Bosch expertise aids development of an innovative solution

Citation

(2000), "Bosch expertise aids development of an innovative solution", Sensor Review, Vol. 20 No. 2. https://doi.org/10.1108/sr.2000.08720baf.007

Bosch expertise aids development of an innovative solution

Bosch expertise aids development of an innovative solution

Keywords: Environmental monitoring, Sensors

Environmental Monitoring and Control Ltd (EMC) has worked with Bosch Automation Technology to develop an innovative solution to the long-standing industry-wide problem of limited range and poor response times in oxygen analysers.

Combining EMC's expertise as an analyser manufacturing company committed to applying novel sensor inventions to industrial problems together with Bosch's sensor and technical back-up, the two have developed an analyser that enables fast and accurate measurement over the whole range of oxygen partial pressures.

The use of traditional potentiometric Nernst sensors, which show a good response at low oxygen partial pressures, in the absence of reducing gases, is an acceptable solution for most analysers. However, for applications outside this limited range the sensor becomes unresponsive and can experience large-scale errors. In situations where oxygen concentration is very high it can actually take up to two minutes before a stable measurement is produced.

Rather than use the more conventional measurement system of partially stabilised zirconia electrolyte, EMC's OX 100 (see Plate 6<) series of oxygen analysers utilise a patented amperometric technique which allows fast accurate measurements to be made over the whole range of oxygen partial pressures from 10-20 atmospheres to greater than one atmosphere pressure.

Plate 6EMC's OX 100 series oxygen analyser incorporating an innovative solution to the long-standing industry-wide problem of limited range and poor response times in oxygen analysers

The key to this development was a source of partially stabilised zirconia sensors. To satisfy this requirement EMC turned to Bosch Automation Technology.

The combination of the Bosch sensor and EMC's innovative unit ensures accurate measurement of oxygen concentrations below 2 percent and near linear output response for higher concentrations.

This unique versatility of measurement greatly enhances the sensitivity and response times of the sensor, especially at high concentrations of oxygen. The end result is an analyser that maintains accuracy throughout the entire oxygen range, eliminating the need for alternative measurement techniques.

Versatility is also the key to the variety of applications for the EMC analyser, including the monitoring of combustion gases, and the control of lean burn applications where traditional Nernst sensors have poor accuracy, especially where high oxygen pressures need to be measured.

The OX 100 analyser has already been put to use by one customer in an application to measure the high oxygen levels inside a kiln producing superconductor powder. Owing to the high cost of the powder it is essential that the atmospheres and temperatures are monitored constantly during the process. Since the introduction of the analyser the company has reported that it has been able to significantly improve the quality of its product.

Through working closely with Bosch to select a suitable sensor, EMC has created a device that overcomes the traditional drawbacks of Nernst based analysers.

For further information please contact: Dr Ron Henson, Environmental Monitoring & Control Ltd, Castle Works, Stafford ST16 2ET, UK. Or Andy Oswick, Robert Bosch Limited, Meridian South, Meridian Business Park, Braunstone, Leicester LE3 2WY, UK. Tel: +44 (0) 116 281 4488.