1、Designation: C 1153 97 (Reapproved 2003)e1Standard Practice forLocation of Wet Insulation in Roofing Systems UsingInfrared Imaging1This standard is issued under the fixed designation C 1153; the number immediately following the designation indicates the year oforiginal adoption or, in the case of re
2、vision, 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.e1NOTEWarning notes were editorially moved into the standard text in April 2003.1. Scope1.1 This practice app
3、lies to techniques that employ infraredimaging at night to determine the location of wet insulation inroofing systems that have insulation above the deck in contactwith the waterproofing. This practice includes ground-basedand aerial inspections. (WarningCaution should be taken inhandling any cryoge
4、nic liquids and pressurized gases requiredfor use in this practice.) (WarningExtreme caution shouldbe taken when accessing or walking on roof surfaces and whenoperating aircraft at low altitudes, especially at night.)(WarningIt is a good safety practice for at least two peopleto be present on the ro
5、of surface at all times when ground-based inspections are being conducted.)1.2 This practice addresses criteria for infrared equipmentsuch as minimum resolvable temperature difference, spectralrange, instantaneous field of view, and field of view.1.3 This practice addresses meteorological conditions
6、 underwhich infrared inspections should be performed.1.4 This practice addresses the effect of roof construction,material differences, and roof conditions on infrared inspec-tions.1.5 This practice addresses operating procedures, operatorqualifications, and operating practices.1.6 This practice also
7、 addresses verification of infrared datausing invasive test methods.1.7 The values stated in SI units are to be regarded asstandard.1.8 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 establ
8、ish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. Specific precau-tionary statements are given in 1.1.2. Referenced Documents2.1 ASTM Standards:C 168 Terminology Relating to Thermal Insulation2D 1079 Terminology Relating to Roofing,
9、 Waterproofing,and Bituminous Materials3E 1149 Definitions of Terms Relating to NDT by InfraredThermography4E 1213 Test Method for Minimum Resolvable TemperatureDifference for Thermal Imaging Systems52.2 ANSI-ASHRAE Standard:ANSI-ASHRAE Standard 101Application of InfraredSensing Devices to the Asses
10、sment of Building Heat LossCharacteristics62.3 ISO Standard:ISO/DP 6781.3EThermal InsulationQualitative Detec-tion of Thermal Irregularities in Building EnvelopesInfrared Method63. Terminology3.1 Definitions:3.1.1 blackbody, nthe ideal, perfect emitter and absorberof thermal radiation. It emits radi
11、ant energy at each wavelengthat the maximum rate possible as a consequence of its tempera-ture, and absorbs all incident radiance. (See TerminologyC 168.)3.1.2 core, na small sample encompassing at least 13 cm2of the roof surface area taken by cutting through the roofmembrane and insulation and remo
12、ving the insulation todetermine its composition, condition, and moisture content.3.1.3 detection, nthe condition at which there is a consis-tent indication that a thermal difference is present on thesurface of the roof. Detection of thermal anomalies can be1This practice is under the jurisdiction of
13、 ASTM Committee C16 on ThermalInsulation and is the direct responsibility of Subcommittee C16.30 on ThermalMeasurement.Current edition approved April 10, 2003. Published April 2003. Originallyapproved in 1990. Last previous edition approved in 1997 as C 1153 97.2Annual Book of ASTM Standards, Vol 04
14、.06.3Annual Book of ASTM Standards, Vol 04.04.4Discontinued. Replaced by E 1316. See 1990 Annual Book of ASTM Standards,Vol 03.03.5Annual Book of ASTM Standards, Vol 03.03.6Available from American National Standards Institute, 25 W. 43rd St., 4thFloor, New York, NY 10036.1Copyright ASTM Internationa
15、l, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.accomplished when they are large enough and close enough tobe within the spatial resolution capabilities of the imagingsystem; that is, when their width is at least two times theproduct of the instantaneous field
16、of view (IFOV) (see 3.1.10)of the system and the distance from the system to the surfaceof the roof divided by 1000.3.1.4 emittance, e, nthe ratio of the radiant flux emitted bya specimen to that emitted by a blackbody at the sametemperature and under the same conditions. (See TerminologyC 168.)3.1.
17、5 expansion joint, na structural separation or flexibleconnection between two building elements that allows freemovement between the elements without damage to the roofingor waterproofing system. (See Terminology D 1079.)3.1.6 field-of-view, (FOV), nthe total angular dimensions,expressed in radians,
18、 within which objects can be imaged,displayed and recorded by a stationary imaging device.3.1.7 infrared imaging line scanner, nan apparatus thatscans along a single line for variations in infrared radiance andis moved perpendicular to that line to produce a two-dimensional image of the region scann
19、ed.3.1.8 infrared imaging system, nan apparatus that con-verts the spatial variations in infrared radiance from a surfaceinto a two-dimensional image, in which variations in radianceare displayed as a range of colors or tones.3.1.9 infrared thermography, nthe process of generatingimages that represe
20、nt variations in infrared radiance of surfacesof objects.3.1.10 instantaneous field of view, (IFOV), nthe smallestangle, in milliradians, that can be instantaneously resolved bya particular infrared imaging system.3.1.11 line scanner, nan apparatus that scans along asingle line of a scene to provide
21、 a one-dimensional thermalprofile of the scene. (See Terminology E 1149.)3.1.12 membrane, na flexible or semiflexible roof cover-ing or waterproofing whose primary function is the exclusionof water. (See Terminology D 1079.)3.1.13 minimum resolvable temperature difference (MRTD),na measure of the ab
22、ility of operators of an infrared imagingsystem to discern temperature differences with that system. TheMRTD is the minimum temperature difference between a fourslot test pattern of defined shape and size and its blackbodybackground at which an average observer can discern thepattern with that infra
23、red imaging system at a defined distance.3.1.14 moisture meter probe, nan invasive (electricalresistance or galvanometric type) test that entails the insertionof a meter probe(s) through the roof membrane to indicate thepresence of moisture within the roofing system.3.1.15 radiance, nthe rate of rad
24、iant emission per unitsolid angle and per unit projected area of a source in a statedangular direction from the surface (usually the normal). (SeeTerminology C 168.)3.1.16 recognition, nthe ability to differentiate betweendifferent types of thermal patterns such as board-stock, picture-framed and am
25、orphous. Recognition of thermal anomalies canbe accomplished when their width is at least eight times theproduct of the IFOV of the infrared imaging system and thedistance from the system to the surface of the roof divided by1000.3.1.17 roof section, na portion of a roof that is separatedfrom adjace
26、nt portions by walls or expansion joints and inwhich there are no major changes in the components.3.1.18 roofing system, nan assembly of interacting com-ponents designed to weatherproof, and normally to insulate, abuildings top surface. (See Terminology D 1079.)3.1.19 survey window, nthe time period
27、 during whichroof moisture surveys can be successfully conducted accordingto the requirements of Section 10.3.1.20 thermal anomaly, na thermal pattern of a surfacethat varies from a uniform color or tone when viewed with aninfrared imaging system. Thermal anomalies may be caused bywet insulation.3.1
28、.21 thermogram, na recorded visual image that mapsthe apparent temperature pattern of an object or scene into acorresponding contrast or color pattern. (See TerminologyE 1149 with the word “recorded” added.)4. Significance and Use4.1 This practice should be used to outline the minimumnecessary eleme
29、nts and conditions to obtain an accuratedetermination of the location of wet insulation in roofingsystems using infrared imaging.4.2 This practice is not meant to be an instructional docu-ment or to provide all the knowledge and background neces-sary to provide an accurate analysis. For further info
30、rmation,see ANSI-ASHRAE Standard 101 and ISO/DP 6781.3E.4.3 This practice does not provide methods to determine thecause of moisture or its point of entry. It does not address thesuitability of any particular system to function capably aswaterproofing.5. Infrared Survey Techniques5.1 Ground-Based:5.
31、1.1 Walk-OverWalking on a roof using an infraredimaging system. The system may be hand-carried or mountedon a cart. Thermograms are taken of areas of interest. Areasthat appear to contain wet insulation are identified and markedfor verification.5.1.2 Elevated Vantage PointUse of an infrared imagings
32、ystem from an elevated vantage point may provide animproved view of the roof.5.2 Aerial:5.2.1 Real-Time ImagingUse of an infrared imaging sys-tem from an aircraft. Thermograms are obtained for the entireroof.5.2.2 Line Scanner ImagingUse of a line scanner from anaircraft to record thermal imagery fo
33、r the entire roof.6. Instrument Requirements6.1 General:6.1.1 ObjectiveInstrument requirements have been estab-lished in order to permit location of insulation that has lost aslittle as 20 % of its insulating ability because it containsmoisture.C 1153 97 (2003)e126.1.2 Spectral RangeThe infrared ima
34、ging system shalloperate within a spectral range from 2 to 14 m. A spotradiometer or nonimaging line scanner is not sufficient.6.1.3 Minimum Resolvable Temperature Difference(MRTD)The MRTD at 20C shall be 0.3C.6.1.3.1 The survey shall be conducted with the thermalimaging system only on sensitivity s
35、ettings that meet thisrequirement.6.1.4 Test for Minimum Resolvable Temperature Difference:6.1.4.1 Instrument SettingThe thermal imaging systemshall be tested at each sensitivity that the system will be used.6.1.4.2 Test Target PatternThe test target shall consist oftwo plates with known temperature
36、s, located in front of theimaging system. The near plate shall have four equally spacedslots each having 7:1 height-to-width ratio (see Fig. 1).6.1.4.3 Test GeometryRefer to Fig. 1. The ratio of thewidth, (w), on the test pattern to the distance, (d), to theimaging system shall be established, using
37、 the maximum IFOVallowed for the type of survey being conducted, as follows:w/d , 0.002 IFOV!where:w and d are in the same units and IFOV is in milliradians.Maximum allowable values of IFOV are defined in 6.2.2, 6.3.2,and 6.4.2.6.1.4.4 Test ProcedureIn accordance with Test MethodE 1213, the temperat
38、ure difference between the two plates ofthe target is slowly increased without communicating with theobserver. The observer announces when the test pattern comesinto view on the display. The temperature at this point isrecorded.6.1.4.5 Test ReplicatesBecause of differences in visualacuity, more than
39、 one observer shall perform the procedure in6.1.4.4. The average temperature difference is the MRTD forthat test condition.6.2 Walk-Over Surveys:6.2.1 Anomaly SizeInstrument requirements have beenestablished to permit recognition of areas of wet insulation assmall as 0.15 m on a side.6.2.2 Recogniti
40、on Distance, FOV and IFOVRecognitioncan be accomplished when the width of a thermal anomaly, inmetres, is at least 0.008 times the product of the IFOV of thesystem and the distance, in metres, from the system to theanomaly. Since the walkover survey shall be accomplished at amaximum distance of 5 m,
41、 the IFOV of the apparatus shall be3.8 milliradians, or less. The horizontal and vertical FOVs shallbe at least 0.21 rad (12) by 0.10 rad (6), respectively.6.3 Elevated Vantage Point Surveys:6.3.1 Anomaly SizeInstrument requirements have beenestablished to permit recognition of areas of wet insulati
42、on assmall as 0.15 m on a side.6.3.2 Recognition Distance, FOV and IFOVSince recog-nition must be possible at distances greater than 5 m, themaximum allowable IFOV in milliradians is related to dis-tance, (d), in metres from the infrared imaging system to theplace on the roof being scanned as follow
43、s:IFOV 5 18.8/dThe minimum horizontal FOV shall be 1.0/d and theminimum vertical FOV shall be 0.5/d, both expressed in rad.6.4 Aerial Surveys:6.4.1 Anomaly SizeAerial surveys shall be conductedwith infrared imaging line scanners or infrared imaging sys-tems that have the ability to detect areas of w
44、et insulation assmall as 0.3 m on a side directly below the system.6.4.2 Detection Distance, FOV and IFOVDetection canbe accomplished when the width of a thermal anomaly, inmetres, is at least 0.002 times the product of the IFOV of thesystem and the distance, in metres, from the system to theanomaly
45、. The maximum allowable IFOV is related to thevertical distance (d), in metres, above the roof, as follows:IFOV 5 150/dThe FOV along the line of flight and across the line of flightshall be at least 0.05 rad by 0.10 rad, respectively. The usablefield of view shall be within 0.35 rad of a point direc
46、tly belowthe infrared imaging system.7. Level of Knowledge7.1 The proper conduct of a roof moisture survey using aninfrared imaging system requires knowledge of how and underwhat circumstances the system can be used and a generalunderstanding of roof construction.7.2 Proper interpretation of infrare
47、d data requires knowl-edge of infrared theory, moisture migration, heat transfer,environmental effects, and roof construction as they apply toroof moisture analysis.8. Limitations (Applicability of Constructions)8.1 Applicable constructions include membrane systemscontaining any of the commercially
48、available rigid insulationboards. This includes boards made of organic fibers, perlite,cork, fibrous glass, cellular glass, polystyrene, polyurethane,isocyanurate, and phenolic. Composite boards and taperedsystems made from these materials can also be inspected as canroofs insulated with foamed-in-p
49、lace polyurethane.8.2 When extruded polystyrene insulation is placed underballast and above a protected membrane, it is quite difficult tolocate moisture in the insulation below the membrane by use ofinfrared thermography.FIG. 1 Test Arrangement for Minimum Resolvable TemperatureDifference (MRTD) of an Infrared Imaging SystemC 1153 97 (2003)e138.3 Wet applied insulations such as lightweight concrete andwet applied decks such as gypsum can be difficult to surveysince they may retain significant quantities of constructionwater.8.4 W
