Hydrogen sensor

A hydrogen micro- sensor is a small device that detects the presence of hydrogen. They are used to detect leaks.

Key Features

There are four main features that should satisfy a hydrogen sensor:

Reliability: easy nachzuprüfende functionality
Resolution: Detection of 0.5% or less hydrogen in the air, reaction time <1 second
Life: At least the period until the scheduled maintenance
Returns: The goal is $ 5 per sensor and $ 30 per controller

There are different types of hydrogen sensors, which differ in the way to discover the gas:

In many sensors palladium is used because it has a high adsorption capacity for hydrogen and palladium hydride forms. However, palladium -based sensors are strongly dependent on temperature, which at low temperatures leads to a high reaction time. They must also be protected from carbon monoxide, sulfur dioxide and hydrogen sulfide.
Sensors with optical fibers using surface plasmon resonance and can detect hydrogen at a contact point
The combination of nanotechnology with MEMS allows the production of sensors, which operate error-free at room temperature. The sensor is coated with a film of indium (III) oxide ( In2O3 ) and tin ( IV) oxide ( SnO2 ). In case of contact with hydrogen, this film swells and thereby produces new electrical connections.
Some sensors comprise a Schottky diode, the activation energy is available for the adsorption of hydrogen with palladium. A Schottky diode with a Pd / InGaP semiconductor can detect a concentration of 15 ppm of hydrogen in air.

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