Hydrogen (H₂)
air-Q with a hydrogen sensor
Description:
Most of the hydrogen on Earth is bound up in water. That is why it is found both in the Earth's atmosphere (as water vapor) and in the oceans and other bodies of water, as well as in all living organisms. Without hydrogen, the transport of substances within the body would not be possible.
Currently, hydrogen is important to industry primarily as a potential energy carrier for reducing CO2 emissions. To this end, hydrogen is produced using electricity generated from a primary energy source (preferably a renewable one).
Hydrogen is not dangerous to the human body. Even outdoors, there is little danger, as it dissipates immediately after escaping from storage tanks. However, in enclosed spaces, the gas accumulates near the ceiling because it is lighter than air. The gas is highly flammable when it escapes: the discharge of electrostatic charge from clothing provides sufficient energy.
Leaking liquefied hydrogen can cause frostbite upon contact. For this reason, transport tanks and storage areas must be secured particularly well. Adequate ventilation of the premises is generally recommended.
Hydrogen limit values:
Since the gas has no direct effects on human health, no limit values have been established.
However, there are physical limits. The flammability range of hydrogen in air is between 4 and 76 percent by volume. At concentrations of 18 percent or higher, the mixture is explosive (detonating gas). The autoignition temperature in air is 560 °C.
| Denomination | Hydrogen Limit Values |
| Lower flammability limit | 4 % |
| Upper flammability limit | 76% |
| Lower Explosivity Limit | 18% |
Consequences of a concentration that is too high:
At high concentrations, there is a risk of explosion. To prevent this, areas where hydrogen is stored must be well ventilated and equipped with a ceiling-mounted exhaust system.
Source of H₂:
Gaseous hydrogen is rarely found in its natural state on Earth. It occurs mainly in a combined form, such as water.
Hydrogen can be produced industrially using various methods (e.g., electrolysis).
Sensor used:
Hydrogen is measured in the air-Q using an electrochemical sensor. H₂ molecules “adhere” to the sensor surface and generate a measurable current. The sensor is highly accurate. The disadvantage of all electrochemical sensors is cross-sensitivity. The only known cross-sensitivity of the H₂ sensor is to carbon monoxide. When this gas is present, a slight increase in H₂ is also indicated.
Measuring hydrogen:
Use the air-Q air analyzer to measure hydrogen, as well as other gases and pollutants in indoor air, in real time. The hydrogen sensor is available for purchase in the store.
More measured values / sensors
