The Design Of Portable ETongue For Real Time Water Pollution Detection

The paper introduces the design and application of the portable eTongue for realtime water pollution detection. The instrument can detect several trace metals (Zn, Cd,Pb, Cu, As, Hg, Fe) in water quickly.Firstly, the status of heavy metal pollution and the development of commondetection technology are introduced. The instrument adopts multiple measurementtechniques such as light-addressable potentiametric sensor and differential pulsestripping voltammetry.The instrument can be divided into four parts: the computer, the eTongue(including the electrodes and the electro circuit), the waterway (including the pumps,valves and pipes) and the system of supporting solution. The system features highreliability, high integrity, flexible configuration and wonderful extensibility. And thewaterway is designed to three sections, which are independent from each others.The software system is consisted of several modules including data processing,data communication, process control and data storage etc. The data processingmodule uses several methods such as outlier detection and correction, digitalfilters, curve correction, etc, to process the raw data and then store these results.The communication between the computer and the instrument is based onserial port RS232, and the message mechanism in Windows is used to implementthe communication among the modules in the software system.Finally, a lot of experiments are carried out to test the instrument. The resultsshow that the instrument, which consists of automatic sample injection and analysis,is not only brief but also quite suitable for measurement of trace heavy metals inwater.