2results about How to "Sensitive to temperature changes" patented technology

This invention discloses a reusable diaphragm wall leakage detection device, comprising a detection tube disposed on the outside of the diaphragm wall, a heating device and a measuring device disposed inside the detection tube, the heating device being connected to an external temperature controller, and the measuring device being connected to an external fiber optic demodulator. Both the fiber optic demodulator and the temperature controller are connected to a leakage analysis host, which analyzes the fiber optic demodulator and provides signals to the temperature controller to adjust the heating device. The detection tube is placed by drilling holes on the outside of the diaphragm wall joint, eliminating the need to weld the detection device to the diaphragm wall reinforcement cage. The servo motor controls the opening and closing turntable and connecting rod to achieve deployment / retraction, allowing the sensor and heating band to be in close contact with the detection tube, resulting in more accurate detection and easier recycling, significantly saving costs. The temperature controller controls the heating band for nonlinear heating, maintaining a constant temperature of the groundwater around the detection device, making it more sensitive to temperature changes caused by leakage water and improving measurement accuracy.

This invention relates to the field of marine environmental monitoring technology, and discloses a temperature, salinity, and depth sensing system and demodulation method based on a polarization-maintaining fiber optic π-phase-shifting grating. The system includes a polarization-maintaining fiber and a π-phase-shifting fiber grating, with the π-phase-shifting fiber grating inscribed on the polarization-maintaining fiber and serving as a single sensing unit. The reflection spectrum of the sensing unit contains reflection peaks along both the fast and slow axes, with an ultra-narrow linewidth transmission window introduced by the π-phase shift at the center of each peak. A salinity-sensitive thin film is coated on the π-phase-shifting region of the sensing unit, covering the π-phase-shifting region and extending into a local area of ​​the π-phase-shifting fiber grating, but not covering the entire grating. By locally coating the salinity-sensitive thin film on the π-phase-shifting region of a single polarization-maintaining fiber optic π-phase-shifting grating, and simultaneously extracting the characteristic wavelength changes of its fast and slow axis reflection center wavelengths and transmission window wavelengths, a sensitivity matrix is ​​used to achieve synchronous decoupled measurement of the three parameters of temperature, salinity, and depth.