Abstract
An algebraic method for quantifying gases, using an electronic system composed of an integrated sensor and a microprocessor, is described.
The integrated sensor is fabricated by using thick film techniques. It has three different elements on an alumina substrate. The elements are kept at around 400°C by a Pt heater mounted on substrate back. Since these elements are made from different semiconductor oxides, they posess different sensitivities to propane, carbon monoxide generated by incomplete combustion, and ethanol. First, ethanol is quantified by using the LaNiO3 element. Then, using the ethanol concentration, propane and carbon monoxide quantifications are carried out by the SnO2 and WO3 elements, respectively.
The microprocessor stores data tables prepared on the basis of the gas sensitivity functions in its memory. After table look up, gas quantification is performed algebraically.
