Development And Application Of Circulating Water System Conductivity Instrument Based On Embedded System

With the transition of economic structure,the government and customers are paying more attention to cyclic utilization of water resource,more and more water treatment facility using circulating water system.Evaporation and accumulation of organic matter cause problems of scaling,corrosion,microorganism gather and sludge.It will have negative influences on the equipment operating in industry and central air-conditioning.It will influence thermal performance of central air-conditioning and increase operation loads to circulating water equipment.In order to protect equipment,ensure the safety,stabilization and efficient operation of water treating system,make water treating in the field of industrial,central air-conditioning and solar water heater,have important meaning in safety using of enterprises and residents.Firstly,the paper introduces the background of circulating water treatment system,and describes the meaning of conductivity in water treatment system.Secondly,it makes a detailed description of circulating water treatment system and principle of measurement;Lastly,it designs a five-electronic conductivity detection instrument based on embedded system used in circulating water treatment system.This instrument consists of conductivity sensor,conductivity detecting system,display of system operating.The five-electrode conductivity sensor is made by graphite;The conductivity detection instrument using STM32F407ZGT6 microchip which is based on ARM Cortex-M4 framework,the display instrument using a 7-inch TFTLCD,the measure and control software has transplant RTOS,which is uCOS-III.Sine wave is generated by CPU and other peripherals,get the conductivity signal by sensor,collect and deal signal by conductivity detection devices,using TFT-LCD to display.In the end,this paper introduces the development of hardware and software of circulating water conductivity instrument.After testing the hardware and software,it comes out that the instrument can control the conductivity of circulating water in a reasonable range with high precision.So,this instrument can be used in circulating water system.