ABSTRACT
Due to the unique physical and chemical properties of hydrogen, hydrogen-based applications require rigorous safety precautions in comparison to other industrial gases. Since the use of odorants in many hydrogen applications is not possible, dedicated detection devices or sensors are essential to warn of the presence of unwanted hydrogen leaks. Hydrogen sensors play an essential role in ensuring the safety of hydrogen-based applications. As such, sensors boost end user confidence and therefore facilitate the safe use and commercialization of hydrogen as an alternative fuel. This chapter reviews the available commercial hydrogen-sensing technologies and their operating principles. There are several different types of hydrogen sensors and the most common commercial types are catalytic, electrochemical, thermal conductivity, semiconductive metal–oxide, and metal–oxide–semiconductor sensors. The chapter discusses the performance characteristics of these sensor types, such as measuring range, sensitivity, selectivity, and response time. Available emergent technologies and their impact on improved hydrogen gas sensing are also presented.
