The fourth volume titled 'Sensors and Applications in Measuring and Automation Control Systems' contains twenty four chapters with sensor related state-of-the-art reviews and descriptions of latest advances in sensor related area written by 81 authors from academia and industry from 5 continents and 20 countries: Australia, Austria, Brazil, Finland, France, Japan, India, Iraq, Italia, M xico, Morocco, Portugal, Senegal, Serbia, South Africa, South Korea, Spain, UK, Ukraine and USA. Coverage includes current developments in physical sensors and transducers, chemical sensors, biosensors, sensing materials, signal conditioning, energy harvesters and sensor networks.