84 results about "Quartz tuning fork" patented technology

The invention discloses a light-induced thermoelastic spectrum trace gas detection device and method based on an echo wall mode microcavity. The device comprises a first signal generator, a lock-in amplifier, a laser device control unit, a first laser device, a laser beam collimation unit, a gas chamber, a focusing lens, a tuning fork, an echo wall mode microcavity, a coupling medium, a second laser device, a second signal generator, a photoelectric detector and a computer, the emergent laser is focused to the interdigital root of the tuning fork through the focusing lens; laser output by the second laser device is transmitted by the coupling medium and coupled into the echo wall mode microcavity in an evanescent wave form, the echo wall mode microcavity deforms, the resonant wavelength of the echo wall mode microcavity in the transmitted spectrum moves, and the concentration of the gas to be detected in the gas chamber is inverted according to the displacement of the resonant wavelength. The problems that a quartz tuning fork is large in thermal noise and weak current signals are easily interfered by an electromagnetic field are solved.

The invention relates to a QEPAS detection system based on resonance tube coaxial coupling configuration. The QEPAS detection system comprises a laser signal emission unit, a photoacoustic detection unit and an electric signal acquisition unit which are connected in sequence, the photoacoustic detection unit comprises an air inlet, an air outlet, a resonant cavity, a reflecting mirror and a quartz tuning fork; wherein the centers of the resonant cavities, the reflectors and the quartz tuning fork are located on an optical transmission path, the resonant cavities are arranged at the center of the photoacoustic detection unit and distributed on the two sides of the quartz tuning fork, and the reflectors are oppositely installed at the two ends of the resonant cavities; the quartz tuning fork is mounted at the gap of the resonant cavity; the exhaust port and the gas inlet are formed in the two sides of the resonant cavity respectively, background gas and target gas enter the photoacoustic detection unit from the gas inlet, and after detection is completed, mixed gas is exhausted out of the photoacoustic detection unit from the exhaust port. Compared with the prior art, the resonance characteristic of the resonance tube is utilized to enhance the photoacoustic signal, the coaxial structure optimizes the acoustic environment, and efficient and accurate detection of trace gas can be realized.

The invention relates to the technical field of gas sensing detection, and discloses a gas detection method and system based on a quartz tuning fork enhanced photoacoustic spectrum. The method comprises the following steps: constructing a standardized continuous tuning fork signal data stream; dynamically segmenting the data stream based on the gas concentration interval, and extracting time domain and frequency domain features in parallel in each segment to form an initial feature vector; dynamically adjusting an anomaly judgment threshold according to the jump amplitude of the adjacent segment feature vectors, and scanning and screening out an effective analysis interval of a stable concentration state according to the anomaly judgment threshold; performing cross-domain coupling compensation on the feature vectors in the effective interval to generate enhanced feature vectors; and finally, performing reverse traceability reasoning through a gas leakage propagation model based on the enhanced feature vector, and outputting a leakage source position identifier. The device can adapt to a dynamically changing concentration field, and the reliability and traceability positioning capability of gas detection in a complex environment are improved.

The invention relates to a device for preparing a tuning fork type scanning probe microscope probe, the device is composed of a base, a tuning fork fixing frame, a needle tip clamping frame, a dispensing support, a microscopic observation instrument and a laser cutter, and the tuning fork fixing frame, the needle tip clamping frame, the dispensing support, the microscopic observation instrument and the laser cutter are all fixedly installed on the base. The laser cutter comprises a laser device base and a laser device, and the laser device is installed on a lifting support of the laser device base, located over the quartz tuning fork fixing frame and used for cutting the bonded needle tip in a non-contact mode. The device provided by the invention solves the problems that the tip is easy to damage during the bonding of the tuning fork probe and the performance of the quartz tuning fork probe is reduced because the tip is too long, thereby improving the reliability of the manufactured tuning fork type scanning probe microscope probe.

The invention provides a quartz enhanced photoacoustic spectrometry detection system environment gas interference correction method which can be applied to the technical field of photoacoustic spectrometry gas detection. The method comprises the following steps: analyzing vibration-translation relaxation time and infrared absorption peak intensity of each gas to be detected; the to-be-detected gas with the vibration-translation relaxation time exceeding the time threshold value and the absorption peak intensity larger than the intensity threshold value is selected as comparison gas; dividing the laser of the comparison gas into a first laser beam and a second laser beam according to a preset proportion; using the first laser beam to excite a sound wave signal and detecting by a quartz tuning fork to generate a tuning fork electric signal; the second laser beam is enhanced and absorbed by a multi-reflection absorption cell and then is detected by a photoelectric detector to generate a light intensity electric signal; establishing a neural network model taking the tuning fork electric signal, the light intensity electric signal and the environment gas component vector as input and taking the to-be-detected gas concentration vector as output; and correcting the concentration of the to-be-detected gas under the interference of the environmental gas in real time through the trained neural network model.

The present invention discloses an intelligent multi-parameter oil quality monitoring device, comprising: a housing with a detection end and an output end at both ends, a resonant cavity and a detection cavity are arranged inside the housing, a particle detection channel and an oil port are provided on the housing; a monitoring component, including a sensing circuit module, a tuning fork resonance sensor, a temperature sensor and a microfluidic chip, the tuning fork resonance sensor includes a quartz tuning fork, the microfluidic chip includes a capacitor, and the capacitor includes electrode plates. This intelligent multi-parameter oil quality monitoring device integrates the temperature sensor, the tuning fork resonance sensor and the microfluidic chip inside the housing. By installing the housing on the oil pipe, multiple parameters such as the viscosity, dielectric constant, temperature, abrasive particle size, density, etc. in the oil can be monitored simultaneously, so as to accurately judge the oil quality, avoid false alarms, and perform data transmission through the sensing circuit module, with high integration, small volume and strong anti-interference ability.

The invention provides a cantilever beam probe of an atomic force microscope, a preparation method and an imaging method, and relates to the technical field of semiconductor testing. The method comprises the following steps: fixing a cantilever beam of a first type of atomic force microscope probe with a nanoscale needle tip at the head end on a needle tip of a second type of atomic force microscope probe in a curing connection mode, the cantilever beam probe of the second type of atomic force microscope takes the nanoscale needle tip of the first type of atomic force microscope probe as the needle tip of the cantilever beam probe of the second type of atomic force microscope; wherein the second type of atomic force microscope probe is a micron-sized needle tip, and the micron-sized metal needle tip is formed on a cantilever beam of the quartz tuning fork; one surface, back to the nano-scale needle tip, of the cantilever beam of the first-type atomic force microscope probe is fixedly connected with the micron-scale needle tip, and the fixedly connected position is close to the tail end of the cantilever beam of the first-type atomic force microscope probe; the problem that when a traditional qPlus probe is used for magnetic domain imaging of a magnetic material, enough resolution is difficult to achieve can be solved.

The invention discloses a photoacoustic spectrum trace gas detection device and method based on a secondary demodulation technology. The device comprises a tunable laser, a laser collimation device, a focusing lens, a gas chamber, a quartz tuning fork resonance circuit, a first lock-in amplifier, a trigger capture circuit, a phase modulation circuit, a second lock-in amplifier and a control and signal acquisition device. In the aspect of automatic tracking of the frequency, the quartz tuning fork is integrated into an oscillator circuit, and automatic tracking of the laser modulation frequency is achieved. The oscillator circuit can automatically adjust the output according to the current resonant frequency of the quartz tuning fork, and ensures that the laser is always modulated at the optimal frequency. In the aspect of continuous phase modulation, traditional fixed phase setting is replaced, the phases of electric excitation and photoacoustic excitation are continuously modulated, and pure photoacoustic signals are separated by using two lock-in amplifiers, so that a complex phase calibration process is avoided, and the accuracy and stability of signal detection are improved.

The invention provides a resonant bionic cilia vector hydrophone based on a quartz tuning fork and an underwater acoustic system, and relates to the technical field of micro-mechanical electronics. A vibration detection mechanism in the hydrophone comprises two quartz tuning forks located in a first axial direction and two quartz tuning forks located in a second axial direction, the first axial direction is perpendicular to the second axial direction, one end of each quartz tuning fork is fixed, and the other end of each quartz tuning fork is connected with a vibration acquisition mechanism; and the vibration acquisition mechanism is connected with the quartz tuning forks and is used for driving the two quartz tuning forks in the same axial direction to generate symmetrical frequency deviation under the action of sound waves. According to the embodiment of the invention, the excellent frequency stability and strain sensitivity of the double-end fixed tuning fork can be utilized to realize efficient conversion of sound signals and generation of corresponding electric signals, digital signal output can be conveniently realized, high-sensitivity detection of the sound signals can be effectively realized, the influence of common-mode signals can be inhibited, the anti-interference performance is good, and the detection precision is high. And the underwater sound detection effect is greatly improved.

The invention provides a quartz tuning fork gyroscope angular velocity compensation method and a quartz tuning fork gyroscope, and relates to the technical field of inertial sensors, the method comprises the following steps: collecting zero offset data and AGC data in a test temperature interval of the quartz tuning fork gyroscope; dividing the AGC data into a plurality of fitting intervals; for each fitting interval, performing unary linear fitting on the AGC data and the zero offset data, and establishing an AGC-zero offset compensation model; using an AGC-zero offset compensation model to calculate compensated zero offset data; and compensating the angular velocity of the quartz tuning fork gyroscope by using the compensated zero offset data. According to the quartz tuning fork gyroscope angular velocity compensation method provided by the invention, under the condition that a temperature sensor does not need to be added, relatively small zero offset data can still be obtained, the zero offset data shows better stability, hysteresis errors and drifting phenomena of the quartz tuning fork gyroscope can be effectively inhibited, and the accuracy of the angular velocity compensation of the quartz tuning fork gyroscope is improved. And the full-temperature zero offset performance of the quartz tuning fork gyroscope is improved.

The application discloses a kind of chirp modulation photo-thermal-optical spectrum resonance frequency and concentration synchronous measurement method and system, belong to photo-thermal-optical spectrum field, comprising: S1, generating chirp modulation signal driving laser, produces modulated laser beam;S2, the modulated laser beam is inducted after passing through gas to the surface of quartz tuning fork excitation photo-thermal-optical signal demodulation obtains first harmonic signal;S3, using lorentz line function fitting the first harmonic signal;S4, according to fitting result, the center resonance frequency position of quartz tuning fork is calculated;S5, whether the center resonance frequency position of the quartz tuning fork is located in the center of first harmonic signal;If not, adjust chirp modulation signal initial frequency repeats S1-S5, until the center resonance frequency position of quartz tuning fork is located in the center of first harmonic signal;S6, according to fitting result, response coefficient is calculated, and inversion obtains gas concentration information.The application can realize high-precision measurement of gas concentration and real-time correction of resonance frequency.

The application relates to the technical field of accelerometers, and provides a quartz vibrating beam accelerometer sensitive structure, which comprises a quartz flexible beam arranged at one end of a rigid beam, a quartz mass pendulum arranged at the other end of the quartz flexible beam, and a quartz tuning fork vibrating beam structure connected with the rigid beam at one end and connected with the quartz mass pendulum at the other end. The quartz vibrating beam accelerometer sensitive structure provided by the application is provided with the quartz flexible beam, the quartz mass pendulum and the quartz tuning fork vibrating beam structure, all of which are made of quartz crystal materials, so that the matching of the material thermal expansion coefficient can be improved, and the temperature drift problem caused by the mismatching of the material thermal expansion coefficient is solved.

The application discloses a quartz enhanced photoacoustic spectroscopy detection method and system using optical feedback, and belongs to the technical field of optical feedback. The method comprises the following steps: controlling the phase of optical feedback according to a laser based on a first reflector and a second reflector; matching the cavity film size of a laser and an F-P cavity; establishing stable optical feedback of the laser according to the phase of optical feedback; transmitting the laser passing through a polarizer to a fourth reflector, refracting the laser into the F-P cavity matched with the laser through a CaF2 window mirror, and passing the laser passing through the F-P cavity through the middle of the first resonant tube, the second resonant tube and the prong of the quartz tuning fork, so as to generate a photoacoustic signal based on the stable optical feedback, enhance the photoacoustic signal based on the first resonant tube and the second resonant tube, and detect the spectrum based on the enhanced photoacoustic signal. The application improves the anti-interference of detection.

The utility model discloses a light-emitting diode (LED) integrated photoacoustic cavity structure, which comprises an acousto-optic cavity shell, an acousto-optic cavity body is arranged in the acousto-optic cavity shell, gas is filled in the acousto-optic cavity body, and a quartz tuning fork base is arranged at the top of the acousto-optic cavity shell; the quartz tuning fork is clamped in the quartz tuning fork base, and the quartz tuning fork is inversely arranged in the cavity body of the acousto-optic cavity downwards along the longitudinal direction, so that the structure is compact, and the occupied space is reduced; a lens is installed in the side wall of the acousto-optic cavity shell, an LED lamp is installed in the acousto-optic cavity shell, the LED lamp directly faces the lens, the LED lamp is small in size, and the occupied space is reduced. Light emitted by the LED lamp is focused by the lens and then irradiated to gas in the cavity of the acousto-optic cavity to generate a photoacoustic signal, and the quartz tuning fork absorbs the photoacoustic signal.

The invention discloses a gas absolute concentration calibration-free measuring device and method based on a photoinduced thermoelastic spectrum. The device comprises a signal generator, a laser, a laser collimation system, a laser intensity modulator controller, a laser intensity modulator, a gas chamber, a lens, a quartz tuning fork, a lock-in amplifier and a computer. The invention provides a gas absolute concentration calibration-free measurement method based on a photoinduced thermoelastic spectrum by utilizing an intensity modulation technology on the basis of the photoinduced thermoelastic characteristic of a quartz tuning fork, and the method avoids the unavoidable calibration technical process in the photoinduced thermoelastic spectrum technology all the time. And a new technical scheme is provided for solving the problems of weak anti-interference capability and poor long-term stability of a sensor system caused by the method. The detection device disclosed by the invention has the advantages of high sensitivity, strong disturbance immunity, low cost and the like.

This invention provides a quartz gyroscope circuit, including a closed-loop drive circuit. The closed-loop drive circuit includes a drive interdigitator, a drive terminal circuit, and a controller. The drive terminal circuit converts the drive response charge signal generated by the drive interdigitator into a drive response voltage signal and transmits the drive response voltage signal to the controller. The controller generates an original digital reference signal, adjusts the frequency and amplitude of the original digital reference signal based on the drive response voltage signal to generate a drive voltage signal, and transmits the drive voltage signal to the drive terminal circuit. The drive terminal circuit amplifies the drive voltage signal and applies the amplified drive voltage signal to the drive interdigitator so that the oscillation frequency of the drive interdigitator is at the resonant frequency of the quartz tuning fork, and the oscillation amplitude of the drive interdigitator is within a preset amplitude range. This invention addresses the shortcomings of existing analog quartz gyroscopes, where the oscillation frequency cannot operate at the resonant frequency and the oscillation amplitude is unstable.

The application discloses a photoacoustic spectrum sound detector and a gas detection device, which comprises a first Helmholtz resonant cavity, a quartz tuning fork and a second Helmholtz resonant cavity. The two Helmholtz resonant cavities are coaxially connected by a cylindrical barrel and a thin tube. When laser is incident from the light transmission window of the first Helmholtz cavity, passes through the gap between the vibrating arms of the quartz tuning fork and is emitted from the window of the second Helmholtz cavity, the two Helmholtz resonant cavities resonate and amplify the sound wave signal excited by the laser beam, so that the sound pressure near the vibrating arms of the quartz tuning fork is enhanced, the environmental noise and the window noise are suppressed, and the signal-to-noise ratio of the quartz tuning fork in detecting the sound wave signal near the vibrating arms is improved. In the application, the Helmholtz cavity can resonate and amplify the sound wave, thereby improving the output signal amplitude. In the measurement process, the Helmholtz cavity can suppress the environmental noise and the window noise, further improve the signal-to-noise ratio and improve the gas detection precision.

The invention discloses a QEPAS probe gas sensor based on gradient refractive index optical fiber collimation and a detection method. The sensor comprises a gradient refractive index optical fiber collimator used for receiving laser and performing collimation; the first acoustic microresonator is used for guiding the collimated laser beam and the to-be-detected gas to excite and generate a photoacoustic signal and enhancing the intensity of the photoacoustic signal; the right-angle reflecting mirror is used for receiving the collimated laser beam output by the first acoustic micro-resonator and turning over the propagation direction of the collimated laser beam; the second acoustic micro-resonator is used for guiding the collimated laser beam after the propagation direction is turned to continue to be excited with the gas to be detected to generate a photoacoustic signal and enhancing the intensity of the photoacoustic signal; the quartz tuning fork is used for detecting a photoacoustic signal generated by excitation and converting the photoacoustic signal into a current signal; and the signal modulation and demodulation system is used for demodulating and calculating the gas concentration according to the current signal. According to the invention, while the size of the probe is greatly reduced, the convenience of optical path installation and the long-term stability of optical performance are greatly improved through the integrated design.

The application discloses a Fourier photoacoustic gas detection device and method, and belongs to the technical field of gas detection. In view of the limited anti-interference ability of a sound signal and the low detection sensitivity of an existing Fourier transform photoacoustic spectrum, a Fourier photoacoustic gas detection device is designed. A supercontinuum broadband light source is used as an excitation light source of a photoacoustic effect, the broadband light source is subjected to unified intensity modulation through an intensity modulation assembly and phase modulation through an interferometer assembly. After the broadband interference light emitted through double modulation interacts with gas molecules, wide-spectrum mixed sound waves are generated, a quartz tuning fork sound measurement assembly extracts resonance components and converts the resonance components into electrical signals. The generated electrical signals are sequentially subjected to processing through a signal amplification assembly, a phase-sensitive demodulation assembly and a Fourier transform assembly, and the processed signals are used for component discrimination and concentration inversion of a target gas.

Spectroscopic sensor for characterizing the absorption or determining the concentration of solid materials or liquid samples based on the photoacoustic effect, comprising - a device into which the liquid or solid sample to be analyzed is inserted or placed, - at least one laser in modulation mode to excite the material-specific molecules, - at least one sound transducer for detecting the sound pressure wave, - a device for detecting and processing the photoacoustic signal, characterized in that at least one sound transducer in the form of a quartz tuning fork (QTF) is used, the resonance frequency of which corresponds to the laser modulation frequency, that an acoustic resonator of a certain geometry, which is placed on the sample and has the same resonance frequency as the QTF, is used, that the laser modulation frequency corresponds to the resonance frequency of the resonator, and that the gas which fills the resonator shows as little or no absorption as possible in the wavelength range of the laser.

An anti-interference photo-thermoelastic spectroscopy gas detection device and method are disclosed. In the anti-interference photo-thermoelastic spectroscopy gas detection device, a laser source is used to emit a laser beam matching the absorption characteristics of the gas to be measured; an optical switch is connected to the laser source and is used to switch the laser beam to a detection optical path or a background optical path; a gas cell contains the gas to be measured, and laser collimation modules are arranged at both ends of the gas cell to form the detection optical path; a reference cell contains background gas, and laser collimation modules are arranged at both ends of the reference cell to form the background optical path; a laser focusing module is arranged at the end of the detection optical path and the background optical path to focus the beams from the detection optical path and the background optical path, and a quartz tuning fork generates a photo-thermal signal based on the beams; a signal processing module is used to analyze and process the photo-thermal signal and calculate the concentration of the gas to be measured.

The invention provides a gas detection method and a gas detection system, and belongs to the technical field of spectral measurement, and the method comprises the following steps: carrying out collimation processing on a laser beam through a collimating lens; the wavelength of the laser beam is matched with the A band of the target gas; after the collimated laser beam penetrates through the gas in the medicine bottle to be detected, focusing the emergent laser beam to a quartz tuning fork by using a focusing lens; the quartz tuning fork converts the received optical signal into an electric signal; the absorption spectrum of the target gas is obtained along with the change of the wavelength of the laser, and then the concentration of the target gas in the medicine bottle to be detected is determined. The intensity of a traditional transmission absorption measurement mechanism is improved through the photoacoustic effect, limitation of medicine bottle refraction and internal shielding on long optical path construction is avoided, the requirements of the system for optical alignment precision and spatial layout are greatly reduced, and miniaturization and engineering applicability of equipment are achieved while high sensitivity is guaranteed.

The application provides a quartz vibrating beam accelerometer with enhanced temperature environment adaptability, wherein a TO package of a sensitive structure is not fixedly installed to an accelerometer shell in a conventional metal connection mode, but is fixed to an inner wall of the shell through a ring-shaped glue body, so that the influence of external environment temperature change can be reduced, and the temperature performance of the accelerometer is improved; a heat insulation baffle is installed between a circuit and a head of the sensitive structure, so that the temperature gradient between double beams of the sensitive structure caused by the start-up temperature rise of the circuit can be effectively reduced, and the start-up time of the accelerometer is reduced.

The invention relates to the technical field of laser spectrum and photoelectric detection, in particular to a multi-component absorption spectrum detection device and method based on a super-continuum light source, and aims to solve the problem of simultaneous high-sensitivity detection of multiple gas components in the prior art. The detection device comprises a supercontinuum light source, an acousto-optic modulator, an optical fiber collimator, a sample gas cell, a diffraction grating, a rotary displacement table, a quartz tuning fork detector, a data acquisition card and a computer control unit, the rotary displacement table rotates around the axis of the rotary displacement table; and the diffraction grating and the quartz tuning fork detector are fixedly arranged on the rotary displacement table.

The application provides a quartz tuning fork resonator and a manufacturing method thereof, which comprises a base, a pair of vibration arms formed on the base, and a counterweight region formed at an end of the vibration arms away from the base, wherein an upper surface of the counterweight region is formed with a metal film layer, a blank gap is left between an edge of the metal film layer and a physical edge of the counterweight region, and the thickness of the metal film layer gradually decreases from a central region to an edge region. The application improves the controllability of film layer distribution by setting the blank gap and the gradient metal film layer with a central thickness and an edge thickness, completely inhibits the metal vapor superposition of the edge and the sidewall of the counterweight region from the structural level, eliminates the local stress concentration, and improves the long-term frequency stability.

The application discloses an integral cavity enhanced LITES gas concentration detection system and a design method thereof, relates to the LITES gas concentration detection technology, and aims to solve the problem that the prior art cannot consider safety, precision and sensitivity simultaneously. In the system, a quartz tuning fork is arranged at a central position of an integral cavity; laser generated by a laser generating device enters a gas absorption cell, and transmitted light formed after target gas absorption is incident on the integral cavity; the transmitted light acts on the quartz tuning fork in a back-and-forth process in the integral cavity; an electric signal output by the quartz tuning fork is collected by a signal collection card, a target signal component is obtained by demodulation of a lock-in amplifier, and a data processing device is used for calculation according to the target signal component to obtain the target gas concentration. The method comprises the following steps: determining optical structure parameters of the integral cavity, and assembling the integral cavity according to the optical structure parameters; and adjusting the position of the quartz tuning fork and the angle of laser entering the integral cavity, so that the laser can repeatedly act on a sensitive area of the quartz tuning fork in a back-and-forth process in the integral cavity.

The invention provides a digital demodulation type quartz MEMS tuning fork trimming device, and belongs to the field of MEMS tuning fork trimming. The device comprises an upper computer and a quartz MEMS tuning fork which are respectively connected with a first controller and a second controller. The upper computer is used for sending a first driving command to the first controller and sending a second driving command and a third driving command to the second controller; the second controller is used for controlling the quartz MEMS tuning fork to work in a gyro function mode according to the second driving command and the first parameter when a driving end mass block of the quartz MEMS tuning fork is roughly repaired; and the fine trimming module is used for performing linear frequency sweeping on the quartz MEMS tuning fork according to the third driving command during fine trimming to obtain a target mechanical orthogonal item, and determining that fine trimming of the driving end mass block is completed when the target mechanical orthogonal item reaches the standard. The trimming efficiency and precision can be considered through double-stage trimming and automatic control, and meanwhile the trimming cost is reduced.

A gas concentration sensing apparatus and a gas concentration measurement method. The gas concentration sensing apparatus comprises a sensor (100), a radio wave generator (200), and a signal processing module (300), wherein the radio wave generator (200) is electrically connected to a signal input end (101) of the sensor (100), and the signal processing module (300) is electrically connected to a signal output end (102) of the sensor (100); the sensor (100) comprises a quartz tuning fork (110) and a sensing micro-wire (120) that are electrically connected; the sensor (100) is used for having a gas to be measured introduced thereto, and allowing the sensing micro-wire (120) to absorb the gas to be measured; the radio wave generator (200) is used for emitting a vibrating radio wave to the sensor (100), such that the quartz tuning fork (110) and the sensing micro-wire (120) resonate upon receiving the vibrating radio wave, and transmitting a mechanical resonance signal to the signal processing module (300); and the signal processing module (300) is used for collecting the mechanical resonance signal and converting same into an electrical signal of a resonance frequency. In the solution, the characteristic that the overall resonance frequency of a quartz tuning fork (110) and a sensing micro-wire (120) changes with the concentration of a gas to be measured is used to directly obtain a corresponding concentration value of the gas to be measured, thereby achieving a simple and efficient measurement process.

The invention relates to the technical field of trace gas optical sensing, in particular to a photoacoustic spectrometry gas detection system and method based on a hollow-core optical fiber and a quartz tuning fork, and the system comprises a signal generation module, a laser modulation module, a hollow-core optical fiber enhanced detection module and a signal processing module, the system performs long-range interaction with to-be-measured gas in the hollow-core optical fiber by modulating laser, thermal expansion generated after light energy is absorbed is transmitted to the mechanically coupled quartz tuning fork through the optical fiber wall, the quartz tuning fork converts vibration into an electric signal through a piezoelectric effect, and finally the gas concentration is obtained through treatment. According to the invention, the bottleneck that the optical path is limited in the traditional technology is broken through, the detection sensitivity is greatly improved, and the application potential in trace and complex environment gas detection is expanded.

The invention provides an analog signal amplitude modulation circuit, a quartz tuning fork gyroscope circuit and a quartz tuning fork gyroscope, the amplitude modulation circuit comprises an operational amplifier U1, resistors R1, R2, R3 and R4 and a JFET, the JFET is represented by Q1, the number of the resistors R1 is two, an input signal of the amplitude modulation circuit is a high-frequency input signal ui, and an output signal of the amplitude modulation circuit is a high-frequency output signal uo; current generated by a high-frequency input signal ui enters the two branches at the same time, for the first branch, the high-frequency input signal ui flows to the ground after passing through one resistor R1 and parallel connection of R3 and Q1, and input voltage of the in-phase end of the operational amplifier is partial voltage of parallel connection of R3 and Q1; for the second branch, the current generated by the high-frequency input signal ui flows to the ground after passing through another resistor R1 and another resistor R2, and the current generated by the high-frequency input signal ui also flows into the inverting input end of the operational amplifier; in addition, the current generated when the high-frequency output signal uo passes through the R4 flows out of the inverting input end of the operational amplifier to form a negative feedback circuit. According to the invention, the higher harmonic interference of the gyro signal is reduced.