High Tech in the Home

Given this situation, it is not surprising that, over the last few years, products based on platinum thin film technology have been finding their way into the home. With the growing use of electronic control systems in the new generation of domestic appliances, platinum temperature sensors have been more widely used in ovens where they have replaced electromechanical regulators such as capillary tubes, solid expansion thermometers and NTC thermistors. Typical sensor applications in the food preparation sector are shown in Fig. 5.3. 

Even conventional hotplates can be fitted with a continuously variable temperature control thanks to platinum thin-film sensors. The encapsulated platinum sensor is positioned so that it is in contact with the cast iron plate from below and thus able to register the temperature of the hotplate. Normally the power supplied to the plate is regulated by a stage switch. The increased control sensitivity is made possible by incorporating electronic circuitry capable of interpreting and acting upon the sensor signals. 

Similar technology is also being used in induction hotplates and radiant heating elements and in the silicon nitride hotplates currently under development and which are characterized by an excellent heat transfer between heat source, sensor and saucepan. Gas hotplates could also be provided with the latest in domestic temperature sensing technology by fitting them with electric temperature control circuitry. 

Intelligent process control based on platinum temperature sensors and tailored electronics provides an effective method of improving both kitchen safety and the user friendliness of kitchen appliances, and also contributes to reducing energy consumption. 

A major growth area for platinum sensor technology is to be found, above all, in ovens. The sensors are used to fulfil two main functions  

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