Abstract: A method of making a sensor element comprises: combining coarse aluminium oxide with fine aluminium oxide and a binder to form a mixture, milling the mixture to form a base slurry, mixing a supported catalyst with the base slurry and a fugitive material to form a final slurry, applying the slurry to a sensor element precursor over at porous protective layer at least in an area opposite a sensing electrode, and calcining the sensor element precursor to form a calcined sensor element with a catalyzed coating over at least a portion of the porous protective layer. The coarse aluminium oxide has a coarse agglomerate size and the fine aluminium oxide has a fine particle size less than the coarse agglomerate size.

Abstract: A method and system for controlling the temperature of an oxygen sensor is provided wherein the method includes obtaining an oxygen sensor, a heating device, heating control device and a signal generator, wherein the oxygen sensor includes a reference cell and wherein the heating device is communicated with the oxygen sensor and the heating control device, introducing a fixed frequency sinusoidal signal to the reference cell through a voltage divider resistor so as to create a response signal, wherein the response signal is responsive to the temperature of the reference cell, buffering the response signal so as to create a buffered signal, applying the buffered signal to a high pass filter so as to create a filtered signal having a filtered signal magnitude, wherein the filtered signal magnitude is inversely proportional to the temperature of the reference cell, measuring the filtered signal so as to create a temperature signal responsive to the filtered signal magnitude and communicating the temperature sign