Applications Of Photoacoustic Spectroscopy In Oil-dissolved Gas Analysis

Photoacoustic spectroscopy is a new spectrum detection technology. With the Micro Signal detection technology, a strong light source (laser, xenon lights, etc.). The advent of photoacoustic spectroscopy and its application research has broad prospects at home and abroad. Since photoacoustic spectroscopy can detect very weak absorption signal, so the technology is widely used for trace analysis, people using photoacoustic spectroscopy detection of atmospheric pollutants. In medicine, general spectroscopic techniques due to the presence of light scattering problems, so the new photoacoustic spectroscopy by virtue of its design may be pretreated photoacoustic signal can be directly measured advantages are widely used in cell research, leukemia condition and early diagnosis of biological tissue research and novel photoacoustic Immunology diagnostic method. Photoacoustic effect and the modulation frequency, changing the modulation frequency gets information on the sample surface at different depths, it is to provide surface structure information at different depths destructive detection method.The so-called photoacoustic spectroscopy is based on the photoacoustic effect based on a discipline. Intensity can be modulated with a beam of monochromatic light irradiated to the sealing in the pool sample sound, light absorbed by the sample and to release the heat -excitation mode, the release of thermal energy by the sample and the surrounding medium the light modulation frequency periodic heating, resulting in medium to generate periodic pressure fluctuations, the pressure fluctuations can be a sensitive microphone or a piezoelectric ceramic microphone detected and obtained by enlarging the photoacoustic signal, which is the photoacoustic effect. If the incident monochromatic wavelength variable can be measured with wavelength -dependent optical acoustic signal spectrum, which is photoacoustic spectroscopy. Since photoacoustic spectroscopy measures the light absorbed by the sample size, and thus the reflected light, scattered light measurement such interference is very small, so the photoacoustic spectroscopy for measuring highly scattering samples, opaque samples, the absorption intensity of the incident light intensity weak absorption ratio of small samples and low concentration samples, etc., and whether the sample gas, crystals, powders, gel, etc. can be measured, it is common spectrum cannot do, so photoacoustic spectroscopy in the gas detection principle trace analysis area has its own unique advantages.Dissolved gas analysis (DGA) is the industry recognized prevent oil-filled electrical equipment failure is one of the most effective methods is divided into two kinds of offline and online testing. Traditional oil dissolved gas analysis method is the use of off- gas chromatography, has been by domestic large, medium and small substation general use. Off-gas chromatography with good selectivity, high performance separation, separation time, high sensitivity, wide application and mature technology, etc., but there are principles inherent defects, for example, there is human error degassing operations, monitoring manual correction curve will also increase the error; take oil samples from the oil separator and then to laboratory analysis, operating procedures are complicated and take a long time; addition, the development of insulation deterioration be fast or slow, preventive tests cannot find fault in real time the oil-filled electrical equipment online monitoring of the gas content has become an urgent need.In this paper, the principle of photoacoustic spectroscopy departure, focusing on photoacoustic spectroscopy detection method in oil dissolved gas analysis (DGA) in the field of application, combined with the actual use of photoacoustic spectroscopy to detect oil dissolved gas analysis, findings of the trial results demonstrate photoacoustic spectroscopy detection method in oil dissolved gas analysis (DGA) the feasibility of applying the field, and thus the related products or programs designed to provide guidance.