Experimental Design for Estimating Electro-Thermophysical Properties of a Thermopile Thermal Radiation Detector

As the Earth's atmosphere evolves due to human activity, today's modern industrial society relies significantly on the scientific community to foresee possible atmospheric complications such as the celebrated greenhouse effect. Scientists, in turn, rely on accurate measurements of the Earth Radiation Budget (ERB) in order to quantify changes in the atmosphere. The Thermal Radiation Group (TRG), a laboratory in the Department of the edge of technology designing and modeling ERB instruments. TRG is currently developing a new generation of thermoelectric detectors for ERB applications. These detectors consist of an array of thermocouple junction pairs that are based on a new thermopile technology using materials whose electro-thermophysical properties are not completely characterized. The objective of this investigation is to design experiments aimed at determining the electro-thermophysical properties of the detector materials. These properties are the thermal conductivity and diffusivity of the materials and the Seebeck coefficient of the thermocouple junctions. Knowledge of these properties will provide fundamental information needed for the development of optimally designed detectors that rigorously meet required design specifications. iii Acknowledgments I would like to express my deepest gratitude to all the people who in one way or another contributed to the completion of this work. • To Dr. Robert Mahan, my thesis advisor, for motivating me to enroll at Virginia Tech, for his guidance and recommendations. advisory committee and for their suggestions and time devoted to my thesis. • To the members of the Thermal Radiation Group, my lab partners, for their friendship and support during my graduate studies. • To my wife for her continuous encouragement, help and patience. • To my family for their support and for sharing with me the satisfaction of reaching this goal. Table 1.1 Nominal properties of materials used in thermal radiation detector [Weckmann, Table 4.2 Relative difference between the nominal value and the sample mean of the estimated values of k 3 and k 6 during simulated experiments (uncertainty in temperature measurements = ± 1.0 percent) , Table 4.3 Relative difference between the nominal value and the sample mean of the estimated values of α j , α 3 and α 6 during simulated experiments (uncertainty in temperature measurements = ± 1.0 percent), Table 4.4 Relative difference between the nominal value and the sample mean of the estimated values of α ZnSb Pt − during simulated experiments (uncertainty in temperature measurements = ± 1.0 percent), Figure 4.6 Relative difference between …