Many electronic applications present in our everyday life would not be possible without sensors. Without their ability to measure or control physical quantities, many electronic devices would remain as simple laboratory curiosities. This book is unique in its treatment of both signal conditioning and sensors. It has established itself as a successful professional book and also as a textbook in advanced graduate courses. The second edition is updated to take account of new developments. The following are the important changes: It will include several sensors not included in the first edition, such as resistive gas sensors, magnetostrictive sensors, SQUIDS, flux gate magnetometers, Wiegand sensors, position-sensitive detectors and semiconductor-junction nuclear radiation detectors. A new section on materials for sensors and a section on microsensor technologies. Chapter 8 has been expanded by adding sections on variable oscillators. In summary, the second edition will cover both macrosensors and microsensors from the same point of view as the first edition, which was that of the electronic engineer who must understand how a given sensor works and its advantages and shortcomings in order to apply it and design or specify a suitable signal conditioner. In order to aid the use of the book as a textbook, several additional worked examples and additional problems will be included.