An Overview of Hydrogen Safety Sensors and Requirements

There exists an international commitment to increase the utilization of hydrogen as a clean and renewable alternative to carbon-based fuels. The availability of hydrogen safety sensors is critical to assure the safe deployment of hydrogen systems. Already, the use of hydrogen safety sensors is required for the indoor fueling of fuel cell powered forklifts (e.g., NFPA 52, Vehicular Fuel Systems Code [1]). Additional Codes and Standards specific to hydrogen detectors are being developed [2, 3], which when adopted will impose mandatory analytical performance metrics. There are a large number of commercially available hydrogen safety sensors. Because end-users have a broad range of sensor options for their specific applications, the final selection of an appropriate sensor technology can be complicated. Facility engineers and other end-users are expected to select the optimal sensor technology choice. However, some sensor technologies may not be a good fit for a given application. Informed decisions require an understanding of the general analytical performance specifications that can be expected by a given sensor technology. Although there are a large number of commercial sensors, most can be classified into relatively few specific sensor types (e.g., electrochemical, metal oxide, catalytic bead and others). Performance metrics of commercial sensors produced on a specific platform may vary between manufacturers, but to a significant degree a specific platform has characteristic analytical trends, advantages, and limitations. Knowledge of these trends facilitates the selection of the optimal technology for a specific application (i.e., indoor vs. outdoor environments). An understanding of the various sensor options and their general analytical performance specifications would be invaluable in guiding the selection of the most appropriate technology for the designated application.