Sensors Thermal Sensors

This book describes the analysis and design of precision temperature sensors in CMOS IC technology, focusing on so-called smart temperature sensors, which provide a digital output signal that can be readily interpreted by a computer. The text shows how temperature characteristics can be used to obtain an accurate digital temperature reading. The book ends with a detailed description of three prototypes, one of which achieves the best performance reported to date.

The problems involved in designing optimal infrared (IR) measuring systems under given conditions are commensurately complex. The optical set-up and radiation conditions, the interaction between sensor and irradiation and the sensor itself, determine the operation of the sensor system. Simple calculations for solving these problems without any understanding of the causal relationships are not possible. Thermal Infrared Sensors offers a concise explanation of the basic physical and photometric fundamentals needed for the consideration of these interactions. It depicts the basics of thermal IR sensor systems and explains the manifold causal relationships between the most important effects and influences, describing the relationships between sensor parameters such as thermal and special resolution, and application conditions. This book covers: various types of thermal sensors, like thermoelectric sensor, pyroelectric sensors, microbolometers, micro-Golay cells and bimorphous sensors; basic applications for thermal sensors; noise - a limiting factor for thermal resolution and detectivity - including an outline of the mathematics and noise sources in thermal infrared sensors; the properties of IR sensor systems in conjunction with the measurement environment and application conditions; 60 examples showing calculations of real problems with real numbers, as they occur in many practical applications. This is an essential reference for practicing design and optical engineers and users of infrared sensors and infrared cameras. With this book they will be able to transform the demonstrated solutions to their own problems, find ways to match their commercial IR sensors and cameras to their measurement conditions, and to tailor and optimise sensors and set-ups to particular IR measurement problems. The basic knowledge outlined in this book will give advanced undergraduate and graduate students a thorough grounding in this technology.

Thermal Sensors is intended as a comprehensive and accessible reference for designers and users of thermal sensors. Many different physical quantities can be converted easily and accurately into temperature differences using thermal techniques. These temperature differences can be detected with temperature and temperature-difference sensors. In a thermal sensor the thermal converter and the temperature sensor are combined in a single accurate device. This book gives an overview and deals with the design aspects of thermal and temperature sensors, with an emphasis on sensors based on silicon technology. The temperature sensors described are based on the use of various types of sensitive elements, such as platinum resistors, thermistors and special integrated circuits. The thermal sensors described include flow, conductivity, infrared, vacuum, humidity and calorimetric sensors, and ac-dc converters, thus providing a comprehensive overview of all thermal sensors, with practical examples of each type.

This book provides a comprehensive overview of the state of the art in the field of thermal infrared remote sensing. Temperature is one of the most important physical environmental variables monitored by earth observing remote sensing systems. Temperature ranges define the boundaries of habitats on our planet. Thermal hazards endanger our resources and well-being. In this book renowned international experts have contributed chapters on currently available thermal sensors as well as innovative plans for future missions. Further chapters discuss the underlying physics and image processing techniques for analyzing thermal data. Ground-breaking chapters on applications present a wide variety of case studies leading to a deepened understanding of land and sea surface temperature dynamics, urban heat island effects, forest fires, volcanic eruption precursors, underground coal fires, geothermal systems, soil moisture variability, and temperature-based mineral discrimination. ‘Thermal Infrared Remote Sensing: Sensors, Methods, Applications’ is unique because of the large field it spans, the potentials it reveals, and the detail it provides. This book is an indispensable volume for scientists, lecturers, and decision makers interested in thermal infrared technology, methods, and applications.

This book describes the design and theory of high-accuracy smart temperature sensors in CMOS technology. The book's major triumph is the realization of a smart temperature sensor of such high accuracy that it can be applied without any form of calibration. In addition, the authors provide the reader with an elaborate overview of dynamic offset-cancellation techniques and CMOS bandgap references, which are the basic techniques and building blocks that determine the overall accuracy of CMOS smart temperature sensors. The book's concluding chapters focus on realizations where other aspects like ultra low-design and remote temperature sensing are discussed. High-Accuracy CMOS Smart Temperature Sensors is essential reading for anybody with an academic or professional interest in semiconductor design.

This book is a comprehensive guide to both the fundamentals of thermal sensors and their advanced functions. Key topics include sensor materials, CMOS-compatible sensors, measurement capabilities, thermal management and manufacturing processes. The introductory chapter covers the basic principles of thermal sensors from the essentials of heat transfer to smart wireless sensors. Later chapters illustrate the wide range of thermal sensor uses, from microprocessor thermal sensing to energy converter applications. Modeling and simulation techniques are used to explain the future direction of the field. Designed for researchers and practitioners working with wireless sensors and thermal management, Thermal Sensors: Principles and Applications for Semiconductor Industries is a valuable reference to the benefits and challenges these sensors offer. Advanced-level students studying mechanical or electrical engineering and networks will also find the content useful.

FROM THE AUTHORS' PREFACE Sensors operating on interferometric principles and mounted inside optical fibers have recently been considered for measuring strain and temperature. Indeed, such sensors have successfully been employed for measuring pressure or temperature in fluids. Fiber optics sensors are especially adept for such measurements because sensors immersed in fluids can easily be calibrated by tests. Unfortunately, the use of fiber optic sensors inside solids is not as straightforward. Owing to the complex interactions between the sensor and the surrounding material, the relationship between the sensor output and the parameters of interest, namely the strain and temperature inside the material, cannot be determined by simple tests. And without the appropriate relationships, fiber optic sensors do not provide meaningful information. In general, the relationship providing the bridge between the sensor output and the engineering values of strain and temperature must be established via analytical models. The major aim of this book is to present such models for extrinsic and intrinsic Fabry-Perot sensors and for Bragg grating sensors embedded in or mounted on the surface of isotropic or anisotropic solids or immersed in fluids. The scope of the book is limited to the theory of fiber optic strain and temperature sensors. Accordingly, we have taken as our starting point the demodulated sensor signals. The hardware needed to produce these signals is not discussed. It is presumed that the reader is familiar with and has access to the sensor, light source, light detector and demodulator required for generating signals which can then be analyzed and interpreted by the methods presented in the book. The problem necessitates complex analytical developments. To assist the reader, the significant results are summarized in tables, and numerical examples are given illustrating the calculation procedures.

This book describes the design and implementation of energy-efficient smart (digital output) temperature sensors in CMOS technology. To accomplish this, a new readout topology, namely the zoom-ADC, is presented. It combines a coarse SAR-ADC with a fine Sigma-Delta (SD) ADC. The digital result obtained from the coarse ADC is used to set the reference levels of the SD-ADC, thereby zooming its full-scale range into a small region around the input signal. This technique considerably reduces the SD-ADC’s full-scale range, and notably relaxes the number of clock cycles needed for a given resolution, as well as the DC-gain and swing of the loop-filter. Both conversion time and power-efficiency can be improved, which results in a substantial improvement in energy-efficiency. Two BJT-based sensor prototypes based on 1st-order and 2nd-order zoom-ADCs are presented. They both achieve inaccuracies of less than ±0.2°C over the military temperature range (-55°C to 125°C). A prototype capable of sensing temperatures up to 200°C is also presented. As an alternative to BJTs, sensors based on dynamic threshold MOSTs (DTMOSTs) are also presented. It is shown that DTMOSTs are capable of achieving low inaccuracy (±0.4°C over the military temperature range) as well as sub-1V operation, making them well suited for use in modern CMOS processes.

Sensors and measurement systems is an introduction to microsensors for engineering students in the final undergraduate or early graduate level, technicians who wants to know more about the systems they are using, and anybody curious enough to know what microsystems and microsensors can do. The book discusses five families of sensors: - Thermal sensors - Force and pressure sensors- Inertial sensors - Magnetic field sensors- Flow sensorsFor each sensor, theoretical, technology and application aspects are examined. The sensor function is modelled to understand sensitivity, resolution and noise. We ask ourselves: What do we want to measure? What are possible applications? How are the sensor chips made in the cleanroom? How are they mounted and integrated in a system?After reading this book, you should be able to:- Understand important thermal, mechanical, inertial and magnetic sensors- Work with characterization parameters for sensors- Choose sensors for a given application and apply them- Understand micromachining technologies for sensors

Sensors and actuators are used daily in countless applications to ensure more accurate and reliable workflows and safer environments. Many students and young engineers with engineering and science backgrounds often come prepared with circuits and programming skills but have little knowledge of sensors and sensing strategies and their interfacing.