Showing papers on "Thermography published in 1981"
01 Feb 1981
TL;DR: In this paper, the use of commercial infrared sensing equipment was explored as a means of real-time monitoring of weld metal cooling rate, which is known that the weld metal mechanical properties of quenched and tempered steels are dependent upon cooling rate which is presently indirectly controlled by specification of heat input.
Abstract: : It is known that the weld metal mechanical properties of quenched and tempered steels are dependent upon cooling rate, which is presently indirectly controlled by specification of heat input. A method to directly control weld metal cooling rate would result in more consistency in achieving required mechanical properties. In the present investigation the use of commercial infrared sensing equipment was explored as a means of real-time monitoring of weld metal cooling rate. Infrared equipment has a distinct advantage over other temperature detecting systems in that it requires no physical contact with the work, thus affording a minimum amount of interference with the welding process, and is therefore a potentially useful detector for an adaptive feedback welding control system based on cooling rate. It was found that infrared thermography appears to offer considerable promise for welding control by providing weld metal cooling rates which are: (1) reproducible, (2) sensitive to variations in welding conditions, and (3) relatable to cooling rates as measured by plunged thermocouples. (Author)
47 citations
TL;DR: In this article, a new radiometric method capable of reaching a better control of the volume of the tissue under investigation in microwave thermography is described, which is mainly used in biomedical applications.
Abstract: We describe a new radiometric method capable of reaching a better control of the volume of the tissue under investigation in microwave thermography (this technique is mainly used in biomedical applications). Our process is based on the fact that two (or several) probes with a volume under investigation in common are collecting thermal noise signals which are correlated.
35 citations
TL;DR: A low-cost heat-sensitive television camera has been evaluated for the thermographic estimation of burn depth in two short clinical trials and thermography correctly identified the extent of all deep burns.
24 citations
TL;DR: In this paper, a non-destructive inspection technique employing infrared (IR) thermography was developed; the inspection can be performed in a production environment before the expensive step of completing wire bonding to the case has occurred.
Abstract: A method for nondestructive inspection of the thermal transfer effectiveness of adhesive bonds between the substrate and package (case) in the production of hybrid microcircuits is described. Because this bond is a series element in the thermal path for removal of the power dissipated by the microcircuit, its effectiveness is crucial to maintaining relatively low component-operating temperatures. As is well known, this can be directly equated to increasing reliability. Because the bonding material is between two opaque surfaces, it cannot be visually inspected. This situation motivated the work described here, which yielded the following results. 1) A nondestructive inspection technique employing infrared (IR) thermography was developed; the inspection can be performed in a production environment before the expensive step of completing wire bonding to the case has occurred. 2) The ability of the technique to distinguish between good and bad thermal bonds was demonstrated using two specially prepared test hybrids. 3) An analysis of the test method for use in planning inspection tests and interpretation of the test results was developed. The results show that this thermal imaging inspection technique affords a method to improve the quality of hybrid thermal bonding.
15 citations
TL;DR: The results obtained by thermographic and schlieren methods have modified a number of ideas on temperature distribution and convective heat loss as mentioned in this paper, which can be demonstrated over the whole body with a detail that would be difficult to achieve with probe techniques.
Abstract: Publisher Summary Thermography produces detailed pattern of skin temperature, which seen to be much more complex than has been revealed by thermocouple and other techniques. However, it is perhaps comforting to those who have used thermocouple techniques that the mean skin temperatures measured by the two methods agree reasonably well. Nevertheless, regional skin temperatures measured by thermocouples and thermography may be very different. The pattern of temperature change in different activities or in different environments, as shown by thermography, would also be very difficult to predict or demonstrate without this technique. The results obtained by thermographic and schlieren methods have modified a number of ideas on temperature distribution and convective heat loss. The complex nature of skin temperature distribution and its variation with different environments and with exercise can be demonstrated over the whole body with a detail that would be difficult to achieve with probe techniques. The description of the convective boundary-layer flow given by the visualization of the moving air streams presents information that is largely different. The techniques described in the chapter are sensitive enough to provide visual demonstration of many of the thermal effects to which the body responds and which otherwise are difficult to describe adequately.
12 citations
TL;DR: In this paper, temperature measurements in fat-muscle phantoms using thermography and a minimally perturbing temperature probe were investigated, and the discrepancies between data taken with the thermographic camera versus the probe were measured.
Abstract: Temperature measurements in fat-muscle phantoms using thermography and a minimally perturbing temperature probe were investigated. Two microwave applicators (915- and 2450-MHz) were used to induce the heating in the phantom. Discrepancies between data taken with the thermographic camera versus the probe were measured. These discrepancies were shown to be primarily caused by a 40-s time delay in performing temperature measurements with the thermographic camera, which resulted in additional thermal diffusion in the phantom.
8 citations
TL;DR: Two new types of thermographic instruments sensitive to millimeter-wave electromagnetic radiation have been designed, constructed, and tested and are designed to contribute to the clinical detection of breast abnormalities with the specific aim of accurately and noninvasively detecting breast cancer.
Abstract: Two new types of thermographic instruments sensitive to millimeter‐wave electromagnetic radiation have been designed, constructed, and tested. These instruments utilize wavelengths that are three orders of magnitude longer and much more penetrating then those used in conventional infrared thermography. The instruments are capable of detecting apparent thermal variations as small as a fraction of a degree existing at tissue depths of several millimeters below the skin. By comparison, conventional IR thermographic units are limited to sampling radiation emitted only from the surface. The millimeter wave thermographic units are designed to contribute to the clinical detection of breast abnormalites with the specific aim of accurately and noninvasively detecting breast cancer.
7 citations
TL;DR: Thermography allows the performance of nephrotomies in an avascular plane with minimal bleeding and subsequent minimal renal parenchymal destruction.
7 citations
01 Jan 1981
TL;DR: In this article, aerial thermographic data interpretation, aerial infrared survey field evaluations for residential applications, and infrared thermography applications in relation to the Low-Cost Solar Array Program are considered.
Abstract: Thermography applications in industrial plants and utility systems are considered. Topics discussed include aerial thermographic data interpretation, aerial infrared survey field evaluations for residential applications, and infrared thermography applications in relation to the Low-Cost Solar Array Program. Also considered are new trends in infrared technology, and training and standards regarding thermography.
5 citations
TL;DR: Liquid-crystal thermography is a rapid, noninvasive, inexpensive method for determining the lateral extents of certain cutaneous malignancies but little help in outlining neoplasms of low cellular density like morpheaform basal-cell carcinomas.
Abstract: Liquid-crystal thermography is a rapid, noninvasive, inexpensive method for determining the lateral extents of certain cutaneous malignancies. This report describes the technique as it is applied to basal-cell carcinomas. Results indicate that it is useful for neoplasms of moderate to heavy cellular density but little help in outlining neoplasms of low cellular density like morpheaform basal-cell carcinomas.
4 citations
27 Jan 1981
TL;DR: In this article, the infrared thermal imaging system was found to be a more versatile tool for in-situ moisture detection because of its unique characteristics, and several thermographic examples of moisture detection in building walls were presented, which will aid the reader in the qualitative interpretation o1 thermograms 1or moisture problem.
Abstract: Visual examination is a reliable means of moisture detection in building walls after serious damaR'e has been done. Traditional spot measurement instruments are inexpedient devices for elusive moisture detection in heterogeneous materials. The infrared thermal imaging system was found t be a more versatile tool for in-situ moisture detection because of its unique characteristics. Several thermographic examples of moisture detection in. building walls are presented, which will aid the reader in the qualitative interpretation o1 therm.ograms 1or moisture problem.s.© (1981) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
01 Aug 1981
TL;DR: In this article, a method for energy conservation, the aerial thermography survey, is discussed, which locates sources of energy losses and wasteful energy management practices, and an operational map is presented for clear sky conditions.
Abstract: A method for energy conservation, the aerial thermography survey, is discussed. It locates sources of energy losses and wasteful energy management practices. An operational map is presented for clear sky conditions. The map outlines the key environmental conditions conductive to obtaining reliable aerial thermography. The map is developed from defined visual and heat loss discrimination criteria which are quantized based on flat roof heat transfer calculations.
01 Jan 1981
TL;DR: In this article, an infra-red camera with video isotherm readout is used to identify perturbations in uniform or linear thermal fields which may be caused by presence of flaws or damage such as matrix cracks, delaminations, blind side impact damage, and partial through holes.
Abstract: This paper describes ongoing research eHorts to evaluate thermographic teci1niques for locating flaws or damage in structural fiber composite laminates. An infra-red camera with video isotherm readout is used to identify perturbations in uniform or linear thermal fields which may be caused by presence of flaws or damage such as matrix cracks, delaminations, blind side impact damage, and partial through holes. This procedure has potential for rapid qualitative screening of large surface areas. Potential defective areas may then be analyzed by a more accurate (but more time consuming) method . Two techniques are discussed; externally applied thermal field (EATF) and stress-generated thermal field (SGTF). The EATF technique involves applying heat to a composite structure and observing theresulting transient thermal pattern. The SGTF technique requires stress cycling to create hot spots in regions of high stress concentrations adjacent to flaws or damage sites.
TL;DR: The application of the Kolmogorov-Smirnov, non-parametric statistical tests to image processing is presented and advantages of real-time operation are discussed.
Abstract: The application of the Kolmogorov-Smirnov, non-parametric statistical tests to image processing is presented. Examples are shown for image segmentation and target detection in a series of thermal infrared (8 to 14m) images. Advantages of real-time operation are discussed.
01 Jan 1981
TL;DR: Thermography can be used to examine the long-term effect of drug therapy because the basic pattern of the thermographie picture of the skin surface remains constant, and these effects can be demonstrated by thermography (AGA-thermovision) which shows the infrared radiation from theskin surface.
Abstract: Distinct psoriatic lesions display a small increase in skin temperature of about 0.5–1.0 °C compared to the surrounding not affected skin. Conventional therapy of psoriasis with dithranol (0.5–1%) or UVB, including photochemotherapy, leads to a remarkable increase anywhere between 1 and 4 °C. These effects can be demonstrated by thermography (AGA-thermovision) which shows the infrared radiation from the skin surface. Thermography can be used to examine the long-term effect of drug therapy because the basic pattern of the thermographie picture of the skin surface remains constant (1–3).
15 Jun 1981
TL;DR: In this paper, temperature measurements in fat-muscle phantoms using thermography and a non-perturbing temperature probe were investigated, and the probe data indicate significant thermography errors.
Abstract: In support of the BRH proposed microwave diathermy standard, temperature measurements in fat-muscle phantoms using thermography and a non-perturbing temperature probe were investigated. These probe data indicate significant thermography errors.
27 Jan 1981
TL;DR: In this article, the basic physical laws that make infrared thermal sensing instruments work, and explains how they are used to detect and measure heat loss in structures, are described and discussed.
Abstract: Everything above absolute zero radiates infrared energy in proportion to its surface temperature. When the objects are hot enough they radiate visibly and our eyes can see them glow. As they cool their radiation becomes invisible to the eye. We then can use infrared thermal sensors and scanners to measure their self-emitted infrared radiation and relate it to surface temperature. When the inside and outside of a structure are at different temperatures thermal energy flows through the walls and ceilings. The better the insulation, the less energy flow and the more is conserved. Changes in wall and ceiling surface temperatures are an indication of the thermal energy loss. This paper introduces the basic physical laws that make infrared thermal sensing instruments work, and explains how they are used to detect and measure heat loss in structures.
27 Jan 1981
TL;DR: In this article, the authors present a tutorial introduction to the methods used in acquiring and interpreting ground-based thermographic data for the detection of building heat losses and the major heat loss mechanisms in buildings which produce the thermal anomalies detectable by infrared scanning systems.
Abstract: This paper presents a tutorial introduction to the methods used in acquiring and interpreting ground-based thermographic data. It summarizes basic principles used in the anal-ysis of groundbased thermographic data for the detection of building heat losses. The major heat loss mechanisms in buildings which produce the thermal anomalies detectable by infrared scanning systems are described. The paper emphasizes that the analysis of thermographic data is an exercise in pattern recognition and, as such, gives results of a qualitative nature. The thermal patterns of several classes of building defects are presented. Methods for determining from thermographic inspection voids in insulated walls, areas with partial insulation, defective ceiling insulation, fissures and shrinkage in insulation, heat loss around doors and windows, air leakage at wall and floor joints, attic bypasses and thermal bridges, air penetration into interior cavities, and moisture damaged insulation are illustrated by examples of thermograms showing each class of defect. The difficulty of performing thermographic inspection under nonstandard conditions when the building is subjected to a small temperature difference across the building envelope, solar loading on the inspected surface, or transient environmental conditions is discussed. The relative merit of interior and exterior surveys and the effect of environmental conditions, thermal reflections and variation in the surface properties on the interpretation of thermograms are analyzed.
Journal Article•
TL;DR: Plate thermography proved to be suitable in the lower leg for the detection of smaller differences in temperature and seems to be superior to infrared thermovision from an economic point of view.
Abstract: With the help of thermographic plates developed by the department of physical chemistry of the Martin Luther University Halle it was possible to detect in 50 patients 158 insufficient venae perforantes, which were found by x-ray examination, from total of 175 The causes for 17 insufficient venae perforantes not diagnosed thermographically were inadequate application of the plates in ulcus cruris, the existence of a pair of perforating veins and functionally unimportant bypasses Plate thermography proved to be suitable in the lower leg for the detection of smaller differences in temperature Evaluating these results in comparison to the literature references there was no difference between our method and the infrared thermovision From an economic point of view plate thermography seems to be superior to infrared thermovision In contrast to this, plate thermography has the disadvantage of a longer time for examination and problems in documentation and registration of the results