Sensor Array-Based Optical Portable Instrument For Determination Of Ph Martínez Olmos, Antonio Capel Cuevas, Sonia López Ruiz, Nuria Palma López, Alberto José Orbe Payá, Ignacio De Capitán Vallvey, Luis Fermín Full-range optical pH sensor array OLED display Digital colour detector HSV colour space Portable instrumentation A portable optical instrument is presented that makes it possible to determine pH with a colorimetric sensor array. The use of four membranes containing acid-base indicators makes it possible to cover the full range of pH using the H (hue) coordinate measurements of the HSV colour space. pH sensitive membranes were directly cast onto a plastic support to form a two-dimensional array, located between an OLED display as the programmable light source and a set of digital colour detectors. The resulting microcontroller-based system is immune to optical and electrical interferences. A complete optical and electrical characterization and optimization of the hand-held instrument was carried out. The instrument was used to determine pH using a simple algorithm to select the sensor output that was programmed in the microcontroller. The initial eleven candidate pH membranes were reduced to only four, which permit to obtain reliable pH values. The pH response of the selected four sensing elements was modelled, and calibration curves were applied to a validation set and real samples obtaining positive correlations between the real and predicted data. 2023-11-07T08:10:06Z 2023-11-07T08:10:06Z 2011-02-23 info:eu-repo/semantics/article A. Martinez-Olmos, S. Capel-Cuevas, N. L´opez-Ruiz, A.J. Palma, I. de Orbe, L.F. Capit´an-Vallvey, Sensor Array-Based Optical Portable Instrument For Determination Of Ph, Sensors and Actuators B: Chemical (2010), doi:10.1016/j.snb.2011.02.052 https://hdl.handle.net/10481/85490 10.1016/j.snb.2011.02.052 eng info:eu-repo/semantics/openAccess