SENSISTOR, represented by Technical & Scientific , has developed a technology for making rugged, compact and portable detectors for hydrogen, which are highly selective.
The sensor is located at the tip of a relatively cheap hand held "wand", avoiding the need for vacuum pumps which can draw in dust and water.
The technology is already widely used for tracing leaks in underground cables, measuring the gas as it permeates its way to the surface.
A similar technique allows leak tracing in water pipelines, tanks, silos, pressure vessels and shipping containers.
Certification of underground petrol tanks is emerging as a major application.
Hydrogen is the ideal gas for detecting and finding leakage. It is present at a level of only 0.5% in the atmosphere, so even the tiniest leaks can be readily detected.
Its small molecular size allows it to pass more rapidly through a hole, and its diatomic molecule avoids the stickiness associated with inert gases such as Helium.
Mixtures of 5% hydrogen in nitrogen are not only non-flammable, they are used as a shielding gas for arc welding, and this volume usage makes the tracer mixture much less expensive than the alternatives.