Scientia Publishing House – Sapientia Hungarian University of Transylvania

Érzékelők és mérőhálózatok [Sensors and Measuring Networks]

The book is a university textbook for bachelor’s and master’s students in the fields of mechatronics, machine-building technology, automation, computers and telecommunications at Sapientia Hungarian University of Transylvania, but is also useful to other specialists interested in the subject. After the first volume of the authors (Székely, Gy.; Túrós, L.Zs.: Electrical, Electronic and Virtual Measurements, Ed. Scientia, Cluj Napoca, 2020), in which the means and methods of electrical-electronic measurement are presented, this volume extends the treatment of measurements of any quantity by electrical-electronic means. The authors also meet the changes in the curriculum of Mechatronics, in which the discipline of Sensors and Sensory Systems appears in the category of measurements.

Due to the difficulty of a unified classification of the sensors either according to the operating principles or according to the measured quantities, a combined approach was chosen. The book is structured in three parts, in a total of 18 chapters. The first part presents the sensors in terms of operating principles, the second part addresses the sensors in terms of measured non-electrical quantities, and the third part deals with techniques for integrating sensors and data processing circuits, as well as wired and wireless networks/interfaces often used in the interconnection of sensory systems. In the first part of the book (six chapters), after the characterization and classification of the sensors, general principles of sensor operation are presented. After analysing the sensors in the categorization of passive (parametric: resistive, inductive, capacitive) and active (generators: thermoelectric, piezoelectric, photoelectric), the analysis of some classes of techniques follows, which are often used in measuring non-electric quantities with sensors. This presents ultrasound and electromagnetic waves (microwaves, infrared radiation, lasers), and corpuscular and nuclear electromagnetic radiation. The sixth chapter addresses the class of incremental and absolute code digital sensors for measuring movement and position.

The second part of the paper (eight chapters) deals with means and methods for measuring classes of non-electric quantities, based on the sensors presented in the first part of the book, and on the development of principles specific to measured quantities, which, according to the authors, are of interest to the students of the mentioned study programs. At the beginning, the dimensions of speed, acceleration and mechanical vibration, force and mechanical torque, gyroscopes (for angular velocity), pressure and flow are analysed. These chapters aim to cover as wide and topical an area as possible of the multiple aspects of the measurements of those quantities. For example, the chapter on force measurement presents means and methods of force measurement, electronic scales and tactile sensors, and in the mechanical torque measurement part classical measurement methods, as well as brake benches used to test engines. The gyroscopes also address the classic rotating gyroscope, which uses the precession force, but also the oscillating gyroscopes, using the Coriolis force, already in forms integrated by MEMS technologies, from where it is a direct path to IMU sensors.

The last three chapters of the second part discuss wider areas of phenomena and quantities, such as environmental parameters, acoustic noise and chemical quantities, the latter being analysed more generally, given the extraordinary multitude of categories of chemical quantities, with use in industry, medicine, biochemistry, environment, etc. The third part of the book begins with a chapter, which analyses MEMS and NEMS technologies for the development of sensors and actuators at the microscopic level, with a direct consequence of the development of intelligent sensors.

It is obvious that modern, digital and intelligent sensors must use the major advantages of data processing and storage systems (computers, microprocessors, microcontrollers, computer networks, Internet), which is why the last three chapters are dedicated to interfaces and measurement networks. These chapters briefly present, but with applicability, the I2C and SPI wireless interfaces, Bluetooth and RFID wireless, concluding with structures and strategies for configuring WSN (wireless sensor networks), which integrate organically into the world of Internet of Things. The book is made in remarkable graphic conditions with many figures, necessary to understand the very wide area of principles, which requires serious knowledge of physics and chemistry. A general approach in this book is to present a brief theoretical summary of each new principle or method for sensors or measurement classes, followed by the extensive development of sensors and methods.