Since ozone is a chemically unstable gas, collecting and measuring its content in the air and water within a short period of time has become a difficult problem. As mentioned above, to ensure the purification and sterilization of water by ozone, various parameters need to be controlled. Among them, only the measurement of ozone concentration is difficult. Some ozone generator manufacturers do not test themselves, and do not know the concentration of ozone produced by their products. Some manufacturers use the difficulty of testing to exaggerate the performance of their products, causing extremely bad effects, and even affecting people's ozone sterilization Ability to trust.

　　 It should be said that the ozone concentration test is not difficult now. In practical applications, the ozone concentration is the basis for ensuring the disinfection effect, and it is also a necessary means to identify the true performance of the ozone generator. Therefore, while promoting the application of ozone, the measurement of ozone should be promoted at the same time.

        1. Iodometric method: The most classic measurement method in the past was to use ozonated gas to free the iodine in the potassium iodide solution to develop color, and then titrate it with sodium thiosulfate to reduce it to colorless, calculated by the amount of sodium thiosulfate consumed Ozone concentration. This method is intuitive, and the equipment is cheap, but it requires chemical testing equipment such as various drugs, washing bottles, measuring cylinders, balances, burettes, etc., which is inconvenient to use and easy to be interfered by other oxidants (such as N0, CL, etc.). It is still the standard measurement method in China.

2. Ultraviolet absorption method: use the maximum absorption value of ozone for ultraviolet light with a wavelength of 254nm to attenuate the ultraviolet light in an ozone atmosphere, and then obtain data output through optoelectronic components and electronic circuits (comparison circuit, data processing, digital-to-analog conversion) , This method is accurate and can be continuously measured online. It has been selected as the standard method by the United States and other advanced industrial countries, but the instrument is more expensive, and is generally used as a testing unit, production and scientific research unit.

3. Electrochemical method: using the electrochemical reduction effect of ozone in water on the electroactive surface, the current change curve in the electrochemical circuit is proportional to the ozone concentration in the solution. This instrument has a data output function, which can be measured online and can realize ozone The closed-loop feedback control of the generator is cheaper than the ultraviolet method and has a smaller volume. It is currently used in large-scale water treatment projects.

　　 4. Colorimetric method: It is the same chemical method as the iodometric method, which uses the coloration or decolorization of the reaction of ozone to chemical reagents to determine the ozone concentration. It can be used with a variety of chemical substances such as potassium iodide, o-tolidine or indigo dye. It can be directly observed with the naked eye and compared with standard color tubes or cuvettes. It can also be detected with a spectrophotometer. This method is simple and easy to perform, and the cost is not high. The current level in China is suitable for promotion, but the tested drugs are disposable consumables.