Infrared Thermography: Recent Advances and Future Trends

The book is organised in two main parts: Part I and Part II and into several chapters. The Part I includes two chapters. The first one, by the Editor, deals with basic theory, which is described following the historical steps by eminent scientists, from Herschel, to Nobili, Melloni, Stefan, Boltzmann, Planck and others. The radiation mechanisms with the most important parameters, which play a key role in acquisition and interpretation of thermal images are recalled and discussed. A section is devoted to detectors used for infrared technology. The main steps in detectors development following the technological progress are also drawn. The second chapter is by Roberto Rinaldi of the Infrared Training Center (ITC) by Flir Systems in Milan (Italy). This chapter is concerned with an overview of infrared imaging devices from the first prototype developed in 1958 to the multitude of models, which are today available. The historical evolution of the infrared technology is traced within the key features of each model. In particular, some basic characteristics and performance are described which may help the reader in the choice of the most appropriate device for the specific application. Part II is subdivided into four sections and many chapters. The first section regards applications to medicine (Chap. 1) and veterinary (Chap. 2). The study of the temperature of the human body has been associated with health as far back as the 1st century BC, when Hypocrites, (the father of medicine), used the sense of touch to skin surface temperature anomalies and to determine the health of his patients. Still today, monitoring the body temperature variation, aides in both diagnosis and treatment planning. Chapter one was prepared by Boris G. Vainer of the Institute of Semiconductor Physics of the Russian Academy of Sciences. This chapter reports on the IRT’s state of art in medicine with methodological approaches and a variety of applications such as in the diagnosis of breast cancer, in ophthalmologic surgery, in cardiovascular surgery, in the visualization of ischemic tissues and in many others. Chapter two presents application and use of infrared thermography in farm animals and veterinary medicine. This chapter was supplied by Petr Kunc and Ivana Knizkova of the Institute of Animal Science - University of Prague (The Czech Republic). The addressed areas include reproduction, thermoregulation, animal welfare and the milking process. The application of IRT to veterinary medicine is particularly useful to predict inflammation since, contrary to human beings, animals cannot reveal any symptom before the illness has become important. Section two includes a chapter on the use of Infrared thermography in foodstuff conservation by Klaus Gottschalk of the Leibniz-Institut für Agrartechnik Potsdam (Germany). It is shown the usefulness of IRT to control the conservation conditions of fruits and vegetables. The main advantage of using an infrared device lies in the possibility to control and improve the climate, which is essential in prolonging the shelf life of crops. Section three regards applications of IRT to industrial engineering. The first chapter, prepared by Giovanni M. Carlomagno of the Department of Aerospace Engineering - University of Naples Federico II (Italy), is an overview on IRT to thermo-fluid-dynamics. After recalling the first historical attempts in measuring heat transfer coefficients, this chapter describes the most useful heat flux sensors, supplies information about thermal restoration of data and shows several examples of convective heat transfer measurements in complex fluid flows, ranging from natural convection to hypersonic regime. The attention of chapter two is focused on the application of IRT to combustion. This contribution is by Christophe Allouis and Rocco Pagliara of the Combustion Institute CNR in Naples (Italy). It is demonstrated the usefulness of an infrared imaging system for understanding fluid-dynamics phenomena associated with combustion processes in turbine burners. The third chapter by Ralph A. Rotolante of Vicon Infrared in Boxborough, MA (USA) regards the use of IRT for nondestructive inspection purposes. The main pulse and lockin techniques are described with some application examples including also the inspection of real aircraft parts. Indeed, a remote imaging system offers many advantages over other methodologies since it is fast and two-dimensional with safeguard of the part integrity. Section four is concerned with the application of IRT in architecture and civil engineering. This is a relevant topic for infrared thermography applications after Building Regulation (2007) for Conservation of Fuel and Energy. A chapter by Ermanno Grinzato of CNR-ITC in Padua (Italy) reports some examples of structural analysis aided by IR thermography. In particular, it is stressed the impressive help, which is given to the comfort monitoring by the distributed temperature map measured by an infrared device. The attention goes also to the possibility, using a novel method, to “see” the environmental main quantities as air temperature, relative humidity and velocity, obtained from thermographic readings. Besides those herein described, an infrared imaging system can be advantageously used for many other applications. Infrared thermography is an excellent condition monitoring tool to assist in the reduction of maintenance costs on mechanical equipment. One of the biggest problems in mechanical systems is heat generated by friction, cooling degradation, material loss or blockages. The infrared technique allows for the monitoring of temperatures and thermal patterns, on a wide variety of equipments including pumps, motors, bearings, pulleys, fans, drives, conveyors etc, and while the equipment is online and running under full load. Information acquired from thermographic images enable a company to predict equipment failure and to plan corrective actions before a costly shutdown, equipment damage, or personal injury occurs. What it is more, the inspection can be performed far away from any dangerous condition without additional costs in terms of workers health care. However, it has to be pointed out that infrared thermography is still not completely exploited. It could be employed in a lot of other novel applications; it is only a matter of fantasy and skill!