IR monitoring is a basic tool for quality control and predictive maintenance in the paper industry. There are also other possible interests, e.g. measurements of temperature profiles of high speed production lines. The first possibility to use IR for the above mentioned use appears to be applications of glass heat treatment in on line production. At this time there is a lot of interest to be able to measure temperature profiles from a fast moving surface (e.g. in paper machines) with velocities like 10 - 20 m/s. Normal low speed line scanners typically give scanning speed of 50 Hz which in this case means 20 m/s/50 Hz equals 40 cm resolution. The obtained resolution is not normally high enough. To have more accurate vision from the studied surface IR camera line scanning was proposed to be a solution with line scanning frequencies of 8000 Hz which would provide resolution of 20 m/s/8000 Hz equals 0.25 cm between surface points. It is a well-known fact that all undesired frequencies in paper transfer systems disturb the uniform paper drying process which in some cases is the basic reason for low quality coating or even broken paper line. The possibility to detect these drying problems with IR frequency analysis will give a new way to control the paper drying process. With IR analysis it is possible to get information about temperature distributions along the paper track. Using a well established frequency analysis as a tool, the error estimations are obtained. In most cases an open-roll image from paper track is very desirable because there are no existing wide area measurement systems for this purpose. The careful analysis of this new method is given in the manuscript.

Infrared thermal analysis is used to characterize and optimize injection moulding and blow moulding of plastic parts colored with 2 - 4% carbon black. Thermographic and ultrasonic data show that during injection moulding shrinkage of the plastic in the mould creates a gap between the part and mould which produces a thermal contact resistance thereby reducing the cooling efficiency of the mould. The effect of shrinkage was minimized by using high packing pressures. Thermal analysis of blow moulding provides evidence of a 'skin' on the surface of the parison which affects the wetting of the part and mould. A high blow rate is required to maintain a parison that wets the mould surface well to promote the transfer of heat out of the part. In addition, under fixed operating conditions. The temperature field on thin walled parts can be used to obtain on-line thickness distributions and measure blow ratios. Results of the study have been applied to the analysis of automotive parts.

A protocol for infrared thermal analysis of die surfaces is proposed. The most suitable infrared camera has a spectral response in the 8 - 10 micrometer of the infrared spectrum as the emissivity is higher and more uniform across the surface of the die than in the 3 - 5 micrometer region of the spectrum. Through the prudent use of shielding, die surface temperatures can be measured, thermal gradients are detected, the effectiveness of cooling lines can be evaluated and spray patterns are optimized. The technique is not suitable for examining aluminum parts as the emissivity of aluminum is low and the optical properties of the surface oxide layer change as the part cools.

Hydraulic systems are the life blood of many industrial processes, especially the many forming presses used in the automotive industry. The loss of a press due to a hydraulic system failure can be very expensive, both in terms of reduced machine availability and diminished product quality. Thermography has proven to be an excellent maintenance inspection tool because the performance of hydraulic systems are easily characterized by their thermal signatures. Thermography also provides instantaneous, real time thermal data which is essential to understanding a dynamic system like hydraulics. This paper, based on many of Milan Plastics' six years of experience with hydraulic systems, outlines the key components that can be inspected with thermography and discusses problems that are typically found.

DuPont is one of the world's largest petrochemical firms. Infrared thermography has been a key nondestructive test method used in the predictive/preventive maintenance (PPM) areas for many years. This paper discusses the reasons why DuPont chooses to use the qualification and certification standards of the American Society for Nondestructive Testing (ASNT) to establish a certification program for thermographers.

Written inspection procedures are an essential element of acquiring valid data on a repeatable basis. They are also vital to the safety of the thermographer, and may, for that reason alone, be required by a company or regulatory agencies. Many thermographers are working with either no procedures or procedures that have not been developed specifically to meet their needs. To date only a few of the necessary procedures have been developed by recognized standards organizations. The lack of procedures is limiting the use of thermography. Where the technology is being used without procedures, results are often less than optimum. This paper (1) surveys existing procedures and standards; (2) discusses current efforts by standards organizations to develop standards and procedures; and (3) presents a general methodology from which written inspection procedures can be developed for many thermographic inspections.

Every third child and many adults in Sweden have allergic reactions caused by indoor environmental problems. A lot of buildings constructed during the building-boom period of 1950 - 1990 expose the sick-house-syndrome, due to built-in moisture problems and poor ventilation performance of the building. Leaky building construction, transport of humid air condensing on thermal bridges within the construction gives rise to a humid environment, and forms a base for a microbial deterioration process of organic materials, with emissions hazardous for human health. So far there are no universal and cost efficient techniques or methods developed which could be used to reveal the sick-house-syndrome. In this paper we present the results of a case-study of the sick-house-syndrome, and an investigation concept with a combination of different techniques and methods to detect and to map underlying factors that form the base for microbial activities. The concept includes mobile and indoor thermography, functional control of ventilation systems, tracer gas techniques for measurement of air flow exchange rate in different rooms, microbial investigation of emissions, field inspections within the building construction and the building envelope, and medical investigation of the health status of the people working in the building. Mobile thermography of the exterior facades has been performed with a longwave AGEMA THV 900, respectively THV 1000 infrared system, during the period December 1994 - June 1995, at different and similar weather and radiation conditions, and with the building pressurized at one accession. Indoor thermography has been performed with a shortwave AGEMA THV 470 system, for a selection of objects/surfaces with thermal deviations, indicated in thermograms from the different mobile thermographic surveys. Functional control was performed for the ventilation systems, and air flow rates were measured using tracer gas technique for a selection of rooms with different function, manload and demand of air flow. Field control inspections were performed partly from the inside and partly from the outside of the building. Microbial activities were investigated by traditional measurements of the emissions and contamination of indoor air, and by ocular inspections and laboratory tests of building materials. Despite the fact that the building studied has a complicated composition of surface materials, including glass, wood, steel and concrete panels, it was possible to indirectly indicate surface anomalies, related to microbial deterioration of organic materials, through mold and rot activities, due to in-exfiltration of humid air, causing moisture problems within the construction. The result from this case-study shows that thermography can become an important diagnostic tool in order to detect and map sick-house-syndromes. The project is to be continued.

For more than 20 years, infrared thermography has been used in the study of energy loss in residential buildings. Early application of the industry acknowledged the problem of technology transfer. That is, the information gained from infrared thermography needed to be interpreted and translated down to the actual construction trades. By utilizing the information gained from an infrared thermographic survey, with a blower door, improvements in new construction design have been realized and implemented. The approach involved the use of infrared thermography and blower door testing in assessing the thermal capabilities, insulation quality, comfort level and air infiltration rate of each unit. Randomly selected model and production units were used to obtain information. Visual inspections were conducted while the homes were under construction to verify the quality and method of construction practices. Infrared and blower door tests were conducted upon completion of construction. The results of these studies were reviewed with the builder and where practical, incorporated into future design and construction practices. This enabled the builder to offer the homeowner a substantial improvement in operating costs and increase the builder's reputation for quality construction.

This paper compares experimental results obtained on ancient buildings, following the usual qualitative inspection with a procedure based on time-domain analysis. The aim of the project was to study relationships between characteristics of defects and thermal behavior of the surface, using thermal scanning in various conditions. The other topic was to prove generally the usage of solar radiation as a heating source in thermal scanning. The 'Palazzo della Ragione' in Milan is more than 700 years old. We gave our attention to the upper part of the building. The conditions and damages of facades have been studied also using knocking tests. Defects we are looking for are delamination of plaster on the brick wall. The southward facade has been monitored 6 times during 1993 - 1995, using thermography. In addition, the actual weather conditions during scanning were measured. The results were qualitatively analyzed. A lot of knowledge is needed for the qualitative interpretation of thermograms, because different kinds of defects and structure variation may be confused. Because of limiting factors, any clear correlation between the temperature changes and the detected damages of coating cannot be found based on the first approach. A new series of tests has been made in October 1995. Experiments have been carried out also at a laboratory on a segment of wall, including known defects at various depth. A numerical simulation of the temperature pattern and its time evolution, during the heating and cooling of the wall, was also performed. The dynamic test has been planned, based on the experience of these preliminary studies. Experimental and simulated data have been compared for laboratory and in situ dynamic tests.

As infrared thermography has become an accepted discipline in the field of predictive maintenance, it has also been used in conjunction with other technologies to provide a total perspective of the operating condition of equipment and processes. Infrared is now being integrated with technologies such as global positioning systems (GPS), to provide much more comprehensive information in both the forest industry and electrical distribution industry. With these applications it is not only important to identify hot spots that are potential problems but it is also necessary to in some way document the exact location of the anomalies.

Fuel accounts for an average of seventy percent of the yearly operational and maintenance costs of all the fossil stations in the United States. This amounts to 30 billion dollars spent for fuel each year. In addition, federal and state environmental codes have been enforcing stricter regulations that demand cleaner environments, such as the reduction of nitrogen oxides (NOx), which are a by-product of the fossil fuel flame. If the burn of the flame inside a boiler could be optimized, the usage of fuel and the amounts of pollution produced would be significantly reduced, and many of the common boiler tube failures can be avoided. This would result in a major dollar savings to the utility industry, and would provide a cleaner environment. Accomplishing these goals will require a major effort from the designers and operators that manufacture, operate, and maintain the fossil stations. Over the past few years re-designed burners have been installed in many boilers to help control the temperatures and shape of the flame for better performance and NOx reduction. However, the measurement of the processes and components inside the furnace, that could assist in determining the desired conditions, can at times be very difficult due to the hostile hot environment. In an attempt to resolve these problems, the EPRI M&D Center and a core group of EPRI member utilities have undertaken a two-year project with various optical manufacturers, IR manufacturers, and IR specialists, to fully develop an optical lens that will withstand the high furnace temperatures. The purpose of the lens is to explore the possibilities of making accurate high temperature measurements of the furnace processes and components in an ever-changing harsh environment. This paper provides an introduction to EPRI's internal boiler investigation using an IR high temperature lens (HTL). The paper describes the objectives, approach, benefits, and project progress.

Infrared thermography is a remarkable aid in maintenance, and has been used for a number of years in testing high-voltage lines and transformer substations. Electricite de France (EDF) has developed a special infrared thermography system for this type of application. Until recently, use of IRT in both fossil and nuclear power plants was only sporadic and depended on the interest shown in the technique by individual maintenance managers. In power stations, it was primarily used for tests on switchyards, electrical control cabinets and insulation. The General Engineering Department of the EDF Generation and Transmission Division was responsible for assessing new equipment and studying special development requirements as they arose. Routine infrared thermography tests were performed by two teams from the Division, one handling northern France and the other southern France. Today, infrared thermography has become a fully-fledged monitoring and diagnosis tool in its own right, and related activities are being reorganized accordingly. Its recent success can be attributed to a number of factors: more high-powered IRT techniques, valuable feedback from American utility companies, and technical and economic assessments conducted by EDF over the last two years on equipment such as electrical and mechanical components, valves and insulation. EDF's reorganization of infrared thermography activities will begin with an overview of the resources now existing within the company. This inventory will be carried out by the General Engineering Department. At the same time, a report will be drawn up bearing on IRT testing over the last decade in conventional and nuclear power plants in France and the United States. Lastly, EDF will draw up a list of components to be monitored in this way, essentially on the basis of RCM studies. These measures will provide power plants with a catalogue of infrared thermography applications for specific component/failure combinations.

This paper describes and reports the findings of a study performed by the Miller Brewing Company. The researchers assembled a test bed consisting of a motor and generator linked by seven different interchangeable flexible couplings. They then misaligned the motor and generator and used different predictive technologies to monitor any coupling changes.

Infrared thermography has been used routinely in industrial applications for quite a long time. For example, the condition of electric power lines, district heating networks, electric circuits and components, heat exchangers, pipes and its insulations, cooling towers, and various machines and motors is monitored using infrared imaging techniques. Also the usage of this technology in predictive maintenance has proved successful, mainly because of effective computers and tailored softwares available. However, the usage of thermal sensing technique in fluid power systems and components (or other automation systems in fact) is not as common. One apparent reason is that a fluid power circuit is not (and nor is a hydraulic component) an easy object of making thermal image analyses. Especially the high flow speed, fast pressure changes and fast movements make the diagnosis complex and difficult. Also the number of people whose knowledge is good both in thermography and fluid power systems is not significant. In this paper a preliminary study of how thermography could be used in the condition monitoring, fault diagnosis and predictive maintenance of fluid power components and systems is presented. The shortages and limitations of thermal imaging in the condition monitoring of fluid power are also discussed. Among many other cases the following is discussed: (1) pressure valves (leakage, wrong settings), (2) check valves (leakage); (3) cylinders (leakage and other damages); (4) directional valves and valve assemblies; (5) pumps and motors (leakage in piston or control plate, bearings). The biggest advantage of using thermography in the predictive maintenance and fault diagnosis of fluid power components and systems could be achieved in the process industry and perhaps in the commissioning of fluid power systems in the industry. In the industry the predictive maintenance of fluid power with the aid of an infrared camera could be done as part of a condition monitoring of other systems, for instance bearings.

Infrared thermography has been shown to be very effective in revealing damage in glass fiber composite boat hull structure for both solid laminate and foam core construction hulls. This paper addresses some of the parameters which can impact the effectiveness of the infrared thermal approach for these applications. Effects associated with surface condition, viewing angle, field-of-view, heat source type and intensity, and other conditions are discussed. An approach to providing a simple demonstration of the particular test approach is also discussed.

This paper describes an approach to planning and performing nondestructive testing (NDT) on a structure. It applies to NDT in general, but it is most relevant to inspections of large composite structures using thermographic NDT (TDNT) and other imaging NDT techniques in which defects are detected by pattern recognition or image analysis. Realistic problems are listed.

A nondestructive technique for the quantitative evaluation of defects in metal structures is described. The surface of the metal is irradiated by a short xenon lamp pulse and monitored by a thermal image processor. The analysis relates to the time decay signal of the front face temperature, which contains information on the thermophysical properties and subsurface defects of the material. The time history of the surface temperature is then used to quantify the substructure of the material. Applications for the inspection of aluminum, steel, and turbine blades are presented.

Recent advances in thermal imaging technology have spawned a number of new thermal NDE techniques that provide quantitative information about flaws in aircraft structures. Thermography has a number of advantages as an inspection technique. It is a totally noncontacting, nondestructive, imaging technology capable of inspecting a large area in a matter of a few seconds. The development of fast, inexpensive image processors have aided in the attractiveness of thermography as an NDE technique. These image processors have increased the signal to noise ratio of thermography and facilitated significant advances in post- processing. The resulting digital images enable archival records for comparison with later inspections thus providing a means of monitoring the evolution of damage in a particular structure. The National Aeronautics and Space Administrations's Langley Research Center has developed a thermal NDE technique designed to image a number of potential flaws in aircraft structures. The technique involves injecting a small, spatially controlled heat flux into the outer surface of an aircraft. Images of fatigue cracking, bond integrity and material loss due to corrosion are generated from measurements of the induced surface temperature variations. This paper presents a discussion of the development of the thermal imaging system as well as the techniques used to analyze the resulting thermal images. Spatial tailoring of the heat coupled with the analysis techniques represent a significant improvement in the detectability of flaws over conventional thermal imaging. Results of laboratory experiments on fabricated crack, disbond and material loss samples are presented to demonstrate the capabilities of the technique. An integral part of the development of this technology is the use of analytic and computational modeling. The experimental results are compared with these models to demonstrate the utility of such an approach.

A thermal projector design is discussed as implemented to perform forced diffusion thermography. The system projects a continuous dynamic pattern of heat in order to drive thermal conduction across flaws. The simple projector utilizes a conventional 625 watt incandescent source and a servo-controlled mirror system to create a simple moving line pattern of heat. Although the system is capable of detecting a variety of flaws, it is most suited for crack detection. Projector design and results are presented.

A data analysis procedure is described to enable quantitative information about defect depth and surface and subsurface thermal properties to be obtained from the time series of images acquired in a time-resolved infrared radiometry (TRIR) measurement. While the approaches described have been previously considered for single point measurements, in this work the algorithms are applied to full field images. As a result, images presenting defect depth and amount of thermal mismatch at subsurface interfaces can be constructed. Results are presented for composite test panels with flat-bottomed holes milled to different depths, two-layer specimens with differing thermal properties between the top layer and the substrate and a graphite/epoxy-honeycomb composite panel with simulated delaminations.

The thermographic inspection of materials and structures typically involves the application of a heat flux to the surface and measuring the subsequent surface temperature profiles. The nature of typical heat flux sources requires the incident flux has the shape of either a short pulse or a step function. This pulse shape for the flux typically will not maximize the contrast between a response from a flaw in the structure and the unflawed regions of the structure. Optimal shaping of the pulse is experimentally difficult, if not impossible. However, its consideration serves as a useful tool for developing post-processing techniques for the data. The concept is to design filters for processing the data in a manner that emulates shaping the input flux. Convolving the measured thermal response with this optimized filter effectively maps the measured response to the response for an optimally shaped input heat flux. A method for generating this filter is presented. Applying the filter to the thermal response of the structure increases the contrast between flawed and unflawed regions. Results with experimental data illustrate the advantages of the technique over conventional techniques.

We describe a thermal wave technique for making defect depth determinations. Both theory and experiment are presented, and the results are compared. Examples of defects having different lateral dimensions and boundary conditions are given.

A technique by which subsurface thermal inhomogeneities can be quantitatively reconstructed from photothermal images is discussed. The approach is based on the fact that the photothermal signal can be expressed as the spatial convolution of the photothermal point spread function and the shape function of the hidden object. Numerical simulations demonstrate the performance and the limits of the approach. Experimental results obtained from a low thermal contrast sample are presented and compared with the theory.

Ceramic matrix composites are being developed for numerous high temperature applications, including rotors and combustors for advanced turbine engines, heat exchanger and hot-gas filters for coal gasification plants. Among the materials of interest are silicon-carbide-fiber- reinforced-silicon-carbide (SiC_(f)/SiC), silicon-carbide-fiber-reinforced-silicon-nitride (SiC_(f)/Si₃N₄), aluminum-oxide-reinforced-alumina (Al₂O_3(f)/Al₂O₃, etc. In the manufacturing of these ceramic composites, the conditions of the fiber/matrix interface are critical to the mechanical and thermal behavior of the component. Defects such as delaminations and non-uniform porosity can directly affect the performance. A nondestructive evaluation (NDE) method, developed at Argonne National Laboratory has proved beneficial in analyzing as-processed conditions and defect detection created during manufacturing. This NDE method uses infrared thermal imaging for full-field quantitative measurement of the distribution of thermal diffusivity in large components. Intensity transform algorithms have been used for contrast enhancement of the output image. Nonuniformity correction and automatic gain control are used to dynamically optimize video contrast and brightness, providing additional resolution in the acquired images. Digital filtering, interpolation, and least-squares-estimation techniques have been incorporated for noise reduction and data acquisition. The Argonne NDE system has been utilized to determine thermal shock damage, density variations, and variations in fiber coating in a full array of test specimens.

By using similarities between the diffusion equation and the wave equation it is shown that one can transform between solutions in one type of propagation to the other. The method is based on the similarities of the Laplace transform between the diffusive and the nondiffusive cases. In the diffusive case, the equation involves the Laplace variable s in the first power while for the nondiffusive cases, similar equations occur with s². Four alternative implementations are developed. The first implementation is based on substitution s² for the Laplace transform variable s using forward and inverse numerical Laplace transform. The second implementation is based on expanding the diffusive time response on exponential time base and replacing it with its image function in the wave case, namely sinusoidal function. The third implementation is based on direct transformation in the time domain using exponential time interval sampling. The fourth one which is optimized for thermal NDE is performed by singular value decomposition.

Nondestructive evaluation by active infrared thermography allows detection of subsurface defects. In some instances however, such defect detection is perturbed by the geometry of the object. Thermal variations caused by object shape alter significantly the detection's performance because it may become difficult to distinguish between a defect and a shape variation (especially if a single image is analyzed). This paper presents a method which allows, from a single infrared image acquired right after the pulse thermal stimulation, to evaluate the shape of a nonplanar object and then apply a correction on subsequent thermograms in the time sequence in order to increase the reliability of defect detection.

The attempt to classify and discuss the terminology used in Thermal/Infrared Nondestructive Testing is made. The table of related terms with definitions and references is available.

When the card-level tester for the F-16 flight control panel (FLCP) had been dysfunctional for over 18 months, infrared thermography was investigated as an alternative for diagnosing and repairing the 7 cards in the FLCP box. Using thermal imaging alone, over 20 FLCP boxes were made serviceable, effectively bringing the FLCP out of awaiting parts (AWP) status. Through the incorporation of a novel on-the-fly neural network paradigm, the neural radiant energy detection system (NREDS) now has the capability to make correct fault classification from a large history of repair data. By surveying the historical data, the network makes assessments about relevant repair actions and probable component malfunctions. On one of the circuit cards, a repair accuracy of 11 out of 12 was achieved during the first repair attempt. By operating on the raw repair data and doing the network calculations on the fly, the network becomes virtual, thus eliminating the need to retain intermediate calculations in trained network files. Erroneous classifications are correctable via a text editor. Erroneous training of neural networks has been a chronic problem with prior implementations. In view of the current environment of downsizing, the likelihood of obtaining functionality at the card-level tester is remote. Success of the imager points to corresponding inadequacies of the automatic test equipment (ATE) to detect certain kinds of failure. In particular, we were informed that one particular relay had never been ordered in the life of the F-16 system, whereas some cards became functional when the relay was the sole component replaced.

A commercially available imaging infrared radiometer, an Inframetrics 760 system, was subjected to simulated space and Martian environments in JPL's 25 ft and 10 ft space simulators for a total of 108 hours. Initially, the IR camera was integrated with the Satellite Test Assistant Robot (STAR) system which demonstrated successful operation in late 1994. During this initial demonstration, the IR camera experienced 24 hours of a hard vacuum with simulated space temperatures between minus 190 degrees Celsius to plus 25 degrees Celsius. Subsequently, the IR camera was subjected to 12 hours of a simulated space and 72 hours of a simulated Martian environment during the Mars Rover test. Equipped only with thermostatically controlled heaters to prevent undercooling, the IR camera operated continuously during these periods and provided numerous images of the simulator interior, a reference target, and the Mars Rover. The reference target consisted of nine samples of different materials used in typical aerospace thermal designs. The emittance range covered 0.02 to 0.90. The target temperature range was varied from minus 80 degrees Celsius to 55 degrees Celsius. The IR camera was reliable and provided quality images throughout this range but measurement accuracy was a strong function of target temperature and emittance. Best results for high emittance targets were within 12 degrees Celsius at minus 80 degrees Celsius to within 1 degree Celsius at plus 55 degrees Celsius.

Complex (magnitude and phase) measurements of the near field of a radiating antenna over a known surface (usually a plane, cylinder, or sphere) can be used to determine its far-field radiation pattern using near-field to far-field Fourier transformations. Standard gain horn antennas are often used to probe the near field. Experimental errors are introduced into the near-field measurements by mechanical probe position inaccuracies and electrical probe interactions with the antenna under test and probe correction errors. A minimally perturbing infrared (IR) imaging technique can be used to map the near fields of the antenna. This measurement technique is much simpler and easier to use than the probe method and eliminates probe position errors and probe correction errors. Current IR imaging techniques, which have been successfully used to rapidly map the relative magnitude of a radiating field at many locations (mXn camera pixels per image captured) over a surface, however, suffer from an inability to determine phase information. Absolute magnitude and relative phase data can be obtained by empirical or theoretical calibration of the IR detector screens (used to absorb the radiated energy over the measurement plane) and by using techniques from microwave holography. For example, magnitude only measurements of the radiating field of an antenna at two different locations (over two different surfaces) in the near field of the antenna can be used to determine its complex (magnitude and phase) far-field radiation pattern using plane-to- plane (PTP) iterative transformations. This paper discusses the progress made to data in determining both magnitude and phase information from IR imaging data (IR thermograms); thus, enabling near-field and far-field measurements of antenna patterns using IR thermal imaging techniques.

The general problem of extracting the correct emission factor from broadband radiometric measurements on non-gray samples is treated with emphasis on polycrystalline beryllium oxide and BeO with a coating of silicon. These samples exhibit a strong spectral variation in their emittance functions where the Planck function has large weight. Under these circumstances the band-averaged emission factor will be temperature dependent, even if the spectral emittance is temperature independent. The consequences of this for the conventional expression which includes a correction for radiance from the surroundings reflected by the sample are investigated. It is concluded that the observation of a temperature variation in this emission factor not only violates an assumption of the derivation, it is also a criterion indicating that the numerical value is incorrect Two algorithms, based on linearization and iteration of the temperature variation are introduced and applied to an emittance step model and the experimental radiometer values for the reststrahlen band materials. It is found that the emission factors obtained after this correction procedure are in significantly better agreement with values obtained from weighted integration of spectral emittance over the spectral window of the radiometer. The room-temperature value of the upper TIR emission factor is 0.40 and 0.22 for BeO and the Si-BeO double layer respectively. A sand-blasted aluminum sample had almost perfectly gray emittance and the emission factor is 0.39 and temperature independent.

The algorithms are produced from the analytical solutions of the three-dimensional spatial- temporal problem of conversion of the boundary conditions, which were derived earlier. Numerical and laboratory experiments to reconstruct the laser beam intensity distribution with the arbitrary spatial distribution from the temperature field of the heated surface were carried out.

Thermographic NDT, which is a technique in NDT based on the surface temperature distribution in heated solids, was applied for the inspection of locally damaged CFRP plate samples under the lateral contact loading followed by cyclic bending. A singular method and an insulation method were examined. The singular method, in which a heat concentration at flaw tips was detected under resistive heating by electric current, was found to be sensitive to the failure, fracture or break in carbon fibers. On the other hand, the insulation method, in which the perturbation in the surface temperature distribution was detected under stream heating by hot air, was found to be successfully applicable to the inspection of the subsurface delamination damage in CFRP. The detected damages by the thermographic NDT were compared with those observed by SAM (scanning acoustic microscope).

Analysis offriction in binding systems has been a subject of interest to researchers and binding manufacturers. During the ski binding release process, frictional energy is dissipated on anti-friction devices, toe or heel lugs and other components that contact the boot prior to release. The energy dissipation patterns are readily observable using infrared thermographic means. Several tests were performed on a ski binding/boot system under combined as well as pure torque loading. Thermal patterns are presented and interpreted. Thermal signatures on anti-friction devices under combined loading are significantly different from that ofpure torque loading. Snowboard binding systems were also analyzed as to energy dissipation during flexing and extension modes. Energy dissipation in the polymer binding material yields information as to the extent of bending in the binding material. Also, thermal signatures from rubbing ofboots in the binding is readily apparent. Thermograms are presented illustrating highly stressed areas in the binding as well as indicators offuture wear in the binding systems. Infrared thermography is a useful research tool in analyzing the effects ofboots on both ski and snowboard binding systems. Keywords: binding friction, binding release, ski binding/boot system, thermal signatures, snowboard binding/boot system, energy dissipation, polymer binding material, infrared thermography, binding stressed areas, binding wear.

Ski lift tower cable sheaves are a maintenance item in that the sheave bearings must be lubricated periodically. Like most other bearings, wear-out failures can occur. Many times the temperature rise ofthe bearing over ambient is a leading indicator ofa bearing failure. Excessive temperature rise due to increased friction in the bearing often precedes any indication ofvibration or dimensional anomalies. Tests were perfonned using two readily available remote temperature sensing devices, the spot imager and scanning infrared camera. Temperature rise data is presented along with a discussion of temperature measuring techniques. Results show that infrared remote sensing is a cost effective means ofchecking the status oflift tower rotating machinery. Keywords: ski lift towers, ski lift tower sheaves, ski lift tower maintenance, bearing friction, bearing failure, infrared camera, infrared spot imaging, temperature rise data, ski lift tower rotating machinery.

An experimental study of detecting flash temperature spots of reciprocating interface was conducted to visualize and analyze under dry friction by means of the infrared radiometer. The two dimensional temperature distribution of the plane friction interface is displayed on the CRT of the infrared radiometer. We used the dry friction material in combination of the polyoxymethylene materials (POM). The temperature and friction force of the friction interface were measured and recorded in the data recorder. The transient temperature distribution of the reciprocating interface was continuously measured and recorded by the infrared radiometer. It was observed that the excess flashing zone of both side surfaces is alternatively changing its position according to the generation rate of the wear powder in the lateral direction.

This paper contains inspection results for a carbon epoxy plastic reference specimen with Teflon^TM inserts. A long-pulse heating technique and AGEMA-900 IR imager have been used. Results are presented as a set of twenty-two images including a source image, normalized image, timegram, depthgram, tomogram presented as B&W and color hard-copies, as well as live images on a color monitor. This set of data has been exhibited to operators (experts or not) together with the set of rules for detecting defects. Obtained data are processed statistically and compared with true defect locations. The Tanimoto criterion is used for data comparison. Recommendations on the best image processing technique, as well as on the best form of data presentation, are given.

Thermal imaging systems that are used in quantitative applications such as pyrometry or pulsed thermography must be calibrated to provide accurate and repeatable measurements. Several approaches are possible ranging from simple linear calibration to the characterization of detector response using polynomial relationships. This paper describes the application of these calibration techniques to a thermal imaging microscope that must operate over a broad, rapidly changing temperature range while remaining sensitive to small variations in surface temperature. Such an application requires the ability to change the infrared camera exposure and associated calibration parameters quickly. It also requires a method to compensate for variations in background thermal radiance due to the optical configuration of a thermal imaging microscope.

This paper describes the infrared technique used to measure the rapid temperature rise of aluminum and graphite epoxy targets when irradiated by 256 MeV proton beam. In this experiment an infrared scanner with a computer image processor and a special video recorder were used to measure real time-2D temperature distributions as the target was bombarded by 100-500 microsecond pulses of 256 MeV protons. The events were stored both in digital and analog format, for accurate quantitative analyses. The targets were placed in a vacuum chamber, and the surface was monitored through a 32.4 cm diameter by 3.8 cm thick salt window having a 10 micrometer antireflection coating. The experiment was conducted at Los Alamos National Laboratory in New Mexico.