Investigations were conducted regarding the use of the ultrasonic pulse echo and the infrared thermography nondestructive evaluation (NDE) methods for detecting voids and delaminations in adhesive-bonded seams of single-ply roofing membranes. Previous studies had indicated that these defects could be detected using the two NDE methods. In the present study, voids incorporated in 1.2 m (48 in.) long seam test specimens were located by the pulse-echo method using a wheel transducer to scan along the length of the seam. These results indicated that the ultrasonic pulse echo method using a wheel transducer can be useful as a field technique for assisting in the quality assessment of seams. When using the infrared thermography method to evaluate the seam specimens, it was found that, unlike previous studies, only sections of some voids were detected and that other voids were not detected at all. It was suggested that collapse of the voids due to the applied pressure during seam formation might have provided insufficient surface temperature differential between the bonded areas of the seam and the void areas of the seams during transient heat flow. The results raised concerns that the infrared thermography method may not be practical for the general detection of voids of seams in service.

Various factors affecting infrared temperature measurements are discussed. Temperature calibration curves at surrounding temperatures between -20°C and 25°C are presented for two infrared imaging systems operating in the 2 to 5 μm and 8 to 14 μm wavelength regions. The calibration curves for the 2 to 5 μm system were found to be independent to surrounding temperatures, while the calibration curves for the 8 to 14 μm system were found to be strongly dependent to surrounding temperatures. Equations to account for changes in surrounding temperatures are presented. Laboratory measurements of emissivity using both systems at different surrounding temperatures (22°C, 4°C, and -11°C) are given for several typical building materials. The emissivity measurements are used in computing surface temperatures of the materials. Comparisons are made between predicted and measured surface temperatures.

The use of infrared thermographic building diagnostics, prior to final closing, is an effective method of quality control. Thermal envelope studies using infrared technology, made prior to contractual release, are a cost effective means of insuring the buyer and builder that the thermal envelope performs to the specifications of the construction contract. Building owners and builders can both benefit. Builders are able to close jobs and avoid costly call backs after occupancy. Building owners gain knowledge as to how the building envelope can be expected to perform in coming seasons. A majority of problems can be avoided during construction when infrared thermographic building diagnostics are introduced at the beginning of a project. Problems may be dealt with during construction, not afterwards. Contractors are alerted to how their job affects the performance of other trades and materials in the structure. To gain the most from infrared thermography during the construction phase, the contractors and thermographer must have an understanding of each other's function. On-site visits during construction can provide contractors with a basic background of thermal imaging and familiarize the thermographer with various construction techniques and materials used.

Uncontrolled air leakage in a building enclosure is the main component of space heating and cooling costs. In Atlantic Canada, Public Works Canada has combined thermography and pressure testing to identify design and construction problems in new construction and to identify specific areas of air leakage in existing housing stock. A study case shows how thermography and pressure testing has been utilized to locate and compare specific areas of air leakage in a residence before and after air sealing. The study provides both quantitative and qualitative evidence of how air sealing increases the air tightness in building enclosures.

Computer image processing techniques have been used in the past to transforni radiant energy information into images. These techniques have allowed the user to spatially improve the information and assemble an infrared energy map of their subject. With the addition of complex conversion algorithms, these radiant energy pictures have been converted into temperature maps. Often the user is interested in a performing an analysis that is a function of the temperature as opposed to temperature itself. With conventional image processing systems, the user must still rely on either experience or other processing algorithms to interpret the information that the thermogram is representing. This paper discusses recent software advances which allow the user to continue the transformation process from radiant energy to desired end result.

Since 1976, Public Works Canada (PWC) has been involved in the development of thermographic equipment and techniques for building diagnostic purposes. Within the last five years PWC has focused on regional implementation of these developments through hiring of PWC trained thermographers and distribution of PWC modified thermographic equipment. This paper deals with regional thermographic development implementations in the area of building diagnostics. The thermographic development program, organizational structure and implementation procedures may be pertinent to those responsible for maintenance and operation of large amounts of property spread out over large geographical areas.

The temperature of an electrical circuit problem is determined by the relationship between power input to and from the component. Power input is I R. Power output depends on three modes of heat transfer. This paper presents experimental data which define the temperature versus power relationship for two specific cases.

In Cambridge, Massachusetts, in 1985, Thermosense 9 held an evening workshop on the use of infrared in the electric utility environments. This workshop brought together vendors, consultants, and utility personnel. The end result was a lively debate on a wide range of topics.

Knowledge of real coolant fluid circulation through solar collectors is important to evaluate their performances and to describe reaction of some solars installations. Infrared thermography is a non destructive way, which can be used without modifying the studied material in operation. From a qualitative point of vue, it allows us to detect some systematic and ponctual defects into solar collectors and into some solar collector sets. Digital processing of thermal images allowed us to quantify some parameters like coolant fluid rate of flow and speed inside absorbers and to determine really irrigated surface, whence the notion of irrigation ratio. At the end of these researchs, on in situ running solar collector, one method is proposed permitting to link transparent cover surface temperature range with solar collector irrigation.

The advanced increase of production has a demand for more complex control tools. The design of new IR-Sensors, e.g. infrared line scanners or AGEMA THV 870, has now opened new fields in the infrared technology. Together with the increasing power of digital processing the online monitoring - and processing can be used to improve the quality of the products. One typical field is the hot strip mill where with the introduction of the new line scanner (AGEMA THP-5) it is now possible to check the entire strip's temperature not only at one point but accross the entire strip giving a more accurate information about the temperature distribution. This will strongly correlate with the quality of the product. The constant monitoring of the product can also increase productivity and reduce problems in quality inspection.

Things to consider when integrating infrared sensors into systems include mounting and protecting the sensors properly and interfacing them to the rest of the system. Some of the considerations to be discussed apply to any sensor, and some are unique to infrared sensors. Mounting considerations include protection from atmospheric contamination and high ambient temperatures. The field of view and the background must be controlled. There are various ways of connecting infrared radiometers to systems, including current loop, voltage output, and digital interfaces. The sensors might be connected to various components, including displays, data acquisition systems, and controllers. One of the considerations in interfacing these sensors is electrical noise. It is also necessary to avoid ground loops which may adversely affect accuracy. Signals must be properly scaled between components, and conversion resolution allowed for. Issues such as speed and accuracy must be considered from the point of view of not just the sensor, but also the overall system.

In 1985, AGEMA Infrared Systems introduced, into the American market, the Thermoprofile-5 infrared linescanner. Choices can be made on how to implement its use. They are based on the specifications of the Thermoprofile-5 and total system requirements. Infra-Red Scanning Services, Inc. has developed an integrated infrared linescanning system that is both versatile and functional. Although it is designed for universal industrial applications, it is readily customized for the most demanding situation.

As in all fields of NDT,continuous developments and improvements in equipment reveal new techniques of inspection. This is particulary true in the case of thermography with the introdution for civil use of scanning infra-red cameras or contact thermography systems with combines fast scanning speeds with good spatial and thermal resolution. In combination with suitable sources such systems can be readily used to monitor transient thermal diffusion effects in solids. The object of this paper is to describe todays application techniques of thermography in the non destructive testing field. The paper shows experiences of Florin & Scherler AG, a institute, which only is working in thermal mapping.

In the past, thermography has made few significant in-roads in the area of process and industrial control. Part of the problem has been the high frequency and dynamic range of line and image data that is detected by a thermal imagers and line scanners. For process control applications, this high data rate must be processed in real-time by complex mathematical algorithms which translate radiant energy into temperature, temperature difference, or a function thereof. This paper describes the development of a high speed real time data processing and analyzing system designed for in-plant process control and quality assurance testing. The ability to collect, manipulate and analyze thermal line-data will give supervisory computers and robots the ability to adjust processes on the fly. And, the data can be collected, statistics created and control sheets generated for quality control and manufacturing efficiency evaluations.

The use of infrared non-contact temperature measurement is now an accepted technology in industry; this technology is widely accepted in the chemical, food, pulp and paper, steel and electronics industries, just to name a few. Conventional direct viewing instruments however, have a number of physical limitations which restrict their use in many applications. The utilization of fiber optic based instruments in non-contact infrared temperature measurement has extended this technology into areas considered difficult or impossible prior to the use of fiber optics. Several design considerations of fiber optic temperature monitoring instrumentation will be discussed in this paper along with their unique applications.

Floating method is an advanced teachnology for manufacture of glass plate. In floating manufacture line, the shaping segment is the key part for quality control. The measurement of temperature distribution across the glass plate in this segment is the prerequisite for optimum temperature research and control. In this paper, the possibilily of using infrared vidicon to mesure the temperature distribution of glass plate is analysed. Methods for raising the measuring accuracy are also discussed. Experiment results verify the analysis.

A line of tube transfering 300°C vapour at high pressure has been surveyed by means of thermography to obtain its surface temperature. The tube is 529 mm in diameter. A great number of thermal images are observed and analysed. Heat leakage is shown by much higher temperature area on these thermal images. One can find different causes of these heat leakage, for example, from imperfect parts of insulation meterial around tube, or from the connection gap between block-shape insulation material. A thermal imaging system with capability of digital processing image is used. A practical method to calculate the heat flux density from the image is developed. The program is executed in the same time with the measurement. Such quantitative results may be compared in the field with other ordinary measurements, such as heat flux meter, and enthalpy variation calculation. Over 1.62km distance, a variety of thermal patterns are processed digitally, an average of heat flux density 110 kcal/m2h is obtained, which is in good coincidence with other measurements. Other results, such as the highest and average surface temperaturea,the percentage of heat leakage contribution from different areas, etc., are also obtained. This digital processing method can provide a standard to check the quality of heat insulation. Experiments with different insulation materials are also made, and useful results are obtained from their comparison.

A very high sensitivity scanning radiometer has been developed for remote sensing in the 8-12 μm spectral region. The paper describes this research system which, under computer control, can automatically monitor the thermal emissions from one point or many points within a preselected field of view. The thermal data is displayed either digitally or in the form of graphs or as colour coded thermal maps of the area under inspection. This research instrument offers a highly versatile scanning system combined with a thermal resolution much greater than usually available from current thermographic systems. Furthermore, in addition to point, line and area scans, temperature vs time plots of single points may be produced. Many digitally recorded scans may be stored and quickly recalled for examination. The range of potential uses is wide and it is envisaged that a commercial system based upon this research instrument would be particularly valuable in those applications requiring up to 100x the resolution of typical thermographic systems. The paper reviews the main features of the research system: * high sensitivity detection and processing systems producing temperature resolution better than ±0.002 Kelvin * variable field of view * single point, line scan or area scan operation * display system Objective methods have been developed for analysis of thermal sensing performance. These tests involved the application of specialised thermal test target systems which enable the spatial and noise characteristics of imaging systems to be assessed. The results of preliminary studies using the high sensitivity scanning radiometer are reported; this work includes engineering material studies, thermal detection in electronic components and life-science studies.

Office of the Program Manager for TMDE (OPM TMDE) has initiated a program to develop techniques for evaluating the performance of printed circuit boards (PCB's) using infrared thermal imaging. It is OPM TMDE's expectation that the standard thermal profile (STP) will become the basis for the future rapid automatic detection and isolation of gross failure mechanisms on units under test (UUT's). To accomplish this OPM TMDE has purchased two Infrared Automatic Mass Screening ( I RAMS) systems which are scheduled for delivery in 1987. The IRAMS system combines a high resolution infrared thermal imager with a test bench and diagnostic computer hardware and software. Its purpose is to rapidly and automatically compare the thermal profiles of a UUT with the STP of that unit, recalled from memory, in order to detect thermally responsive failure mechanisms in PCB's. This paper will review the IRAMS performance requirements, outline the plan for implementing the two systems and report on progress to date.

Conformal coatings are applied to most printed circuit boards (PCB's) in use on military programs. They are clear, transparent (to visible light) coatings that help reduce the mechanical effects of vibration and protect the PCB's from moisture and fungus under adverse environmental conditions. It has been a commonly held belief for some time that, from the point of view of thermal imaging, conformal coatings tend to have a high and uniform emissivity in the infrared spectrum and, therefore, provide the PCB's with very close to "blackbody" infrared characteristics. This belief has been challenged recently by investigators who observed indications that MIL specified conformal coatings had far from blackbody characteristics. These characteristics were reported to vary with type, thickness and the wavelength interval (spectral band) measured. In 1985 the US Army Communication Electronics Command (CECOM) initiated the TRAMS (Infrared Automatic Mass Screening) program aimed at the automatic mass screening of PCB's for gross faults at the depot level based on infrared profiles. A conformal coatings investigation was conducted as part of the IRAMS program in order to achieve a better understanding of the effects of conformal coatings on the infrared thermal profiles of PCB's. Predictive investigation was conducted through contact and correspondence with manufacturers and users of conformal coatings. Experimental investigation was conducted by means of measurements using imaging systems operating in different wavelengths and prepared samples with various conformal coating types and thicknesses. This paper describes the work done, the results obtained and recommendations for future measurements.

This paper will discuss the need for correcting IR radiance images for the emissivity at every point, and how this is done in a particular instrument to obtain true temperatures. The possible error due to temperature dependent emissivities is also discussed. Examples demonstrating the effect of emissivity correction in actual applications are presented.

Modern technology and the need for faster systems has resulted in the design and manufacture of printed circuit boards (PCBs) having multiple layers of signal and power cores. The use of surface mounted components having differing operating voltages has dictated the need for PCBs that have both single and multi-voltage internal planes. The present manufacturing processes result in raw PCBs having power to power defects that occur both externally and internally. A need exists for a procedure that can accurately locate these defects. It should allow the capture of the defects with the least exposure of the board to any damage from the investigative and repair operations. Such a procedure, in order to reduce cost and maintain product flow, should be as automated as possible and be capable of being run by personnel from the manufacturing area. This paper deals with an Infrared Thermography application to address this need.

The applications and potential reliability and cost benefits of infrared microimaging are reviewed. Examples of cost savings are presented to help justify investment in infrared inspection technology and tools.

An infrared (IR) measurement technique is described which can be used to detect microwave fields, both continuous wave (CW) and pulsed. The technique involves placing a thin lossy detection screen material in the region over which the electromagnetic (EM) field is to be mapped. The fields are detected through the Joule heating that occurs when EM energy is absorbed by the screen material. When the surface temperature of the screen rises to 0.1 K or higher above the ambient temperature, the induced temperature distribution at the surface of the screen (which corresponds to the EM field intensities in the screen) can be detected by an IR scanning system via emitted thermal radiation. CW measurements by an IR measurement technique have been demonstrated and reported over the past several years. While the technique requires a minimum energy deposition for sufficient heating, the electrical parameters of the detection screen can be selected, such that the thermal mass of the screen is reduced, allowing a faster response. IR data acquisition to a high-speed memory has also been developed to store approximately 500,000 pixels of a two-dimensional IR image in less than three seconds. 5 This corresponds to thirty 128 x 128 frames of data with each pixel element represented as an 8-bit word, which correlates to the electric or magnetic field intensity at that location. As a diagnostic tool, this technique can be used to measure radiated fields and to support tests and evaluations of electronic systems in the presence of EM radiation, e.g., to determine the free-field environments around microwave sources, to determine the energy coupled into electronic circuits through partially shielded enclosures, and to verify hardening techniques. The near, far, and internal fields generated by a microwave horn can be mapped using a thin lossy screen. Apertures in enclosures can be identified by placing a resistive coating on the surface of the metal in the area suspected of containing an aperture. Examples of energy coupled into an electronic circuit and analysis of radiation from antennas are presented. The applications, advantages, and disadvantages of this new infrared technology are also discussed.

Quantifying airborne thermal infrared data has been a problem since the technology was created. A procedure is outlined to describe general ground truth measurements and their purpose. Specific ground truth procedures and equipment are detailed in a sample field deployment. The placement of instruments and equipment is discussed to make the user more aware of potential problems. Instruments utilized are radiometers, meteorological stations, and radiosondes. Equipment used includes reflectance/emittance targets, spatial resolution targets, and a water bath. A brief discussion of the reasons behind acquiring the ground truth data and how the measurements fit into the equations. This helps the ground truth personnel appreciate how small measurement errors can create major problems in the data analysis. The thermal infrared imager has to be characterized in order to quantify the data acquired in the field. A procedure for the characterization of the thermal infrared system response in the 8 micrometer to 13 micrometer band is outlined. The acquisition of data presenting the actual data flights is discussed. The sequence of ground truth data acquisition is presented. Particular attention is paid to acquiring time critical and non-time critical ground truth measurements. Sample data are presented to demonstrate the effect of ground truth measurements on thermal infrared data. The effect on quantifying relative temperature difference and absolute temperature differences is highlighted with respect to inadequate and less accurate data than desired.

Time-dependent temperature distribution data were obtained from cylindrical nylon test specimens deformed in torsion. The temperatures were measured with an infrared radiometer and calculated with image analysis software. These data provide a clear picture of the evolution of the specimen's surface temperature profile prior to and during strain localization and failure. Measurements like these will be used to evaluate parameters in a material model now under development. The data will also help establish the validity of existing numerical methods.

True temperature can be determined from infrared thermography provided the material emissivity and ambient irradiance are known. The measurement equations found in the literature are valid only if the scanner response is linear in radiance. Other complications arise if the emissivity depends on temperature. Spectral (or band) rather than total emissivity values should be used but are less often found in the literature. A new method, specimen calibration, avoids these problems by determining a calibration curve specific to the specimen and experimental arrangement. The computer program VDAS (Video Data Analysis System) automates the collection of calibration data, reduction to a calibration curve, and temperature measurement using the curve. The new method was tested on nylon 6/6 between 20 and 160° C and on 304L stainless steel between 30 and 500° C and was found to be significantly more accurate.

Certain metal combinations alloy, with release of large amounts of energy. Palladium/Aluminum is available commercially in the form of wire, braid and foil of various diameters and thicknesses. These products are useful as heat sources and as fuses to ignite other pyrotechnic compositions. We have found that when used in small devices, where the fuse wire may be required to go through narrow channels and sharp bends, the alloying reaction may not propagate reliably. We have used infrared thermography to monitor heat flow in the fuse wire and in materials surrounding it, to observe the thermal dynamics involved in fuse wire propagation. Fuse wire can be ignited by passing an electrical current through it from end to end or it can be lit from one end to carry ignition to other locations in a device or system. Two effects have been observed thermographically: Conductive cooling of the wire where effective thermal contact occurs and hot zone formation at stress points produced by sharp bends. Thermographic measurements have demonstrated that when electrical current is used to ignite palladium/aluminum wire or braid, reaction begins farthest from a heat sink region, or at a sharp bend.The problem with high thermal contact is easily understood since heat sinking can cool the fuse wire and retard reaction, even to the point of failure. Hot zone formation at high stress regions may, on the other hand, not appear detrimental. However, if one recognizes that these hot zones result from high electrical resistance, probably due to microscopic cracks formed in the palladium sheath of the fuse wire, it is easy to see that a corresponding thermal resistance will also be present. Such a high thermal resistance point, when coupled with adjacent conductive cooling paths can contribute to fuse failure.By using infrared scanning, one can not only observe the importance of such effects in fuse wire ignition and propagation but also see where they may be occurring in a particular configuration. Possible failure points can thus be avoided in device designs.

To a friction material manufacturer, temperature measurement is of extreme interest because the distribution of heat generated during braking is not well behaved. This heat is one of the most important factors in altering friction level and wear characteristics. There are several general classes of temperature measurement methods commonly used to test friction materials. There are also more sophisticated systems which sense infrared radiation and convert it to temperature. When used as the infrared equivalent of television, these systems are useful in measuring the surface temperature of stationary or slowly moving objects. When testing friction materials, the surfaces of interest are rapidly moving and often shaped so they cannot be viewed in total from a single location. When this surface cannot be "photographed" as such, the temperatures must first be encoded as a data stream and then decoded. There is no longer a "television" picture and the data are of sufficient density as to require a computer to collect and to use a finite element analysis type program after the conversion to temperature. Thermal maps can be made of the surface of interest using color graphics and, in addition, numerical methods such as histograms can also be used. This technique was developed by the end user because it was not commercially available and has been very valuable in determining several friction material characteristics.

Analysis of pressure distributions on skis while skiing is of interest to ski researchers in that it yields useful information on ski design parameters such as spring constant, damping, and dimensional shape in a dynamic environment. Obtaining pressure distribution data on skis while skiing is a complex task due to the amount of instrumentation required and mobility of the skier. Research has been performed on analyzing pressure distributions from skiers on a ski deck using infrared thermography. The ski deck offers a platform where the skier is stationary and the deck (carpet) moves under the skier. As the skier skis on the revolving ski deck carpet, thermal patterns are observed behind the skier on the carpet surface. The intensity of these thermal patterns are proportional to the temperature rise on the deck surface and the pressure applied by the ski bottom to the deck surface. Several thermograms were analyzed for different skiing turns ranging from basic wedge turns through advanced linked turns. Transient pressure distributions are presented for various maneuvers. Infrared thermography coupled with revolving ski deck technology has been used to qualitatively depict ski pressure distributions for ski instructors teaching students how to ski. This has resulted in a quicker and safer learning process. The technique can also be used as a quantitative tool for the analysis of newer and safer ski designs.

Two-color radiometry is a well-known technique for temperature measurement and is routinely used in such applications as astronomy and photography. We have applied the technique in some new ways for determination of the ensemble graybody temperature and the matter distribution in plumes of solid products of pyrotechnic reactions in vacuum. Each resolution element of interest is measured simultaneously in time and space at two different wavelengths and the desired results derived. A commercially available two-color imaging radiometer provides sufficient resolution in the temporal, spectral, and spatial domains for our application. We measure to useful accuracy temperature in the 400°C to 1200°C range and ensemble emissivities ranging from 10-1 to 10-4 in plumes produced pyrotechnically. Optical bandpass changes in the sensor, special calibrations, and special computer codes to achieve these results are described.

A new thermal imaging system based on double color principle is described in this paper. It only requires one senor and one channel, so various affecting factors on measuring accuracy are automatically eliminated, with additional advantages of keeping the compatibility industrial T.V. Both theoritical analysis and technical programme are presented.

Arc-plasma spraying is a process used to coat parts with thermal barriers, near surfaces, non-corrosive layers, and to form free standing parts. This process involves depositing liquid materials on a surface by passing particulates through a high temperature > 20,000°C plasma. Molten particles impinge the surface and rapidly solidify to form a bonded composite.

Pyrophoric fuels are under investigation at Defence Research Establishment, Valcartier, Quebec, Canada as new infrared (IR) emission sources. A thermal imaging radiometer (TIR) is used to obtain radiance values in the 3- to 5-μm spectral region. Pyrophoric/air flames are generated under windspeeds varying from Mach 0.3 to Mach 0.9. The infrared images recorded on tape during trials are analysed in the laboratory with the use of an 8-bit image processing system. False color enhancement can be provided for high-radiant intensity regions of the flames. The raw images show flame edges that are not well defined. In order to improve accuracy on the determination of flame area, multi-frame images are used. Procedures for image acquisition, calibration and treatment will be discussed in this presentation.

This paper developes the optics of heat conduction in solids by analogy, progressing from a physically justified foundation to a complete parallel with geometrical and physical optics. As a consequence, a wholesale adaptation of optical theory and technology to the conduction of heat in solids becomes possible, with many applications to thermography. The analogy includes a detailed heat transfer analogue of double refraction in thermally anisotropic materials,which are assuming a greater role in fabrication of high technology aircraft.

A technique is presented which uses an infrared camera and a computer system to determine the true temperature distribution on close up plane targets, and emittance and transmission distribution can be calculated pixcel by pixcel from multiple IR images in different condition. Four experiments were performed to verify the technique on opaque objects, and the results were in close agreement within 5% error of the infrared camera system. The conditions to achieve this result were: 1) the measurements were made in some rooms with uniform set temperature, 2) one reference image at a uniform temperature distribution, eg. at room temperature in thermal equilibrium condition, is required for each opaque sample, and 3) the references should be the same sample at same location exactly. For transparent material, though the principle is the same, the measurement is much more complicated than the opaque material. One more condition is needed for this measurement, that is, two reference image with uniform set temperature together with uniform and a controllable radiation source behind the sample are required to determine the transmission distribution, emittance distribution and true temperature distribution of transparent samples, in addition to the conditions for opaque objects.

The American Heritage Dictionary defines ethics as "The general study of morals and of specific moral choices to be made by the individual in his relationship with others". A code of ethics defines these moral relationships to encourage integrity throughout a profession. A defined code of ethics often yields credibility to an organization or association of professionals. This paper outlines a proposed code of ethics for practitioners in the infrared thermographic field. The proposed code covers relationships with the public, clients, other professionals and employers. The proposed code covers credentials, capabilities, thermograms, compensation and safety.

Standard methods are necessary to assure the quality of infrared roof moisture surveys. An ASTM C 16.30 task group is currently working on the first draft of a Standard Practice for the location of moisture in insulated roofing system using infrared thermography. The Standard Practice will address procedures for both aerial and ground-based surveys. Additionally, instrument requirements, types of applicable constructions, operator qualifications, environmental and substrate conditions, as well as data interpretation, verification and reporting requirements will be outlined. The result is intended to be a practice which, if followed, will ensure roof moisture surveys of consistent quality.

Bibliography Of NDT Of Composite Performed With Infrared Thermography

Lack of reliable operational methods makes it difficult for potential users to benefit from infrared survey systems which are already well tested technically. In order to develop operational routines for the use of thermography for building and district heating network applications, airborne, mobile and handheld infrared systems have been tested in two different investigation areas. Provided that perturbing factors were taken into consideration and surveys were made during stable weather conditions, with low windspeed, the infrared system tested was found to have good accuracy and low operational cost. An aircraft equipped with an infrared line scanner (8-14 μm) seems to be the best system for surveying larger areas, while helicopter and mobile thermovision systems (8 - 14 μm), are preferable for smaller investigation areas. The best way to analyze thermograms seems to be with an interactive computer-based image analysis systems.