Improving the limits of detection in potentiometric sensors

Authors Franc van der Bent, Erik Puik, H.D. Tong, C.J.M. van Rijn
Published in Measurement Science and Technology
Publication date 12 November 2015
Research groups Smart Systems for Healthy Living
Type Article


From the publisher: Potentiometric sensors will generally suffer from unwanted responses as a result to changing temperatures by generating an electromotive force. Typically, this voltage drift has a non-linear character and therefore it is difficult to compensate using linear algorithms implemented in the analogue domain. A solution is proposed to improve the sensor characteristics by combining the digitized output of two CO2 rubidium silver iodide sensors with a specially designed digital algorithm to improve the limits of detection (LOD). Experiments show that this method has the capability to improve the LOD of the sensor with a factor 4.5x during temperature variations of 22 °C over a measurement period of 22 h. It enables potentiometric sensors to be used in low power wireless sensor networks for long term air quality control. Furthermore, the influence of depletion of the rubidium silver iodide electrolyte layer can be effectively compensated by determining the decay of the active layer according to the Nernst equation. Knowing the function of depletion over time helps to correct the sensor output and thereby improves the accuracy of the sensor.

Language English
Published in Measurement Science and Technology
Year and volume Volume 26 12
Key words Sensors, Temperature measurements

Smart Systems for Healthy Living