5 results about "Cavity ring-down spectroscopy" patented technology

The invention provides a multi-site cooperative monitoring method and system based on an optical cavity ring-down spectroscopy technology, and the method comprises the following steps: constructing a multi-site cooperative monitoring network based on a plurality of greenhouse gas monitoring sites disposed in a target monitoring region; collecting a greenhouse gas sample gas at each site, and detecting the sample gas by using a greenhouse gas analyzer based on an optical cavity ring-down spectroscopy technology to obtain greenhouse gas concentration data; collecting greenhouse gas concentration data of each station, and carrying out filtering processing; validity evaluation is carried out through a data validity analysis module, standard gas calibration operation is carried out on stations needing standard gas calibration, and at least two other stations are controlled to be kept in a normal monitoring state in the calibration process based on a calibration locking mechanism, so that continuous monitoring of greenhouse gas by the multi-station cooperative monitoring network is maintained. The accuracy, stability and reliability of greenhouse gas monitoring are improved, and real-time and long-term monitoring can be realized.

The invention relates to the technical field of gas detection, in particular to a device and a method for detecting trace moisture in high-purity hydrogen bromide. The detection device comprises a pretreatment tank body used for receiving to-be-detected high-purity hydrogen bromide gas and removing impurities in the to-be-detected high-purity hydrogen bromide gas, the pretreatment tank body is filled with a pretreatment agent, one end of the pretreatment tank body is provided with a gas inlet, and the other end of the pretreatment tank body is provided with a gas outlet; the detection unit is communicated with the gas outlet of the pretreatment tank body and is used for detecting the moisture content of the pretreated gas, and the detection unit is based on an optical cavity ring-down spectroscopy principle; and the data processing and display system is electrically connected with the detection unit and is used for calculating and displaying the moisture content. The method comprises the following steps: performing gas pretreatment to remove impurities and then performing moisture detection. The whole detection process is high in automation degree, only several minutes are needed from gas entering the device to detection result obtaining, the requirement of real-time online detection can be met, and the analysis efficiency is effectively improved.

The invention provides a wavelength correction method and a gas analyzer based on cavity ring-down spectroscopy. The method comprises the following steps: a laser generates original laser and transmits the original laser to an acousto-optic frequency shifter; the acousto-optic frequency shifter performs frequency offset on the original laser based on the target wavelength to generate offset laser; the detector detects the original laser and the offset laser propagated by the optical cavity to obtain ring-down information of the original laser and the offset laser; the control unit identifies the offset information of the original laser relative to the target gas absorption peak based on the difference between the ring-down information of the original laser and the ring-down information of the offset laser, and sends a correction signal to the laser based on the offset information, and the correction signal is used for triggering the laser to adjust the target wavelength of the generated original laser based on the offset information. By generating the offset laser and analyzing the ring-down information difference, wavelength offset is recognized and corrected in real time, wavelength correction is achieved, the stability and precision of the gas analysis process are improved, and measurement interruption or additional hardware addition is avoided.

The application discloses a cavity ring-down spectroscopy multi-component gas concentration online monitoring method, and belongs to the technical field of gas monitoring; based on the light path propagation direction, a target optical cavity is divided into a front end layer, a core layer and a tail end layer, and a plurality of cavity ring-down spectrometers synchronously collect decay signals of each layer at a unified data collection time point to construct a hierarchical cavity ring-down matrix; a standard gas with a preset concentration is introduced at a calibration time point, initial values of gas concentrations of each layer are calculated, and a hierarchical concentration error matrix is constructed; envelope fusion processing is performed on the decay signals of each layer to obtain fused decay signals, and the fused decay signals are uniformly corrected based on a hierarchical error offset result; hierarchical equivalent gas concentrations of each layer are calculated, and a comprehensive concentration of multi-component gas is obtained through hierarchical collaborative weighting as an online monitoring result output, which can effectively suppress the influence of systematic errors on the monitoring result, and improve the stability, consistency and engineering applicability of multi-component gas online monitoring.

The application discloses a kind of optical cavity ring-down spectroscopy systems based on double optical path PDH mode-locking technique, including laser frequency feedback control module, laser phase polarization modulation module and light splitting modulation module.Laser frequency feedback control module utilizes integrated laser frequency stabilizer to adjust the laser frequency output by external cavity diode laser.Laser phase polarization modulation module realizes polarization and phase modulation by Mach-Zehnder modulator and integrated laser frequency stabilizer.Light splitting modulation module realizes the generation of two polarized perpendicular beams by fiber beam splitter, half-wave plate, Faraday rotator and polarizer etc., and maintains the real-time locking of laser frequency.One is PDH light, for modulating laser emission frequency;Another is probe light, for actual measurement.Fast switch ensures that the input of probe light is cut off when ring-down event occurs, thereby reducing interference and improving signal-to-noise ratio.The application has higher speed and accuracy, improves the efficiency and reliability of spectral analysis.