The company: Siemens AG is a very well known major company which operates in the electrical-engineering industry. Since several decades Siemens A&D is well known as a manufacturer of process gas analysers. Only recently the portfolio has been extended to laser diode based equipment for in-situ process control. Siemens CT is engaged since more than a decade in the field of gas sensing for automotive, industrial and medical applications. Two fundamentally new types of solid state sensors – based on a new metal oxide material and a gas-sensitive FET device – have been developed. These technologies are just entering several promising applications. The department Sensors and Actuator coordinated successfully quite a number of EC and nationally funded projects to the related subjects. As a supplement to low cost solid state gas sensors with limited performance, Tuneable Diode Laser Spectroscopy (TDLS) was introduced in 1997. These activities were supported by close links to the neighbouring photonics department, which made available the first tailor made DFB diode lasers for TDLS. Development activities were focussed then on Natural Gas leak detection. A gas sniffer exploiting the advantages of TDLS - like long term stable calibration, high dynamic range of the Methane concentration (10 ppm to 100 %vol) and highest selectivity - was developed in collaboration with a mayor European gas supplier. Moreover the identification or Natural Gas in contrast the other sources of Methane was enabled by simultaneous detection of Methane and Ethane. In the framework of the EC project VOGUE a remote Methane leak detector was developed up to last year in collaboration with a couple of European gas suppliers from different countries. This Laser ‘pointer’ allows detecting leaks up to 30 m. An open laser beam reflected from any surface (pavement house wall) is analysed. Methane along the pathway generates the desired signal. Marketing activities for the laser ‘pointer’ these of instrument are ongoing today.

The resources: The gas sensors group is equipped with labs for developing and testing the electronic sensor hardware as well as characterising laser diodes. For testing gas sensors especially for cross sensitivities different multi-gas mixing units are available. Environmental test chambers allow testing sensors under extreme operating conditions. Gas and oil burners allow operating gas sensors with real exhaust gas. For reference purposes a number of commercial gas analysers, an FTIR and a mass spectrometer are available. Furthermore Siemens Corporate Technology provides access to a wide variety of advanced analysis techniques and manufacturing tools.

The role in the project: Siemens develops a versatile gas sensor platform based on the new MIR VCSEL using Wavelength Modulation Spectroscopy (WMS). The platform serves within the project for demonstrating the performance of the new VCSEL and forms the basis for a new generation of gas sensor product for emission and immission monitoring, safety and health care. Due to its outstanding performance the laser based monitors are expected to substitute conventional monitors in the near future.