Resistance measurements, zirconia sensors

It was hrst reported in 2001 [32] that the evaluation by impedance spectroscopy of a biased zirconia sensor with an attached LaFeOa-SE has shown that only the electrode resistance is a function of NO2 content. Consequently, impedance spectroscopy offers a method for directly probing the electrode reactions that are the basis for mixed-potential-type gas sensors [67]. As a result of further development by using impedance spectroscopy in zirconia-based gas sensors with oxide-SEs, a new type of YSZ-based sensor for detecting total NO and HCs at high temperatures has been proposed recently [2, 14, 21, 62, 74, 96-100]. In this case, the change in the complex impedance of the device attached with a specific oxide-SE was measured as a sensing signal. 

Sensors for measurements of oxygen in molten steel are the most important application in liquid metal sensing. As an electrolyte MgO partially stabilized, zirconia is used because of its high thermal shock resistance due to phase transformations. 

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