Recently, Xiaohan has received many questions from friends about our technical research. Today, Xiao Han invited Li Gong, our engineer of Hanhai optoelectronics, to give you a detailed answer.

Q：The core technology of Hanhai optoelectronics is laser absorption spectroscopy. What is laser absorption spectroscopy?

A："Laser absorption spectroscopy technology" relies on "laser" as the monitoring method, that is, "the laser with a specific wavelength will be absorbed by a specific target gas", and the absorption intensity is related to the concentration of the target gas "as the technical principle.

When we want to detect a certain target gas, we should set the laser with a specific absorption wavelength in advance, and actively emit the laser to detect the target gas. We only need to study the reflected laser spectrum to get the gas concentration of the detected gas.

For example: the target gas methane CH4 only absorbs 1654nm wavelength laser, as long as the laser emitting 1654nm wavelength is selected as the light source, the real-time monitoring can only be carried out for methane CH4, so as to obtain the detection data. If there is no methane CH4 in the air of the monitored area, the 1654nm laser will not be absorbed and the system will not react.

Q:What does fingerprint mean?

A：The laser wavelength absorbed by a specific gas is unique and has the one-to-one correspondence property of fingerprint.

Q:What does passive mean?

A:Passive means that the detection terminal of the monitoring site is a pure optical equipment, which can work continuously without power supply. The laser emission control device for detection is installed in the remote control room, and the detection laser is transmitted to the detection terminal on the spot through optical fiber.

Q:Why don't Hanhai photoelectric products need calibration?

A:Traditional electrochemistry, infrared and other technologies will drift with the passage of time, but the laser will not. The wavelength of the laser absorbed by each specific gas is constant, and the wavelength of the laser is also constant, so there is no need to calibrate.

Q:What is wavelength?

A:Wavelength refers to the distance of wave propagation in a vibration period. That is, along the propagation direction of the wave, the phase difference between two adjacent vibrations is 2 π The distance between the points of. wavelength λ It is equal to the product of wave velocity u and period T, i.e λ= uT。 Waves of the same frequency travel at different speeds in different media, so the wavelengths are different.   Then the laser wavelength is the output wavelength of the laser.

Q:Can the laser detector accurately monitor the harmful gas, and can it provide the specific parameters of harmful gas, such as concentration, coverage (volume), positioning coordinates and other information related to post-processing, etc?

A:The monitoring network composed of several fixed reflection laser gas telemeters can realize the real-time online monitoring of gas distribution, distribution concentration, moving speed, moving direction, and the positioning coordinates cannot be displayed.

Q:Does the equipment need regular maintenance and is it affected by weather and climate change?

A:Our equipment is maintenance free. The detection effect will not be affected by weather and climate change.

This is because the laser is very stable, the laser wavelength will not change, so there will be no drift and so on, so it does not need to be calibrated regularly; Second, the protection level of the equipment itself is very high, basically above IP65, dustproof and waterproof, not affected by weather and climate change.

Q:Can laser itself cause gas combustion and explosion?

A:No. Because the laser power of the equipment is very low, below 10MW, the energy is very small, and it will not cause gas combustion.

Q:Is the laser detector stable?

A:Very stable. Laser detection equipment is made of semiconductor laser, explosion-proof optical glass and other materials. The shell is also high-strength stainless steel, and its properties are very stable. At the same time, the detection method is contactless, and there will be no physical loss.

Q:Does the laser applied by the product hurt the human body?

A:No harm. Laser is divided into four levels, our products are controlled in the safest level, can be

used at ease.