Infrared absorption for gas measurement

Functionality

The light is absorbed at the wavelength of the absorption band. This means that energy is extracted from the light. This energy is used to cause the atoms of a molecule to vibrate. Two light beams are used in an infrared gas sensor: One measuring beam with a wavelength of 3.4 mm, and a second with a different wavelength as a reference. Both beams are focussed on light detectors. If the measuring beam suddenly receives less energy than the reference beam, there must be a gas present that is drawing energy from the measuring beam. Compur uses infrared absorption for the measuring devices in the Statox series, as this measuring principle can also be used to detect inert gases that cannot be measured using other methods, e.g. because there is no oxygen present (which would be required by a heat tint sensor, for example) or because corrosive products are formed during oxidation that would poison a catalytic sensor, for example.

Advantages of infrared technology

There is no risk of poisoning the sensors, which means that the intervals for maintenance and calibration can be longer. It is also important that no oxygen is required for measurement.

Another advantage of infrared measurement technology is that the failure of the radiation source or a detector, for example, is detected as total absorption and thus triggers an alarm. This means that a fault never goes unnoticed.

Safe infrared technology from Compur

The sensors of the Statox devices, which work with infrared absorption, are particularly suitable for hydrocarbons such as those found in the chemical and petrochemical industries. The longevity and relative freedom from maintenance help to save the budget without having to compromise on safety in gas detection. Compur has been developing and producing gas detection and warning devices for more than fifty years, and these have become established on the market. These include, in particular, the Statox series of detectors.