ACITEK's Water Ec Meter

This project is a collaboration from Taiwan. The biggest challenge of this project lies in the large number and long distance of monitoring points. There are a total of 45 monitoring points, and each point needs to measure three parameters (pH, dissolved oxygen and temperature). Transmitting the data to the central control room using the traditional 4-20mA would waste a lot of signal lines and be unstable.In this case, I proposed to change the original 4-20mA output of the instrument to RS485. In this way, the 45 monitoring points can be connected in series and finally transmitted to the central control room through one data bus. This not only reduces the number of signal lines but also brings convenience to the on-site installation and commissioning.In addition, dissolved oxygen is an extremely important indicator in the aquaculture industry. In the breeding room, the control range of dissolved oxygen can be set according to the dissolved oxygen range that the farbred objects are suitable for. The computer controls the chip to automatically turn on and off the aerator within the set control range of dissolved oxygen based on the data collected by the dissolved oxygen sensor. Reasonable use and configuration of the aerator not only save electricity but also reduce mechanical wear. It also achieves the greatest efficiency with the least input.Computer management software can analyze the disease pattern of the money fish based on the range of dissolved oxygen changes, issue disease warnings in a timely manner, and prevent the occurrence of diseases. Analyze the degree of deterioration of water quality based on the changes in dissolved oxygen, and take timely measures for treatment, such as sewage discharge, water replacement, adding aerators, and digestion bacteria, etc.For the selection of dissolved oxygen electrodes, I gave up the expensive fluorescence dissolved oxygen electrode and chose the traditional polarographic dissolved oxygen electrode. The polarographic dissolved oxygen electrode not only measures accurately but also has a low maintenance cost. It only requires regular addition of electrolyte and replacement of membrane sleeves.The pH value of water quality is also quite important. Based on the changes in pH value, the deterioration of water quality and the generation of harmful substances such as ammonia nitrogen, sulfides, and nitrites, as well as the degree of decomposition and oxidation of organic matter like residual feed, are analyzed. Through the alarm system, a water quality analysis report is submitted and warning information is sent. So as to take various measures in time.For the installation method of the pH electrode, I chose the submerged installation, which is convenient for users to clean the electrode in the future and has received unanimous praise from users. This set of solutions has helped the client save a significant amount of costs, achieving an automated breeding base integrating monitoring and control, and has become a model in the prosperity fish breeding industry.

The project is of great significance as it concerns the water safety of the entire residents and crops on Chongming Island. Previously, without automatic monitoring of whether seawater was backflowing, seawater often entered Chongming Island, affecting the growth of crops and resulting in low crop yields. It has increased the cost of water quality treatment in the early stage of waterworks.Under such circumstances, the Chongming Water Conservancy Bureau proposed to promptly control the entry of seawater into the island. This project was highly challenging as each gate was far from the monitoring room, making remote control difficult. Through the knowledge I had acquired, I realized that the most significant difference between seawater and fresh water lies in their varying salt content. Therefore, I adopted a salinity analyzer to control the seawater.When choosing electrodes, another problem was encountered. The traditional PT100 temperature compensation is greatly affected by distance, which will affect the accuracy of the data. I resolutely adopted a 30K thermistor as the salinity and temperature compensation. It was not affected from 50 meters to 100 meters, accurately monitoring the high and low tides of the seawater. This project is of great significance and has benefited the entire Chongming Ecological Island.