured values of will result in large variations in the values of a, b, and c. Even so, the uncertainty of the interpolatedvalue of will be comparable to the measured error in .6.4 Whenever possible, calculate ru
34、nning averages for the specific product lot based on a number N equal to 20 or more setsof product curve parameters (as; bs; cs). Remember from 6.3 that each of these sets requires three test points (see A2.1.3).6.4.1 A larger number N results in more consistent values for a, b, and c; a smaller N r
35、epresents a more current data base.6.5 In 6.3 a set of parameter values was calculated, and in 6.4 a running average was calculated. This section describes howto obtain an interpolation curve (or equivalently a set of interpolation curve parameters) for the next sample, s, when it has beenpossible t
36、o previously obtain a running average set, (a; b; c). The given values are the set a; b; c and the measured valuesof i at three densities, Di.NOTE 2Parameter c is expected to account for most of the variation in the “ versus D” curve from specimen to specimen. When the density is lessthan 16 kg/m3 (
37、1 lb/ft3), c is the dominant parameter causing the variance of from specimen to specimen. Then the previously determined values, a,and b are used, along with a measurement of at a particular density, to calculate a value of c for a particular specimen, s. In order to have a better estimateof the mea
38、n, the value of c is thusly determined for three values of density resulting in the value cs. The interpolation to the value at the average density,Dav, is calculated as follows, using Eq 3.s 5a1bDav1cs/Dav (4)s 5a1bDav1cs/Dav (4)An example of this calculation is in A2.1.46.6 Compute the average val
39、ue of a v based on as many values of s that have been determined. Remember from 6.3 and 6.5that three test points are required to obtain a value for av. Common practice is to base an average av on three values of s.6.7 Calculate the R-value, Rav, of the product at the average density and thickness (
40、see Section 5 and A1.1) as follows:Rav5LT/av (5)7. Report7.1 The report shall contain the following information:7.1.1 The values of the average thermal resistance, density and thickness, the sample size, and the supporting data.7.1.2 The test methods used and the information on the values and uncert
41、ainties of apparent thermal conductivity and densitythat is required in Test Method C167, C177, C518, or C1114.7.1.3 The procedure used to obtain the versus D curve along with the equation for the curve itself.8. Precision and Bias8.1 There are a number of ways to combine the systematic and random u
42、ncertainties that contribute to an overall uncertaintyof a measured quantity. The following procedure is intended as a guideline.8.2 The term precision is used in this guide in the sense of repeatability. The estimation of the standard deviation, s, for a setof measurements with a normal distributio
43、n is the plus and minus range about an average value or curve, within which 68 % ofthe observations lie. The s is used to quantify the precision.C653 1738.3 The term bias as used in this guide represents the total uncertainty in a set of measurements, including apparatus systematicerror, apparatus p
44、recision, and the material variability.8.4 The apparatus precision is the variation that occurs when repeated observations are made on a single specimen or identicalspecimens. It is quantified by sa, and it is required as input data from either Test Method C177, C518, or C1114. (3).8.5 The material
45、variability is partly taken into account by the versus D curve. When different specimens are tested there willbe an amount of variation about the average versus D curve in addition to the apparatus precision. This additional variation ishere called the material variability and is designated by sm.8.
46、6 The total “repeatability” uncertainty on a versus D graph will be the sum of the aforementioned uncertainties and isdesignated by s.s5sa21sm 2!0.5 (6)8.7 In order to know what s is, it is necessary to plot a number of versus D test points. Twenty or more points arerecommended. It is then possible
47、to determine by a graphical or a mathematical method (see AnnexA3) what is the 1s band withinwhich 68 % of the points lie or what is the 2s band within which 95 % of the points lie.8.8 When more than one apparatus is used to develop the versus D curve, there will be a difference between the average
48、valueson the same set of specimens due to a systematic difference among the apparatus.8.9 The measured data from an apparatus have associated with it an estimate of the possible systematic error in of thatapparatus. It is designated by and is provided as input from Test Method C177, C518, or C1114.8
49、.10 For the purposes of this guide the overall accuracy, , of the reported -value is the sum of the overall repeatability (1sfor a 68 % confidence band) and the apparatus systematic error.5s1 (7)8.11 The percent “precision and bias” uncertainties in the reported R-value is calculated as follows, based on Eq 1:Rav5LT/av (8)8.11.1 The estimate of the residual standard deviation of Lav and av is made by statistical methods (see AnnexA3). The percentresidual stand
