An interference-tolerant nitrate smart sensor for Wireless Sensor Network applications

Abstract

11As a major contaminant in ground water, nitrate determination is a common practice in 12 environmental analysis, especially the continuous and simultaneous monitoring of its 13 concentration at many different points.

IoT Technologies in Chemical Analysis Systems: Application to Potassium Monitoring in Water

“…In this application, an interference rejection service is implemented based on a mechanism that considers that the influence of the interfering agents on the measurement obtained can be compensated for by adjusting a straight line of regression, which can be applied to correct the obtained measurements when the interfering species are known. This algorithm is detailed in [ 2 ], where it was applied to a smart nitrate sensor and implemented by the Perseo module, which is included in the FIWARE platform.…”

“…This information, which already has high added value (it is in the cloud, free from interference, conveniently stored, and available to applications), was reprocessed again to avoid errors due to sensor malfunction. For this purpose, the TMR module follows the algorithm proposed in [ 2 , 3 ], where the application of the TMR technique to environmental monitoring is described in detail. As a final result, the TMR offers us a single measurement that is immune to the malfunctioning of “real” sensors, since it either provides error-free measurement or indicates the existence of errors, which prevents erroneous decisions from being made (based on erroneous information); in this way, it is also possible to determine which sensor or sensors are giving erroneous results, with a view to their repair.…”

“…In some of our previous work [ 2 , 3 ], we focused on the research and development of techniques that allow for the implementation—by means of expert systems—of intelligent sensors that provide an increase in reliability and the rejection of interference from the point of view of efficiency, low cost, and reduced energy consumption.…”

A New Ammonium Smart Sensor with Interference Rejection

“…The ideal ion selective electrode should be interference-free [ 15 ], although what most manufacturers try to achieve is to keep these interferences to a minimum. Nevertheless, recent progress in the field of communications and microelectronics (including data management) permits technologically advanced systems to be obtained [ 16 ].…”

“…Nevertheless, recent progress in the field of communications and microelectronics (including data management) permits technologically advanced systems to be obtained [ 16 ]. In fact, Capella and co-workers addressed this issue in the determination of nitrates [ 15 ] and reached a satisfactory solution, with interferences being eliminated. Nevertheless, this solution did not consider the possibility of ISE malfunctions and their errors, be they transient (incorrect measurements at random) or permanent (drifting in the electrodes).…”