A New TOC Measuring Device Based on UV Oxidation and Electrical Conductivity Measurement

The content of total organic carbon is an important indicator for ultrapure water. The existing TOC measuring device based on UV oxidation uses a large volume oxidation cell, which leads to low oxidation efficiency. Also, using NDIR sensors to measure the carbon dioxide content will generate a series of complex processes and eventually causes low measurement efficiency and accuracy. To address these problems, we designed a new type of TOC measuring device combining UV oxidation and electrical conductivity measurement. A small volume oxidation cell with precise structure is designed and applied to this device. The optimum volume was obtained through a series of comparative experiments, both oxidation rate and accuracy are improved. The hardware and software development of electronic control system are carried out based on a high performance and low power embedded micro-controller. Through a series of experiments, it is proved that this design not only improves the measurement efficiency, but also has the advantages of high accuracy, low cost, no pollution and low power consumption.