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

The invention relates to the field of cavity ring-down, in particular to a cavity ring-down spectrum detection system and method, and the system comprises a detection unit, a gas path system, a constant temperature control unit and a control and processing unit. The gas path system can be used for filling inert protective gas into the ring-down cavity and maintaining a micro-positive pressure state in a non-measurement period of the detection system, so that external pollutants and water vapor are effectively prevented from invading, and lens pollution and internal adsorption are reduced; the constant-temperature control unit is used for carrying out overall temperature control on the ring-down cavity and the gas path system and inhibiting signal drift caused by water molecule adsorption / desorption; and the gas path system adopts a low-adsorption material, a dead-cavity-free structure and a low-leakage sealing joint, so that the memory effect and the leakage risk are further reduced. The invention also provides a corresponding detection method which comprises the steps of micro-positive pressure maintenance, constant temperature control, strong purification, sample measurement and the like. According to the system and the method, the measurement precision and the stability are remarkably improved, the maintenance frequency and the startup purging time are reduced, and the maintenance requirement is reduced.

Disclosed is an optical feedback cavity ring-down spectroscopy system without phase control. The system comprises: a light source module, used for generating a laser of a predetermined wavelength; an optical feedback module, used for feeding back a part of the laser generated by the light source module into the light source module, and generating strong feedback or moderate feedback, so as to narrow the line width of the laser; an optical cavity module, used for increasing the effective action distance between the laser and a target detection substance, and exciting an optical cavity ring-down signal by means of achieving resonance between the laser and an optical cavity; a trigger light-cutting module, used to instantaneously cut off incident light of the optical cavity module to facilitate detection; a detection module, used to detect a transmitted optical signal outputted by the optical cavity module, convert the transmitted optical signal into a voltage signal, to be used as an optical cavity ring-down signal; and a data acquisition module, used to acquire the optical cavity ring-down signal outputted by the detection module, and perform exponential fitting on the optical cavity ring-down signal to obtain a ring-down time.

The invention relates to a standard gas preparation system and method based on an optical cavity ring-down spectroscopy detection technology, and is characterized in that the standard gas preparation system comprises a high-precision standard gas preparation host, a gas supply unit, a flow control unit, a gas mixing unit, an optical cavity ring-down spectroscopy in-situ online detection unit and an adjustment output unit; and the microcomputer of the high-precision standard gas preparation host is used for controlling the normal operation of each unit in the system. The standard gas preparation system can measure the concentration of a standard substance in situ in a high-pressure environment, is strong in representativeness, and can generate standard gas with any given concentration by monitoring feedback in real time and controlling the inlet and outlet of gas in the high-pressure gas cabin according to the feedback, so that the method is more flexible and applicable; and the method does not need to use expensive high-accuracy gas as the source standard gas, so that the manufacturing cost of the standard gas is greatly reduced.

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 application relates to a standard gas preparation system and method based on a cavity ring-down spectroscopy detection technology, characterized in that the standard gas preparation system comprises a high-precision standard gas preparation host, a gas supply unit, a flow control unit, a gas mixing unit, a cavity ring-down spectroscopy in-situ online detection unit and an adjusting output unit; a microcomputer of the high-precision standard gas preparation host is used for controlling normal operation of each unit in the system. The above-mentioned standard gas preparation system can measure the concentration of standard substances in-situ under a high-pressure environment, is representative, can generate standard gas with any given concentration by monitoring and feeding back in real time and controlling the in-out of gas in a high-pressure gas cabin according to the feedback, is more flexible and applicable, and since the method does not need to use high-accuracy gas which is expensive as a source standard gas, the production cost of the standard gas is greatly reduced.

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 invention discloses an optical feedback cavity ring-down spectroscopy system without phase control, and the system comprises a light source module which is used for generating laser with a predetermined wavelength; the optical feedback module is used for feeding back a part of laser generated by the light source module to the light source module to generate strong feedback or moderate feedback so as to narrow the laser line width; the optical cavity module is used for increasing the effective operating distance between the laser and a target detection substance and exciting an optical cavity ring-down signal by realizing resonance between the laser and an optical cavity; the trigger light cutting module is used for instantly cutting the incident light of the optical cavity module so as to facilitate detection; the detection module is used for detecting the transmission light signal output by the optical cavity module and converting the transmission light signal into a voltage signal as an optical cavity ring-down signal; and the data acquisition module is used for acquiring the optical cavity ring-down signal output by the detection module and performing exponential fitting on the optical cavity ring-down signal to obtain ring-down time.

The application provides a lung cancer breath mark detection system coupled with film separation and optical cavity ring-down spectroscopy, and belongs to the technical field of medical treatment; comprising the following steps: S1, preparation of a gas separation film; S2, coupling of the gas separation film with a CRDS system; S3, development of a lung cancer screening breath analysis system based on separation-sensing; the green and efficient film separation method is used to solve the problem of spectral interference that cannot be avoided by the laser-based selectivity in the detection of exhaled gas, a POCT gas sensing system based on separation-sensing and high selectivity and high sensitivity lung cancer screening breath analysis is developed, and a new technology is provided for lung cancer breath screening.

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.