What do you think of laser gas detection technology that can perform point, line, and surface detection? ? ?
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Laser gas detection technology: There are various approaches to using lasers for gas detection and analysis, including direct absorption measurement technology, wavelength modulation technology, cavity resonance technology, laser-induced fluorescence technology, laser Raman spectroscopy technology, and laser photoacoustic spectroscopy technology. Here, we mainly discuss the first two of these, which are what we commonly refer to as laser gas analysis techniques, namely tunable laser absorption spectroscopy, abbreviated as TDLAS. Basic principle: Each gas molecule has its own unique frequency at which it absorbs light energy; the intensity of absorption depends on the concentration of the gas molecules. The change in light intensity during the gas absorption process is given by Beer-Lambert’s law: I(v) = I₀(v)exp{-N×o(v)×Left}. Most gases exhibit spectral absorption; however, due to the differences in their molecular structures, some gases have more absorption lines, some have greater absorption intensity, and the absorption wavelengths also vary. Spectroscopy has thus become a widely used method for gas detection. TDLAS utilizes light passing through the gas to be measured (as shown in the figure); each gas absorbs light of specific wavelengths, and the higher the gas concentration, the stronger the absorption. The gas concentration is calculated by measuring the light energy that has been absorbed.
(1) Point type: Laser detector
(2) Linear type: Open-circuit laser gas detector. This linear gas detector utilizes laser technology to monitor gas leaks over a range of hundreds of meters. It can detect gas leaks at the ppm level; it is more sensitive than fixed-point gas detectors, has a wider detection range, and offers greater safety protection. Advantages: Fast response, good selectivity, strong interference resistance, low investment
(3) Linear type: With a handheld laser gas telemetry instrument, when the laser beam emitted by the instrument is directed at the target gas pipeline, if there is a gas leak, part of the laser beam will be absorbed. After passing through the leaking gas mass, the light is scattered and reflected back by background objects such as the ground or walls behind the gas mass. The scattered light is collected by lenses, then received by a highly sensitive InGaAs detector, where it undergoes photoelectric conversion. Through signal processing, it is possible to calculate the integrated gas concentration between the detector and the reflecting background objects.