Chemical sensors drinking water

FICs are useful as electrochemical sensors, electrolytes and electrodes in batteries and in solid state displays (Farrington Briant, 1979 Ingram Vincent, 1984). If a FIC material containing mobile M ions separates two compositions with different activities of M, a potential is set up across the FIC that can be related to the difference in the chemical activities of M. By fixing the activity on one side, the unknown activity on the other can be determined. This principle forms the basis of a number of ion-selective electrodes LaFj doped with 5% SrF2 is used for monitoring fluoride ion concentration in drinking water. Similarly, calcia-stabilized-zirconia is used in cells of the type... 

Temperature sensors Another important parameter that is commonly measured in industrial process streams is temperature. Most chemical and biological reactions in industrial processes are known to be temperature dependent. The reliable and accurate determination of temperature in these cases is of paramount significance. Some of the industrial processes for which temperature measurement is frequently required include water treatment, waste-water treatment, conditioning of drinking water, sewage sludge treatment, and a wide range of chemical and biochemical processes. 

The fluorine sensor is extensively used conunerdally. The fluorine content can also be detected by chemical sensing and the principle of this device also belongs to type II. The base material is lanthanum fluoride, which is an excellent fluorine conductor, and which is stable even in aqueous solution. A typical plication is to measure the fluorine content in test water solutions. The principle of fluorine detection is based on the F concentration cell method. The detection limit is as low as 10 M, which covers most F" concentrations in drinking water. A fast response is one of the typical characteristics of the type-II sensor it is less than 3 minutes even if the F content is as low as 10" M. 

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