As the hydrogen economy grows, so does the need for fast, reliable gas leak detection.
Hydrogen is widely regarded as one of the most promising fuels in the transition to clean energy, but it is also one of the most demanding to handle safely. It is colourless, odourless, and has one of the widest flammability ranges of any gas, igniting at concentrations from just 4% up to 77% in air, with an explosive range between 18% and 59%. The energy required to ignite it is extremely low and can come from something as simple as a static discharge. A reliable gas leak sensor is not a nice to have in hydrogen systems; it is a fundamental safety requirement.
Why Hydrogen Leak Detection Is So Difficult
Conventional gas detection methods often struggle with hydrogen because of its physical properties. It is the lightest element on the periodic table, which means it disperses rapidly and rises quickly, behaviour that can make leaks difficult to localise using detectors positioned in the wrong place or with insufficient sensitivity. At the same time, false alarms triggered by ambient conditions or cross sensitivity to other gases can undermine confidence in a detection system, leading operators to ignore genuine warnings.
This combination, rapid dispersal, wide flammability range, and low ignition energy, means that a gas leak sensor for hydrogen applications needs to be both highly sensitive and highly selective, responding accurately to hydrogen while remaining stable in the presence of other volatile compounds.
How H Guard Addresses the Challenge
L'équipe de Metis Engineering H Garde sensor is purpose built for exactly this problem. Derived from our proven Cell Guard platform, H Guard detects hydrogen concentrations across a 0 to 20% range, comfortably below the 4% lower flammability limit, giving operators a meaningful early warning window before conditions become dangerous.
Beyond hydrogen, H Guard also measures absolute pressure, air temperature, volatile organic compounds, absolute air water content, relative humidity, and dew point temperature, giving a fuller picture of the environment around a hydrogen system rather than a single binary alarm trigger. An optional accelerometer, measuring shock load and duration up to plus or minus 24G, can also be added for applications where mechanical impact is a relevant safety consideration.
Detecting More Than Just Leaks
One of H Guard’s more distinctive capabilities is its sensitivity to hydrogen generated through electrolysis inside sealed battery packs or fuel cells. Where water ingress occurs in a compromised enclosure, the resulting electrolysis can produce hydrogen as a byproduct, an early indicator of degradation or failure that would otherwise go unnoticed until far more serious damage had occurred. For battery and fuel cell manufacturers, this gives H Guard a dual role: hydrogen leak sensor and early warning indicator for pack integrity.
Built for the Full Hydrogen Lifecycle
H Guard is designed to operate across the breadth of hydrogen applications, from production and storage through to distribution, mobility, and end use. This includes hydrogen storage tanks and distribution networks, hydrogen combustion engines and fuel cell electric vehicles, electrolysers and other production equipment, and hydrogen powered aviation, marine, and industrial installations.
Robust performance in harsh, real world environments was a core design requirement. H Guard operates across an extended temperature range from minus 40°C to plus 85°C, resists oil poisoning in high VOC environments, and draws under 1mA in standby mode, allowing continuous monitoring without placing undue strain on system power budgets. Readings are available instantaneously upon startup, with no warm up period required, a meaningful advantage in safety critical environments where every second counts.
Designed for Easy Integration
As with the rest of the Metis sensor range, H Guard communicates over CAN bus with a configurable speed and address, supplied alongside a CAN DBC file for straightforward integration into existing control architecture. A compact, automotive rated 5-pin Molex Nano-Fit power connector keeps installation simple even in space constrained systems, including those using compressed hydrogen.
The unit has been tested to recognised automotive standards, including ISO 7637-2:2011, ISO 16750-2:2012, and ISO 16750-4:2010, with ATEX rating certification currently in progress.
A Smarter Approach to Hydrogen Safety
As hydrogen infrastructure scales, from production facilities and refuelling stations to hydrogen powered vessels and aircraft, the systems monitoring that infrastructure need to be just as forward thinking as the technology itself. A gas leak sensor that can detect trace concentrations early, operate reliably in harsh conditions, and integrate cleanly into existing control systems gives engineers the confidence to build with hydrogen at scale.
Speak to Our Team
If you are developing a hydrogen system and want to discuss how H Guard could fit into your safety architecture, contact our engineering team or view the full H Guard product page for technical specifications.
