How Mobile Gas Sensor Trajectories Govern Hydrogen Leak Detection: A Safety Gap in Manual Leak Inspection of Hydrogen System Components
2026-07-10 • Robotics
Robotics
AI summaryⓘ
The authors studied how following different paths with gas sniffers affects the ability to detect hydrogen leaks in small pipes. They found that moving the sensor too fast or along straight lines often misses leaks, which is risky for safety. Instead, moving around the pipe in specific patterns works much better for finding leaks. They created rules based on pipe shapes to guide how to scan and made software to help plan these better paths automatically. Their work points out that current manual methods can be unsafe and need improvement.
hydrogen leak detectiontracer gas sniffingelectrolyzerrobotic guidancepipe fittingsscanning velocityfalse negativesgas dispersion3D modelingsafety standards
Authors
Christian Masuhr, Arne Wendt, Thorsten Schüppstuhl
Abstract
The integrity of hydrogen infrastructure relies on reliable leak detection, performed almost exclusively via manual tracer gas sniffing in electrolyzer manufacturing. Although mandated by standards, the lack of spatial probe guidance instructions leaves detection reliability entirely to operator execution, further compromised by sensor signal delays. This study quantifies how sniffer trajectory kinematics affect detection reliability at small-scale pipes and fittings, a near-field regime largely neglected by macroscopic dispersion research. Using a robotically guided test bench to eliminate operator variability, static concentration fields and dynamic trajectory passes were acquired across representative geometries under standardized leak rates (5 vol% hydrogen in nitrogen) and varying scanning velocities. Results demonstrate that scanning velocity and spatial probe orientation strongly dictate detectability. Conventional linear trajectories frequently miss leaks under dynamic conditions, causing severe false negatives. Conversely, geometry-specific routing, such as circumferential plunging paths around sealing points, maintains a high safety margin. From these observations, geometry-specific routing rules and a reduction-factor model for dynamic signal loss are derived. The findings reveal that current standard operating procedures pose a tangible safety risk. To operationalize these rules, a proof-of-concept software pipeline is presented, generating validated trajectories directly from 3D models for visualization in assistance systems.