Hydrogen is a highly combustible gas that can pose a severe risk in industrial settings and in fuel cells. It is critical to detect leaks in order to prevent fires, explosions and asphyxiation. Several different types of hydrogen detectors are available that use either electrochemical, catalytic combustion, metal-oxide semiconductor or thermal conductivity sensing technologies. It is important to choose the right sensor based on the conditions and limitations of the particular application, and the type of environment where it will be used. Resource

Hydrogen in Refinery Processes

The production of hydrogen is widely utilized in oil refineries for processes such as hydrocracking, which reduces heavy petroleum residues to lower molecular weight constituents. Hydrogen is also used in the synthesis of ammonia (NH3) and nitrogen-based fertilizers. This creates a high potential for hydrogen leaks, especially in confined spaces where it can accumulate to dangerous concentrations and trigger explosions or asphyxiation. Wall-mounted hydrogen detectors as well as personal protection handheld units can be installed in these locations to help monitor for possible leaks and provide early warning to staff.

Detecting Hydrogen Leaks in Industrial Settings: Applications and Solutions

Pellistor hydrogen sensors (also known as catalytic combustible gas sensors) measure the concentration of any flammable gases in the air. The sensor consists of two beads, one which is passivated without any catalyst and the other coated with a catalyst to facilitate the reaction with hydrogen molecules. When a flammable gas is present, the catalyst bead will oxidize resulting in a change in resistance of the Wheatstone bridge circuit which then changes the output voltage value Vout.