1、Designation:C55015Standard Test Method forMeasuring Trueness and Squareness of Rigid Block andBoard Thermal Insulation1This standard is issued under the fixed designation C550;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year
2、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 This test method covers locations f
3、or measuring thetrueness and squareness of rigid block/board thermal insula-tion.This test method does not purport to address the variabil-ity in board thickness.Thickness is addressed in other ASTMstandards.1.2 The values stated in inch-pound units are to be regardedas standard.The values given in
4、parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.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 standard to establish appro-pri
5、ate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2C168 Terminology Relating to Thermal InsulationC390 Practice for Sampling and Acceptance of ThermalInsulation LotsE177 Practice for Use of the Terms Preci
6、sion and Bias inASTM Test Methods3.Terminology3.1 DefinitionsFor definitions of terms used in this testmethod,refer to Terminology C168.3.2 Definitions of Terms Specific to This Standard:3.2.1 squarenessthe lack of deviation from a right angle.3.2.2 truenessthe lack of deviation from straightness or
7、flatness.4.Significance and Use4.1 It is possible that insulating blocks or boards that are nottrue or square will not fit properly.It is possible that extra laborwill be required to obtain proper fit and that this could affectthe product performance as well as the appearance of thefinished installa
8、tion.4.2 This test method provides terminology and describeslocations for obtaining consistent measurements of truenessand squareness of blocks and boards.5.Apparatus5.1 Straightedge,minimum length equal to the maximumdimension of the block or board with a maximum out oftrueness of 6 0.003 in./ft(60
9、.25 mm/m).5.2 Rigid Ruler,graduated to 0.03 in.(1.0 mm)or finer.5.3 Square,shall have sides at least as long as the longestside of the block.If the longest side of the block is greater than20 in.(500 mm),then the length of the square must be at least20 in.(500 mm).The maximum deviation from 90 shall
10、 be nomore than 63 min(60.9 mrad).5.4 Flat Surface,large enough to accommodate the block orboard in its full length and width dimensions,with a truenessof 60.008 in./ft(60.65 mm/m).5.5 Feeler Gage Set,from 0.001 to 0.020 in.(0.03 to 0.50mm).5.6 Tape Measure,steel,long enough to measure the longestsi
11、de of the block,graduated in 0.031 in.(1 mm)intervals.6.Test Specimens6.1 The test specimens shall be of commercial size.6.2 The number of test specimens shall be defined by theappropriate product specification.6.3 When the appropriate product specification does notcover sampling,samples shall be se
12、lected in accordance withPractice C390 inspection requirements.7.Procedure7.1 Edge Trueness in the x/y Direction:1This test method is under the jurisdiction ofASTM Committee C16 on ThermalInsulation and is the direct responsibility of Subcommittee C16.32 on MechanicalProperties.Current edition appro
13、ved Oct.15,2015.Published December 2015.Originallyapproved in 1964.Last previous edition approved in 2010 as C550 10.DOI:10.1520/C0550-15.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume info
14、rmation,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 7.1.1 With the straightedge next to the block/board on theflat surface,concave deviation from true shall be determined
15、 atthe point of maximum deviation(see Fig.1 A and B).7.1.2 For convex deviation from true,the deviation shall bemeasured by equalizing the distance between the straightedgeand the block/board at both corners of the block/board(see Fig.1 A and B).7.1.3 Deviation from true shall be determined to the n
16、earest0.03 in.(1.0 mm).7.2 Edge Trueness in the z(Thickness)Direction:7.2.1 With the square next to the block/board as shown inFig.1C,the concave deviation from true shall be determined atthe point of maximum deviation.7.2.2 For convex deviation from true,the deviation shall bemeasured by equalizing the distance between the square andthe block/board at both surfaces of the block/board as shown inFig.1D.7.2.3 Deviation from true shall be determined to the nearest0.03 in.(0.8 mm).7.3 Edge Squarene
