Modular basic device for extractive gas analysis permits selection of very small measuring ranges

The Siprocess GA700 series from Siemens Industry Automation Division is a new extractive gas analyser family with an innovative platform concept. A modular basic device is used with local user interface, communication interfaces, power supply, basic electronics, and software. Various analyser modules are integrated into the basic device depending on the measuring task. Each of these modules consists of the actual analyser and the sensor electronics, including the evaluation software and required interfaces. As the first in the range, the Oxymat module measures oxygen according to the paramagnetic alternating pressure principle. The Oxymat module ensures absolute linearity and allows extremely small measuring ranges to be selected in one device: 0 to 0.5 percent with a detection limit of 50 ppm, as well as 0 to 100 and 99.5 to 100 percent.

The Siprocess GA700 basic analyser with enclosures for rack or wall mounting can accommodate two analyzer modules. Module replacement is simple and user-friendly, and can be carried out on site without having to replace the basic device. The parameters already set for the measurement are automatically transferred from the basic device to the replacement module. The modules are temperature-controlled to permit quick and easy replacement without repeated recording of the temperature characteristic. Furthermore, they operate independently of ambient temperature variations, and thus provide highly stable measurements. The analyser modules are suitable for ambient temperatures up to 50 degrees Celsius, have a uniform operating concept, and are equipped with a local user interface comprising display and keyboard. The high-resolution graphic display outputs the measured values in analog and digital forms. The operating software has been radically changed, with the focus on clear menu navigation and comprehensive user prompting. For example, an installation wizard is available for initial commissioning, and provides clear and explicit instructions for guidance through the process. The software is provided in 12 languages for global use. During operation, the modules signal servicing intervals, calibration requirements, or remaining lifetime of parts subject to wear, thus providing the basis for predictive maintenance concepts.

The new Oxymat module for measuring oxygen is suitable for demanding applications where high requirements exist regarding reliability and measuring quality. This is ensured by modern electronics, simple operation, and a physical unit matched to the measuring task. Corrosive gas mixtures can also be measured thanks to the use of special materials in the gas path. The detector unit does not come into contact with the sample gas, and is therefore suitable for use in harsh atmospheres while simultaneously ensuring a long service life.

An Ultramat module for measuring infrared-active gases and a Calomat module for hydrogen and noble gases are also planned.

Extractive gas analyzers are used in process plants to continuously determine the concentrations of gases. They are used, for example, for safe monitoring of process flows, for ensuring high product quality, or for the reliable determination of emissions. Different physical or electrochemical procedures are used depending on the components to be measured.