Investigation of a New Conditioning Method for Improved Performance of Non-Nernstian Sensors

Abstract

The article reports on a new conditioning technique referred to as the pulsed discharge technique to improve the performance of non-Nernstian potentiometric sensors. In this method, the sensor is energized through a series of positive and negative pulses between the electrodes with discharge phases in between. The sensor response is extracted from the discharge characteristics, which depend on the type of gas and its concentration. The data is presented as a combination of variables derived form the discharge characteristics. In this study, a 'La0.8Sr0.2CrO3/YSZ/Pt' sensor configuration was used to investigate this technique. The sensor baseline drift, response, and recovery time was found to improve when the device was subjected to PDT. Further, a 27-fold increase in sensor response was observed per 1000 ppm of NO compared to the device tested in the absence of PDT. The PDT technique is thought to change the interfacial defect concentration by voltage pulses in the solid electrolyte. Subsequent measurement of the relaxation rate after perturbation in the presence of the target gas gives rise to unique discharge characteristics. It is emphasized that this study has to be seen as an initial approach that demonstrates the potential of the novel conditioning principle for improving the non-Nernstian sensor performance.