Micro gas chromatograph

The Sitrans CV process gas chromatograph determines information on the quality of natural gas including its calorific value, Wobbe index and density. The accuracy of the measurement is independent of the pressure of the sample and the ambient temperature.

A display on the device shows the measuring results. The device uses miniaturised detectors and valves made with MEMS (micro-electromechanical systems) technology. This means the system consumes only a minimum amount of carrier gas and electricity. Furthermore, it does not need an analyser shelter.

The detectors are highly linear so that only one calibration gas is needed, reducing operating costs and increasing availability. The automatic optimisation of the measuring parameters every time calibration is carried out makes the device very reliable.

The chromatograph determines the chemical composition, the superior and inferior calorific values, the Wobbe index and the density of natural gas in accordance with ISO 6976. Measurement components are methane up to nonane, nitrogen and carbon dioxide. Due to an internal sample switch function, up to four sample streams can be measured successively. The measuring accuracy is better than 0.1% and the repeatability better than 0.01%. The detection limit for pentane and higher hydrocarbons is between 10 and 50 ppm.

The modular design of the device allows for quick and easy maintenance. All the analytical components, including the oven, are integrated in an analytic module, which can be replaced within five minutes, reducing the overall maintenance time to half an hour. The Windows-based software is user-friendly, simple and clear. A password protection system prevents unauthorised access to the device’s parameters and results of analysis while a logbook documents all alarms and events.