Thomas Hübert is head of the laboratory and working group on chemical sensor technology and sol-gel chemistry at the Federal Institute for Materials Research and Testing (BAM) in Berlin, Germany. Dr. Hübert participates in national and international standardization activities, including the ISO working group for hydrogen detection, and is the author/coauthor of more than 130 scientific publications. His research interests include the development, testing, calibration, and certification of gas and humidity sensors especially for automotive applications. Lois Boon-Brett led the hydrogen safety sensor performance testing task at the European Commission’s Joint Research Centre-Institute for Energy and Transport (JRC-IET) in Petten, The Netherlands. In this context, Dr. Boon-Brett was a member of the ISO and IEC sensor working groups. Her research interests include hydrogen safety sensor performance testing and technology validation. She currently leads the electric vehicle battery-testing group at the JRC-IET. William Buttner is a senior scientist in the Transportation and Hydrogen Systems Center at the National Renewable Energy Laboratory (NREL) in Golden, Colorado, where he manages the Hydrogen Sensor Laboratory. He is active on a variety of standards development organizations that pertain to the safe use of hydrogen, including ISO, ASTM, SAE, and UL. Dr. Buttner has written more than 100 publications on chemical sensors and sensor-based methods for on-site chemical analyses. His research interests include chemical and physical sensor technology, field analytical chemistry, and electrochemical processes.