Gas Analysers

Gas analysers from Witt determine gas concentrations in gas mixtures quickly and precisely and are highly versatile. State-of-the-art sensors and intuitive controls allow easy handling of the gas analysers, guarantee exact analysis results and ensure the quality of your processes. Depending on the type of application, the gas analysers can be supplied separately or integrated into gas mixing systems.

As stationary or portable gas analysers for sampling or continuous gas analysis, they are available for a wide range of technical gases and applications. Witt offers gas analysers for example for oxygen, carbon dioxide, helium, hydrogen or methane. The gas analysers are used, for example, in food and pharmaceutical industries, in hospitals and medical applications, to control gas supply lines in thermal processing plants and numerous other industrial applications.

As special versions of the gas analysers, Witt also offers devices for indoor air monitoring as well as for humidity measurement or dew point analysis of gases.

Gas analysers for the control of protective atmospheres in the food and pharmaceutical industries

Gas analysers are essential for quality control when a process involves packaging under protective atmosphere. The quality control can be done either as continuous gas analysis directly during the packaging process or downstream to the packaging process by means of sample analysis.

In continuous gas analysis, an analysis module is integrated into the gas mixing system. The gas analyser then continuously monitors the composition of the gas mixture.

Sample analysis is carried out as quality control in almost all companies packaging with modified atmospheres. A needle is used to remove a gas sample from the packaging. Probably the world's best-known model from the Witt product range is the handheld gas analyser OXYBABY®. This reliable assistant for checking protective atmospheres is one of the best-selling gas analysers in the food industry.

Witt gas analysers are reliable and require only a very small quantity of gas. Thus, they are also suitable for packaging with a very small gas-containing headspace, i.e. a small amount of inert gas in the packaging. Because of this, Witt gas analysers are also used for checking packaging of medical products in the pharmaceutical industry, such as vials, ampoules or blister packs.

Non-destructive random sampling with gas analysers

The nondestructive control of MAP packaging is also possible with Witt gas analysers. Using state-of-the-art and safe laser technology, the oxygen content can be reliably determined in transparent packaging.

Gas analysers for highest quality in thermal processing plants

Protective and surface finishing demands highly accurate gas mixtures. But these highest quality steel finishing processes also requires the necessary control and safety. So for these processes Witt offers integrated gas analysis systems in the gas mixers, which continuously monitor and optimise the composition of the forming gases.
The combination of Witt gas analysers with gas mixers assures safety when handling flammable gases.

Modern gas sensors as the heart of gas analysers

The technical heart of the Witt gas analysers is the actual measuring cell. For the measurement of oxygen and carbon dioxide, the following measurement principles are applied:

1. Zirconia measuring cells

Zirconia measuring cells are characterised by their high response speed and a relatively long service life. Their sensitivity also allows measurements in the ppm range. On the other hand, the ceramic sensor is very sensitive to pressure surges and has a high power consumption due to the necessary heating. Zirconia gas analysers measuring cells are often used in stationary analysers.

2. Electrochemical measuring cells

Electrochemical measuring cells are relatively inexpensive and require no supply voltage. Disadvantages are the relatively short lifetime at too high oxygen concentrations, and a relatively long response time or measurement time. In addition, a frequent calibration of the gas analyser is necessary.

3. Paramagnetic measuring cells

With paramagnetic measuring cells, a long-term stable measuring signal with long calibration intervals can be achieved. Since it is a physical measurement principle, the cells have a long service life. On the other hand, these relatively expensive measuring cells do not allow analysis in the ppm range and are susceptible to errors at high gas pressures. They are preferably used at high oxygen concentrations.

4. Infrared sensors

For the analysis of carbon dioxide gas, analysers with infrared sensors are usually used. These are relatively inexpensive and low-wear.

Depending on the application, Witt also relies on other technologies for gas analysis, such as the principle of thermal conductivity for the determination of binary gas mixtures or the separation process in gas chromatographs.

MAP Gas Analysers brochure