The Design Of On-line Multi-parameter Detection System For Water Quality

With the technological progress and economic development,water pollution problems are becoming increasingly serious.Drinking water safety issues have been taken extensive attention.If the drinking water is polluted,it will cause great inconvenience for people's lives and also endanger people's health.Therefore,it is of great practical significance to strengthen the water quality testing of drinking water.According to the need of improving the drinking water quality inspection.That a set of on-line Multi-parameter detection system for water quality based on STM32 microcontroller is designed in this thesis.Drinking water for family life is detected for its main purpose.Then the test results is uploaded to the network server.So that the water quality of drinking water could be viewed by people at anytime and anywhere.Water pollution problems could be detected in time.The safety of family life could be protected.The hardware circuit and the design of the underlying driver of each sensor is mainly studied in this thesis.The design of the hardware circuit mainly includes the following parts,the power supply module circuit,TDS detection circuit,PH detection circuit,residual chlorine detection circuit,temperature detection circuit,TFT-LCD display module,serial port Wi-Fi communication module,JTAG module and so on.The hardware circuit takes the STM32 as the core,realizes the acquisition of the sensor output signal of the water quality detection sensor.The signal is sent to the STM32 after A/D conversion.After the data processing,the temperature,TDS value,PH value and residual chlorine Content,and through the serial port Wi-Fi module to the network server for users to view.The design of the software mainly includes data acquisition program,serial communication program,liquid crystal display program and other parts.That the overall workflow of the system and the work flow of each module is described in detail in this thesis.In the design of this thesis,the test results temperature is compensated for taking into account the temperature and electrode differences on the test results.And the sensor electrode is calibrated for two aspects.It is showed in the experiments that the online water quality testing system designed in this thesis can automatically detect a number of water quality parameters.Compared with the commonly used water quality test pen,the detection of accuracy and stability are improved more obviously.The experimental process and the results gets the desired results of requirements and objectives.Therefore it can be applied to the testing of household drinking water quality.