Development of the real-time pH sensing system for array sensors

This study employs the tin oxide (SnO2) films as the sensing membrane for fabricating array sensors and combines these sensors with a real-time sensing system. Furthermore, the four-point probe, X-ray diffraction (XRD) and scanning probe microscopy (SPM) were applied in identifying the surface characterization of the SnO2 pH electrode. This study presents an array pH sensing system to obtain the signals from the SnO2 pH electrode. Additionally, an array sensing system reduces the errors of the single sensor and the real-time sensing system is employed as the testing system to reduce testing time. This paper presents the real-time sensing system that includes eight readout circuits and one data acquisition card using software (Labview) to control. Experimental results proved the surface characterization of the SnO2 pH electrode and this pH sensing system that monitored signals from each sensor simultaneously. Therefore, this paper presents an efficient real-time pH sensing system for array sensors.