The principle and standard method of ozone determination by ozone detector

We all know that ozone detectors are mainly used in ozone preparation workshops (ozone generators, ozone workshops, etc.), chemical, petroleum, paper, textile, pharmaceutical, and flavor and fragrance industries, water treatment, food and medicine sterilization workshops, etc. . This method uses the characteristic absorption characteristics of ozone to ultraviolet light with a wavelength of 254nm and detects the ozone concentration by measuring the change in the intensity of ultraviolet light through ozone according to the Lambert-Beer law. This method is not only suitable for detecting the concentration of ozone in the gas, but also for detecting the concentration of ozone dissolved in water. It has been adopted by my country as the standard method for determining ozone in ambient air.

The electrochemical method mainly involves the measured ozone gas being in contact with the instrument in a diffusion manner, and reacting, outputting a stable electrical signal. The gas concentration value can be stably displayed on the display with data. The principle of the ultraviolet absorption method is that ozone has the maximum sparse absorption of wavelength ultraviolet light, and the ultraviolet light at this wavelength will be attenuated when passing through the ozone layer, which conforms to the Lambert-Beer law. At present, the ultraviolet absorption method has been adopted as the standard method for ozone analysis in the United States and other countries. The ultraviolet absorption method has the advantages of high detection accuracy, good stability, and little interference from other oxidants. The disadvantage is that the price is higher.

Spectroscopy is a method of analysis by measuring the wavelength and intensity of emitted light, absorbed light, or scattered light generated by a substance under the action of light. In spectral analysis, the analytical method established based on the selective absorption of light by substances is called absorbance spectroscopy.

Scientists have discovered that the ozone layer can absorb ultraviolet light. Studies have shown that ozone only has a maximum absorption coefficient for ultraviolet light with a wavelength of 253.7nm. At this wavelength, ultraviolet light will attenuate through ozone, which conforms to the Lambert-Beer law: this principle has been The United States and other countries as the standard analysis method of ozone: The ozone detector adopts the principle of ultraviolet absorption method, uses a stable ultraviolet light source to generate ultraviolet light, and uses a lightwave filter to filter out other wavelengths of ultraviolet light, and only allows the wavelength of 253.7nm to pass. After passing through the sample photoelectric sensor, after passing through the ozone absorption cell, it reaches the sampling photoelectric sensor. By comparing the electrical signals of the sample photoelectric sensor and the sampling photoelectric sensor, and then calculating through the mathematical model, the ozone concentration can be obtained.