CN103175790B - Double-quartz-crystal-oscillator spectral phonometer and gas detection device employing same - Google Patents
Double-quartz-crystal-oscillator spectral phonometer and gas detection device employing same Download PDFInfo
- Publication number
- CN103175790B CN103175790B CN201310042345.9A CN201310042345A CN103175790B CN 103175790 B CN103175790 B CN 103175790B CN 201310042345 A CN201310042345 A CN 201310042345A CN 103175790 B CN103175790 B CN 103175790B
- Authority
- CN
- China
- Prior art keywords
- double
- quartz
- crystaspectralator
- tuning
- fork type
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Landscapes
- Investigating Or Analysing Materials By Optical Means (AREA)
Abstract
The invention relates to gas sensing technologies and particularly relates to a double-quartz-crystal-oscillator spectral phonometer and a gas detection device employing the same. The gas detection device is used for solving the technical problems of low sensitivity and cumbersomeness in operation of existing gas detection devices. The double-quartz-crystal-oscillator spectral phonometer comprises a gas chamber, wherein the gas chamber is located outside a double-quartz-crystal-oscillator assembly, and the bottom of the gas chamber is provided with a hole; an entrance window and an exit window are respectively formed in a sidewall of the gas chamber along a light path; and the entrance window, the double-quartz-crystal-oscillator assembly and the exit window are located on the same light path. The gas detection device comprises a light source and a light source driver connected with the light source; and a light beam focusing device and the spectral phonometer are sequentially arranged on an exit light path of the light source. The gas detection device further comprises a first phase-locked amplifier and a signal generator which are sequentially connected with each other. According to the spectral phonometer and the gas detection device, through the ingenious arrangement of the double-quartz-crystal-oscillator assembly, the technical problems in current gas detection that the detection sensitivity is low and the frequency of quartz crystal oscillators is required for being measured frequently are solved.
Description
Technical field
The present invention relates to gas sensing techniques, be specially a kind of Double-quartz-crystaspectralator spectrophone and adopt the gas detection apparatus of this acousimeter.
Background technology
Gas molecule is present in the whole space of human lives, with economy, the commecial activity of the mankind, healthy etc. closely bound up.Along with the continuous acceleration of Chinese Industrialization process, the health that have impact on the mankind that the discharge of a large amount of poisonous hazardous gas is serious and existence.Simultaneously in the fields such as oil, chemical industry, space flight, medical science, environment, need the monitoring derivative gas molecule being carried out to high precision high selectivity, to optimize various industrial process.Based on the gas detection technology of molecular spectroscopy because it is highly sensitive, selectivity is good, can the advantage such as on-line real-time measuremen, be subject to people's attention gradually in recent years.Especially optoacoustic spectroscopy, the characteristic be directly proportional to power to optical source wavelength non-selectivity and detection sensitivity with it, is widely used especially.The microphone that Rice Univ USA's laser science group in 2002 takes the lead in using quartz tuning-fork to replace in traditional optoacoustic spectroscopy, detects gas, device volume is reduced greatly, achieve good effect.This device core probe portion is primarily of a tuning-fork type quartz crystal oscillator and two tubule compositions.Fig. 7 is the front elevation of tuning-fork type quartz crystal oscillator, tuning-fork type quartz crystal oscillator has two and raises one's arm, tuning-fork type quartz crystal oscillator is after being subject to external drive, raise one's arm of reciprocating vibration along arrow direction in figure, for convenience of description the upper face vertical with direction of vibration of raising one's arm of tuning-fork type quartz crystal oscillator is called inside and outside vibration plane; The face (face namely paper seen and behind face) parallel with direction of vibration is called the side of raising one's arm of tuning-fork type quartz crystal oscillator; Two raise one's arm between gap be called gap of raising one's arm, as shown in Figure 7 raise one's arm gap direction upwards.Two electrodes are arranged at tuning-fork type quartz crystal oscillator bottom, each connection pin, and a pin is connected with signal ground, and another pin is for exporting the electric signal because vibration produces.Two tubules are placed in tuning-fork type quartz crystal oscillator both sides, pipe axle center all and light path coaxial, form miniature sound cavities, light beam passes through then by second tubule between raising one's arm from two after first tubule, after tested gas absorption luminous energy, because the collision de excitation of gas is sent out, release acoustic energy, acoustic energy accumulates in miniature sound cavities, pass to tuning-fork type quartz crystal oscillator again, tuning-fork type quartz crystal oscillator two is caused to raise one's arm vibration, and then tuning-fork type quartz crystal oscillator is converted into electric signal by piezoelectric effect mechanical vibrational energy, and the intensity of these electric signal is just proportional to the gas concentration be detected.This configuration is called two-tube configuration.Subsequently, for improving its sensitivity further, the physical dimension of two tubules is further optimized.Also have people only to use an independent long tube as sound cavities, opened a slit in the middle part of long tube, long tube is equivalent to be divided into two sections, and only surplus sub-fraction connects; Tuning-fork type quartz crystal oscillator is placed on the side in the middle part of long tube, and long tube slit is relative with the position, gap of tuning-fork type quartz crystal oscillator, to better meet resonant condition, this configuration is called single tube configuration.But current no matter which kind of configures, and how by converting position, the size of resonance lumen and tuning-fork type quartz crystal oscillator, optimized experimental facility, all cannot make detection sensitivity improve further, because detection sensitivity has reached an optimal value under existing device, on the other hand, all there is a weak point in above device, due to the high Q characteristic of tuning-fork type quartz crystal oscillator, (Q refers to the quality factor of quartz crystal oscillator, quality factor=stored energy/each cycle loss of energy, the higher responsive bandwidth of quality factor is narrower), its responsive bandwidth is only had an appointment 2.5Hz, even lower, and its response frequency can along with the change of environmental parameter, such as temperature, humidity, pressure etc. and changing, therefore each when carrying out detection of gas, all must measure its resonant frequency, and then use its resonant frequency (first harmonic detection) or resonant frequency half (second harmonic detection) to modulate its light source, otherwise the sound wave that tuning-fork type quartz crystal oscillator will discharge after can not responding gas absorption luminous energy.This makes current gas detection apparatus operation comparatively loaded down with trivial details, and detection efficiency is lower.
Summary of the invention
The present invention solves that current gas detection apparatus detection sensitivity is not high, the comparatively loaded down with trivial details technical matters of operation, provides a kind of Double-quartz-crystaspectralator spectrophone and adopts the gas detection apparatus of this acousimeter.
Double-quartz-crystaspectralator spectrophone of the present invention realizes by the following technical solutions: a kind of Double-quartz-crystaspectralator spectrophone, comprises a Double-quartz-crystaspectralator assembly; That described Double-quartz-crystaspectralator assembly comprises gap arranged opposite of raising one's arm and have two tuning-fork type quartz crystal oscillators of a fixed gap, the side of raising one's arm of described two tuning-fork type quartz crystal oscillators is parallel to each other; Each tuning-fork type quartz crystal oscillator all has a pin to be connected with signal ground; The pin that each tuning-fork type quartz crystal oscillator is not connected with signal ground is connected with a prime amplifier jointly.
During application, light beam passes from the space between two tuning-fork type quartz crystal oscillators.Double-quartz-crystaspectralator array mode of the present invention is adopted to make use of coupling effect between tuning-fork type quartz crystal oscillator, their response curve is merged, and the impedance between them reduces, and Q value reduces further, and modulation frequency range obviously increases, effectively detection sensitivity can be strengthened.
Further, described Double-quartz-crystaspectralator assembly also comprise one through described tuning-fork type quartz crystal oscillator to the axis in space and tuning-fork type quartz crystal oscillator to the miniature sound cavities of lateral vertical of raising one's arm; Described miniature sound cavities outside middle portion has the slit with the gap parallel alignment of raising one's arm of two tuning-fork type quartz crystal oscillators, among the partial insertion slit of raising one's arm of described two tuning-fork type quartz crystal oscillators.
Tuning-fork type quartz crystal oscillator to insert among slit but does not contact with tube wall.This array mode at tuning-fork type quartz crystal oscillator on the basis of coupling, add miniature sound cavities and tuning-fork type quartz crystal oscillator between coupling, Q value is reduced further, and modulation frequency range also further increases, detection sensitivity obtains further raising.Pipe (miniature sound cavities) is only connected by very narrow part in the part perpendicular with gap direction of raising one's arm.This array mode needs meticulousr machining, because the raise one's arm degree of depth of inserting miniature sound cavities of tuning-fork type quartz crystal oscillator is more shallow, miniature sound cavities and tuning-fork type quartz crystal oscillator between coupling be not very strong, but the center have no occluder of miniature sound cavities, is very easy to carry out beam collimation.
Further, described Double-quartz-crystaspectralator assembly also comprise one through described tuning-fork type quartz crystal oscillator to the axis in space and tuning-fork type quartz crystal oscillator to the miniature sound cavities of lateral vertical of raising one's arm; The both sides that described miniature sound cavities outside middle portion is vertical with gap direction of raising one's arm respectively have a slit, among insertion two slits of raising one's arm all partly of described each tuning-fork type quartz crystal oscillator.
Miniature sound cavities both sides vertical with gap direction of raising one's arm respectively have a slit, and whole pipe only leaves very narrow part in the both sides relative with gap of raising one's arm and connects; Raising one's arm of two tuning-fork type quartz crystal oscillators is inserted in slit, and superposed raising one's arm inserts the slit of top, and the slit of below is inserted in raising one's arm of below, and the coupling part of pipe is positioned among gap of raising one's arm.Tuning-fork type quartz crystal oscillator does not contact with tube wall.This array mode not only possesses all advantages of front a kind of mode, and raises one's arm can insert miniature sound cavities further due to tuning-fork type quartz crystal oscillator, and coupling strengthens further; Simultaneously because raising one's arm from tube center junction of two tuning-fork type quartz crystal oscillators is inserted into miniature sound cavities inside, light beam passes through between must raising one's arm from two, therefore this array mode not only needs meticulous machining, also needs to carry out careful optical alignment.
Further, described Double-quartz-crystaspectralator assembly also comprises the miniature sound cavities be made up of two single tubes that symmetry is located at the axis of the right both sides, space of tuning-fork type quartz crystal oscillator and the right lateral vertical of raising one's arm of tuning-fork type quartz crystal oscillator.
In fact this array mode is equivalent to a pair miniature sound cavities and forms a micro resonant cavity, and two tuning-fork type quartz crystal oscillators are equivalent to the inside entering into micro resonant cavity of part.This array mode does not need meticulous machining, tuning-fork type quartz crystal oscillator is raised one's arm, and to insert the degree of depth of micro resonant cavity very dark, make the Q value of whole system can drop to about 4000 from about 12000 of single sound V shape quartz crystal oscillator, therefore this combination belongs to strong coupling mode, and modulation band-width is also widened further; Because raising one's arm of two tuning-fork type quartz crystal oscillators is inserted into micro resonant cavity inside, light beam must pass through from two gaps of raising one's arm, and therefore this mode needs to carry out careful optical alignment.
Fig. 5 is the comparison diagram of Double-quartz-crystaspectralator assembly and single quartz crystal oscillator component responds curve.Namely described single quartz crystal oscillator assembly refers to parts that classic method adopts and configuration mode thereof.In figure, transverse axis is frequency (Hz), and the longitudinal axis is when external excitation signal, the squared magnitude (arbitrary unit) of single quartz crystal oscillator assembly or Double-quartz-crystaspectralator component responds voltage.S1 is the response curve of single naked tuning-fork type quartz crystal oscillator, and responsive bandwidth only has 2.5Hz; S2 is the response curve that single quartz crystal oscillator adds the micro resonant cavity that is made up of two single tubes, and responsive bandwidth is 3.5Hz; S3 curve is under the third configuration mode mentioned above, the i.e. response curve that obtains of two molecular miniature sound cavities of pipe and the combination of two tuning-fork type quartz crystal oscillators, because two miniature sound cavities and two tuning-fork type quartz crystal oscillators exist strong coupling effect, responsive bandwidth is made to be 7.4Hz, greatly wider than the responsive bandwidth of single quartz crystal oscillator assembly.
Fig. 6 is the comparison diagram of the signal intensity of the water in air that Double-quartz-crystaspectralator assembly and single quartz crystal oscillator assembly are measured under equal experimental situation.In figure, transverse axis is laser current (mA), and ordinate is signal intensity (V).S1 is the signal amplitude that single sound V shape quartz crystal oscillator is measured; S2 is the signal amplitude that single quartz crystal oscillator adds a micro resonant cavity (being made up of two pipes) and measures; S3 is under the third array mode mentioned above, and namely two miniature sound cavities and two tuning-fork type quartz crystal oscillators combine the signal amplitude obtained.As can be seen from the figure, S3 signal is 3 times of S2, and be 46 times of S1, detection sensitivity is significantly improved.
Further, the air chamber that a bottom being positioned at Double-quartz-crystaspectralator component external is provided with hole is also comprised; The sidewall of air chamber is respectively equipped with an incidence window and an exit window along light path; Described incidence window, Double-quartz-crystaspectralator assembly and exit window are positioned in same light path; Described air chamber upper end is provided with gas access near the position of exit window side; The lower end of air chamber is provided with gas vent near the position of incidence window side; Described tuning-fork type quartz crystal oscillator and miniature sound cavities are fixed on the inwall of air chamber by the bearing being located at its underpart; Respective pin on two tuning-fork type quartz crystal oscillators is in parallel to be also connected with signal ground and prime amplifier respectively through behind hole.
When measuring, gas continuous print to be measured flows into air chamber from gas access, and flows out from gas vent, the outgoing after incidence window, Double-quartz-crystaspectralator assembly and exit window of detection light; The acoustic energy Conversion of Energy sending out generation due to the collision de excitation between molecule after gas absorption luminous energy to be measured is corresponding electric signal and inputs to corresponding analytical equipment by prime amplifier to analyze by Double-quartz-crystaspectralator assembly.
Gas detection apparatus of the present invention realizes by the following technical solutions: a kind of gas detection apparatus, the light source drive comprising light source and be connected with light source; Light source emitting light path is provided with beam-focuser and spectrophone in turn; Also comprise the first lock-in amplifier and signal generator that connect in turn; The modulation signal output terminal of signal generator is connected with the modulation port of light source drive; A synchronous signal output end of signal generator is connected with the synchronous signal input end of the first lock-in amplifier; Also comprise data collecting card and computer system; The signal output part of the first lock-in amplifier is connected with data collecting card signal input part; The signal output part of data collecting card is connected with the signal input part of computer system; Described spectrophone adopts Double-quartz-crystaspectralator spectrophone; The signal output part of the prime amplifier of Double-quartz-crystaspectralator spectrophone is connected with the signal input part of the first lock-in amplifier; Described incidence window, Double-quartz-crystaspectralator assembly and exit window are positioned on the emitting light path of beam-focuser in turn.
When detecting trace gas, signal generator is with 1/2nd f
0(f
0for Double-quartz-crystaspectralator element resonant frequency) rate-adaptive pacemaker sinusoidal modulation signal to light source drive, the electric current of light source drive is supplied to light source by after described sinusoidal modulation signal modulation, wavelength-modulated is carried out to output light, the light that light source sends is after Double-quartz-crystaspectralator spectrophone, Double-quartz-crystaspectralator assembly converts the vibration received to corresponding electric signal and this electric signal is passed to prime amplifier, prime amplifier is transferred to the first lock-in amplifier after being amplified by this electric signal, the first lock-in amplifier synchronizing signal that acknowledge(ment) signal generator is sent here simultaneously carries out second harmonic demodulation to photo detector signal, the electric signal including gas concentration information to be measured demodulated is gathered by data collecting card, the signal collected is inputed to computer system by data collecting card, computer system converts the signal received to corresponding image and shows under the support of corresponding software, the concentration of gas to be measured directly can read from image, described corresponding software is the known technology of those skilled in the art, is easy to write.When measuring certain gas, should be demarcated measurement mechanism by this kind of gas of concentration known in advance, calibrated device just can be measured this kind of gas.Described scaling method is technology known in those skilled in the art.
Further, also comprise and be positioned at gas reference pond to be measured on Double-quartz-crystaspectralator spectrophone emitting light path and photodetector in turn; Photodetector is connected with second lock-in amplifier by signal output part, and described second lock-in amplifier is connected with photodetector by signal input part; Another synchronous signal output end of signal generator is connected with the synchronous signal input end of the second lock-in amplifier, and the signal output part of the second lock-in amplifier is connected with another signal input part of data collecting card; The signal output part of computer system is connected with the modulation port of light source drive.
Gas reference pond to be measured, the second lock-in amplifier, data collecting card and computer system constitute feedback system of the present invention jointly.The gas identical with gas componant to be measured is filled with in gas reference pond to be measured, by air chamber outgoing light through gas reference pond laggard enter photodetector, photodetector converts the light signal of acceptance to corresponding electric signal, then the second lock-in amplifier is given, the second lock-in amplifier synchronizing signal that acknowledge(ment) signal generator is sent here simultaneously carries out third harmonic demodulation to photo detector signal, obtain frequency discrimination signal, frequency discrimination signal is gathered by data collecting card, PID signal is carried out regular by computer system, and the output current of light source drive is adjusted according to frequency discrimination signal, controlling laser wavelength by light source drive remains on the tested Absorption Line of gas to be measured, the detection optical wavelength that light source exports is higher than the Absorption Line (namely during absorption frequency) of gas to be measured, and the electric current reducing light source drive makes the wavelength of detection light reduce, when detecting Absorption Line lower than gas to be measured of the wavelength of light, the electric current raising light source drive makes the wavelength of detection light raise, the detection optical wavelength that adjustment light source exports so in real time remains on the Absorption Line of gas to be measured.The optical wavelength that light source is launched can be locked on the tested Absorption Line of gas to be measured by the introducing of feedback system, and avoiding light source in the past constantly must carry out according to frequency range the process that scans from low to high, effectively improves detection efficiency.
The present invention's prime amplifier used, lock-in amplifier, signal generator are the common instrument of this area, have Multiple Type available; The regular method commonly used for those skilled in the art of described PID signal.
The invention has the beneficial effects as follows: one, use Double-quartz-crystaspectralator assembly to detect object gas, broken current single quartz crystal oscillator and carried out detecting the bottleneck being difficult to promote sensitivity further to object gas; Two, the use of Double-quartz-crystaspectralator assembly is not the simple Overlay of signal, but by tuning-fork type quartz crystal oscillator between and coupling effect between tuning-fork type quartz crystal oscillator pair and miniature sound cavities, make the impedance between them very little, energy can exchange between which, cause Double-quartz-crystaspectralator spectrophone quality factor q to reduce, but signal strengthen on the contrary; Three, when resonant frequency is almost constant, the reduction of quality factor q makes bandwidth increase further, like this, Double-quartz-crystaspectralator spectrophone can be used in very wide modulation frequency range, avoids the technical requirement frequently must measuring its resonant frequency when single quartz crystal oscillator detects object gas; Four, the introducing of gas reference pond to be measured and feedback system enables optical maser wavelength rest on the position of tested Absorption Line all the time, and without the need to being carried out periodic scan by survey line, improves detection efficiency; Five, the position of gas access and gas vent arranges and can ensure that tested gas enters from one end of miniature sound cavities, and bring out from another of miniature sound cavities, such gas can be full of rapidly miniature sound cavities, reaches quick testing goal.
Accompanying drawing explanation
Fig. 1 is a kind of structure of Double-quartz-crystaspectralator assembly of the present invention when specifically implementing and pin connection diagram.
Fig. 2 is the second structure of Double-quartz-crystaspectralator assembly of the present invention when specifically implementing and pin connection diagram.
Fig. 3 is the third structure when specifically implementing of Double-quartz-crystaspectralator assembly of the present invention and pin connection diagram.
Fig. 4 is gas detection apparatus structural representation of the present invention.
Fig. 5 contrasts schematic diagram for adopting the response curve of Double-quartz-crystaspectralator assembly and single quartz crystal oscillator assembly described in Fig. 3.
Fig. 6 measures the Comparative result figure after water in air vapour for adopting Double-quartz-crystaspectralator assembly and single quartz crystal oscillator assembly described in Fig. 3 under equal experimental situation.
The main TV structure schematic diagram of Fig. 7 tuning-fork type quartz crystal oscillator.
1-light source, 2-beam-focuser, 3-spectrophone, 4-plane mirror, 5-concave mirror, 6-gas reference pond to be measured, 7-photodetector, 8-prime amplifier, 9-electro-magnetic shielding cover, 10-signal generator, 11-first lock-in amplifier, 12-computer system, 13-data collecting card, 14-second lock-in amplifier, 15-light source drive, 31-incidence window, 32-exit window, the miniature sound cavities of 33-, 34-gas vent, 35-gas access, 36-tuning-fork type quartz crystal oscillator, 37-Double-quartz-crystaspectralator assembly, 38-air chamber, 331-slit, 61-first incidence window, 62-first exit window.
Embodiment
A kind of Double-quartz-crystaspectralator spectrophone, comprises a Double-quartz-crystaspectralator assembly 37; That described Double-quartz-crystaspectralator assembly 37 comprises gap arranged opposite of raising one's arm and have two tuning-fork type quartz crystal oscillators 36 of a fixed gap, the side of raising one's arm of described two tuning-fork type quartz crystal oscillators 36 is parallel to each other; Each tuning-fork type quartz crystal oscillator 36 all has a pin to be connected with signal ground; The pin that each tuning-fork type quartz crystal oscillator 36 is not connected with signal ground is connected with a prime amplifier 8 jointly.
Described Double-quartz-crystaspectralator assembly 37 also comprise one through described tuning-fork type quartz crystal oscillator to the axis in space and tuning-fork type quartz crystal oscillator to the miniature sound cavities 33 of lateral vertical of raising one's arm; Described miniature sound cavities 33 outside middle portion has the slit 331 with the gap parallel alignment of raising one's arm of two tuning-fork type quartz crystal oscillators 36, among the partial insertion slit 331 of raising one's arm of described two tuning-fork type quartz crystal oscillators 36.As shown in Figure 1.
Described Double-quartz-crystaspectralator assembly 37 also comprise one through described tuning-fork type quartz crystal oscillator to the axis in space and tuning-fork type quartz crystal oscillator to the miniature sound cavities 33 of lateral vertical of raising one's arm; The both sides that described miniature sound cavities 33 outside middle portion is vertical with gap direction of raising one's arm respectively have a slit 331, among insertion two slits of raising one's arm all partly of described each tuning-fork type quartz crystal oscillator 36.As shown in Figure 2.
Described Double-quartz-crystaspectralator assembly 37 also comprises the miniature sound cavities 33 be made up of two single tubes that symmetry is located at the axis of the right both sides, space of tuning-fork type quartz crystal oscillator and the right lateral vertical of raising one's arm of tuning-fork type quartz crystal oscillator.As shown in Figure 3.
Also comprise the air chamber 38 that a bottom being positioned at Double-quartz-crystaspectralator assembly 37 outside is provided with hole; The sidewall of air chamber 38 is respectively equipped with an incidence window 31 and an exit window 32 along light path; Described incidence window 31, Double-quartz-crystaspectralator assembly 37 and exit window 32 are positioned in same light path; Described air chamber 38 upper end is provided with gas access 35 near the position of exit window 32 side; The lower end of air chamber 38 is provided with gas vent 34 near the position of incidence window 31 side; Described tuning-fork type quartz crystal oscillator 36 and miniature sound cavities 33 are fixed on the inwall of air chamber 38 by the bearing being located at its underpart; Respective pin on two tuning-fork type quartz crystal oscillators 36 is in parallel to be also connected with signal ground and prime amplifier 8 respectively through behind hole.
A kind of gas detection apparatus, the light source drive 15 comprising light source 1 and be connected with light source 1; Light source 1 emitting light path is provided with in turn beam-focuser 2 and spectrophone 3; Also comprise the first lock-in amplifier 11 and signal generator 10 that connect in turn; The modulation signal output terminal of signal generator 10 is connected with the modulation port of light source drive 15; A synchronous signal output end of signal generator 10 is connected with the synchronous signal input end of the first lock-in amplifier 11; Also comprise data collecting card 13 and computer system 12; The signal output part of the first lock-in amplifier 11 is connected with a signal input part of data collecting card 13; The signal output part of data collecting card 13 is connected with the signal input part of computer system 12; Described spectrophone 3 adopts Double-quartz-crystaspectralator spectrophone; The signal output part of the prime amplifier 8 of Double-quartz-crystaspectralator spectrophone is connected with the signal input part of the first lock-in amplifier 11; Described incidence window 31, Double-quartz-crystaspectralator assembly 37 and exit window 32 are positioned on the emitting light path of beam-focuser 2 in turn.
Also comprise and be positioned at gas reference pond 6 to be measured on Double-quartz-crystaspectralator spectrophone 3 emitting light path and photodetector 7 in turn; Photodetector 7 is connected with second lock-in amplifier 14 by signal output part, and described second lock-in amplifier 14 is connected with photodetector 7 by signal input part; Another synchronous signal output end of signal generator 10 is connected with the synchronous signal input end of the second lock-in amplifier 14, and the signal output part of the second lock-in amplifier 14 is connected with another signal input part of data collecting card 13; The signal output part of computer system 12 is connected with the modulation port of light source drive 15.
The emitting light path of described Double-quartz-crystaspectralator spectrophone 3 is provided with plane mirror 4, described plane mirror 4 is 45 ° with the emitting light path angulation of Double-quartz-crystaspectralator spectrophone 3, and the reflected light path of plane mirror 4 is provided with a concave mirror 5; Described concave mirror 5 is 45 ° with the emitting light path angulation of plane mirror 4, and the emitting light path of described concave mirror 5 is contrary with the emitting light path direction of Double-quartz-crystaspectralator spectrophone 3; Described gas reference pond 6 to be measured is positioned on the emitting light path of concave mirror 5.
The incidence window 31 of described Double-quartz-crystaspectralator spectrophone 3 and exit window 32 are all non-perpendicular with light path, and described incidence window 31 plane of incidence and light path angulation are 75 ° ~ 85 ° (can select 75 °, 80 °, 85 °); The exit facet of described exit window 32 and the reverse extending line angulation of light path are 75 ° ~ 85 ° (can select 75 °, 80 °, 85 °).
The outside of described prime amplifier 8 is provided with an electro-magnetic shielding cover 9.
The incidence window 31 of Double-quartz-crystaspectralator spectrophone 3 and exit window 32 are all non-perpendicular with light path, avoid light beam feedback, have effectively suppressed the appearance of interference fringe; Electro-magnetic shielding cover 9 effectively can shield electromagnetic noise, avoids introducing outside noise interference; Electro-magnetic shielding cover 9 is generally made by foreign copper-nickel alloy; Electro-magnetic shielding cover 9 connects signal ground, and prime amplifier 8 is placed on and is less than in the scope of 10cm from Double-quartz-crystaspectralator spectrophone 3.
Plane mirror 4 and concave mirror 5 form 180 degree of light paths upset subassembly, can make light path folding, effectively utilize space, the volume of gas detection apparatus is reduced greatly; The use of concave mirror 5 makes light beam having slight converging action by during gas reference pond 6 to be measured, not only avoid the possibility that the photodetector 7 that uses lens to bring is saturated, it also avoid the shortcoming that photodetector 7 signal that free light beam brings is weak.Light beam enters gas reference pond 6 to be measured by the first incidence window 61, by the first exit window 62 outgoing.First incidence window 61 exit facet becomes 75 ° of angles with light path, the first exit window 62 exit facet and light path angulation are 75 °.
Light source 1 can adopt near infrared Distributed Feedback Laser, in infrared QCL laser instrument, or the accurate lasing light emitter of the LD in broadband, LED.
During embody rule, signal generator 10 is with Double-quartz-crystaspectralator spectrophone 3 resonant frequency f
0frequency values (f) sine wave output of half, modulated by light source drive 15 pairs of light sources 1, modulated light is by behind gas reference pond 6 to be measured, be converted to corresponding electric signal by photodetector 7 and give the second lock-in amplifier 14, gathered by data collecting card 13 after second lock-in amplifier 14 demodulates 3f signal, giving computer system 12, to carry out PID regular, then delivers to light source drive 15 pairs of laser currents and compensate, optical maser wavelength is rested on tested gaseous absorption line all the time.And the tested gas signal that Double-quartz-crystaspectralator spectrophone 3 detects gives the first lock-in amplifier 11 after being amplified by prime amplifier 8, demodulate 2f signal, gathered by data collecting card 13, give computer system 12 and show.
Three kinds of specific embodiments are introduced: as shown in Figure 1, miniature sound cavities is a pipe to embodiment 1, beats slit in two sides, and the width of slit is between 0.35mm-1mm, and tuning-fork type quartz crystal oscillator is inserted into below in conjunction with accompanying drawing.This mode needs meticulousr machining, and because quartz crystal oscillator is raised one's arm, to insert the degree of depth of micro resonant cavity more shallow, and coupling is not very strong, but the center have no occluder of miniature sound cavities, be very easy to carry out beam collimation.
Embodiment 2 as shown in Figure 2, miniature sound cavities remains a pipe (the same with the pipe of the first), slit is beaten at the upper and lower surface of pipe, the width of slit is between 0.35mm-1mm, tuning-fork type quartz crystal oscillator is inserted from pipe junction respectively, the width of pipe intermediate connections be less than two of tuning fork raise one's arm between distance (<0.3mm).This mode not only possesses all advantages of first kind of way, and raise one's arm can insert miniature sound cavities further due to tuning-fork type quartz crystal oscillator, coupling strengthens further, because raising one's arm from tube center junction of two tuning-fork type quartz crystal oscillators is inserted into micro resonant cavity inside, light beam passes through between must raising one's arm from two, therefore this mode not only needs meticulous machining, also needs to carry out careful optical alignment.
As shown in Figure 3, micro resonant cavity is made up of two stainless steel tubules embodiment 3, and two tuning-fork type quartz crystal oscillators insert between two pipes relatively, and the spacing of two tuning-fork type quartz crystal oscillator end faces is between 0.1mm-1mm.This mode is the equal of that two discrete stainless steel tubules form a micro resonant cavity, therefore meticulous machining is not needed, tuning-fork type quartz crystal oscillator is raised one's arm, and to insert the degree of depth of micro resonant cavity very dark, make the Q value of whole system can drop to about 4000 from about 12000 of single sound V shape quartz crystal oscillator, therefore thisly strong coupling mode is belonged to, modulation band-width is widened further, because raising one's arm of two tuning-fork type quartz crystal oscillators is inserted into micro resonant cavity inside, light beam passes through between must raising one's arm from two, therefore this mode needs to carry out careful optical alignment.During application, miniature Acoustic resonance cavity length is between 5mm-15mm, and internal diameter is between 0.4mm-1.2mm, and external diameter is between 0.7mm-2mm; The resonant frequency of tuning-fork type quartz crystal oscillator 36 is 32.768kHz.
Claims (10)
1. a Double-quartz-crystaspectralator spectrophone, is characterized in that comprising a Double-quartz-crystaspectralator assembly (37); That described Double-quartz-crystaspectralator assembly (37) comprises gap arranged opposite of raising one's arm and have two tuning-fork type quartz crystal oscillators (36) of a fixed gap, the size in space is between 0.1mm-1mm; The side of raising one's arm of described two tuning-fork type quartz crystal oscillators (36) is parallel to each other; Each tuning-fork type quartz crystal oscillator (36) all has a pin to be connected with signal ground; The pin that each tuning-fork type quartz crystal oscillator (36) is not connected with signal ground is connected with a prime amplifier (8) jointly.
2. Double-quartz-crystaspectralator spectrophone as claimed in claim 1, it is characterized in that described Double-quartz-crystaspectralator assembly (37) also comprise one through described tuning-fork type quartz crystal oscillator to the axis in space and tuning-fork type quartz crystal oscillator to the miniature sound cavities (33) of lateral vertical of raising one's arm; Described miniature sound cavities (33) outside middle portion has the slit (331) with the gap parallel alignment of raising one's arm of two tuning-fork type quartz crystal oscillators (36), among the partial insertion slit (331) of raising one's arm of described two tuning-fork type quartz crystal oscillators (36); The width of slit (331) is between 0.35mm-1mm.
3. Double-quartz-crystaspectralator spectrophone as claimed in claim 1, it is characterized in that described Double-quartz-crystaspectralator assembly (37) also comprise one through described tuning-fork type quartz crystal oscillator to the axis in space and tuning-fork type quartz crystal oscillator to the miniature sound cavities (33) of lateral vertical of raising one's arm; The both sides that described miniature sound cavities (33) outside middle portion is vertical with gap direction of raising one's arm respectively have a slit (331), among insertion two slits of raising one's arm all partly of described each tuning-fork type quartz crystal oscillator (36); The width of slit (331) is between 0.35mm-1mm.
4. Double-quartz-crystaspectralator spectrophone as claimed in claim 1, it is characterized in that described Double-quartz-crystaspectralator assembly (37) also comprises the miniature sound cavities (33) be made up of two single tubes that symmetry is located at the axis of the right both sides, space of tuning-fork type quartz crystal oscillator and the right lateral vertical of raising one's arm of tuning-fork type quartz crystal oscillator, miniature sound cavities (33) length is between 5mm-15mm, internal diameter is between 0.4mm-1.2mm, and external diameter is between 0.7mm-2mm.
5. the Double-quartz-crystaspectralator spectrophone according to any one of claim 2 ~ 4, characterized by further comprising one and is positioned at the air chamber (38) that the outside bottom of Double-quartz-crystaspectralator assembly (37) is provided with hole; The sidewall of air chamber (38) is respectively equipped with an incidence window (31) and an exit window (32) along light path; Described incidence window (31), Double-quartz-crystaspectralator assembly (37) and exit window (32) are positioned in same light path; Described air chamber (38) upper end is provided with gas access (35) near the position of exit window (32) side; The lower end of air chamber (38) is provided with gas vent (34) near the position of incidence window (31) side; Described tuning-fork type quartz crystal oscillator (36) and miniature sound cavities (33) are fixed on the inwall of air chamber (38) by the bearing being located at the two bottom respectively; Respective pin on two tuning-fork type quartz crystal oscillators (36) is in parallel to be also connected with signal ground and prime amplifier (8) respectively through behind hole.
6. a gas detection apparatus, the light source drive (15) comprising light source (1) and be connected with light source (1); Light source (1) emitting light path is provided with in turn beam-focuser (2) and spectrophone (3); Also comprise the first lock-in amplifier (11) and signal generator (10) that connect in turn; The modulation signal output terminal of signal generator (10) is connected with the modulation port of light source drive (15); A synchronous signal output end of signal generator (10) is connected with the synchronous signal input end of the first lock-in amplifier (11); Also comprise data collecting card (13) and computer system (12); The signal output part of the first lock-in amplifier (11) is connected with a signal input part of data collecting card (13); The signal output part of data collecting card (13) is connected with the signal input part of computer system (12); It is characterized in that described spectrophone (3) adopts Double-quartz-crystaspectralator spectrophone as claimed in claim 5; The signal output part of the prime amplifier (8) of Double-quartz-crystaspectralator spectrophone is connected with the signal input part of the first lock-in amplifier (11); Described incidence window (31), Double-quartz-crystaspectralator assembly (37) and exit window (32) are positioned on the emitting light path of beam-focuser (2) in turn.
7. gas detection apparatus as claimed in claim 6, is characterized in that, also comprises and is positioned at gas reference pond (6) to be measured on Double-quartz-crystaspectralator spectrophone (3) emitting light path and photodetector (7) in turn; Photodetector (7) is connected with second lock-in amplifier (14) by signal output part, and described second lock-in amplifier (14) is connected with photodetector (7) by signal input part; Another synchronous signal output end of signal generator (10) is connected with the synchronous signal input end of the second lock-in amplifier (14), and the signal output part of the second lock-in amplifier (14) is connected with another signal input part of data collecting card (13); The signal output part of computer system (12) is connected with the modulation port of light source drive (15).
8. gas detection apparatus as claimed in claim 7, it is characterized in that, the emitting light path of described Double-quartz-crystaspectralator spectrophone (3) is provided with plane mirror (4), described plane mirror (4) is 45 ° with the emitting light path angulation of Double-quartz-crystaspectralator spectrophone (3), and the reflected light path of plane mirror (4) is provided with a concave mirror (5); Described concave mirror (5) is 45 ° with the emitting light path angulation of plane mirror (4), and the emitting light path of described concave mirror (5) is contrary with the emitting light path direction of Double-quartz-crystaspectralator spectrophone (3); Described gas reference pond (6) to be measured is positioned on the emitting light path of concave mirror (5).
9. the gas detection apparatus according to any one of claim 6 ~ 8, it is characterized in that, incidence window (31) and the exit window (32) of described Double-quartz-crystaspectralator spectrophone (3) are all non-perpendicular with light path, and described incidence window (31) plane of incidence and light path angulation are 75 ° ~ 85 °; Exit facet and the light path reverse extending line angulation of described exit window (32) are 75 ° ~ 85 °.
10. the gas detection apparatus according to any one of claim 6 ~ 8, is characterized in that, the outside of described prime amplifier (8) is provided with an electro-magnetic shielding cover (9).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310042345.9A CN103175790B (en) | 2013-02-04 | 2013-02-04 | Double-quartz-crystal-oscillator spectral phonometer and gas detection device employing same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310042345.9A CN103175790B (en) | 2013-02-04 | 2013-02-04 | Double-quartz-crystal-oscillator spectral phonometer and gas detection device employing same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN103175790A CN103175790A (en) | 2013-06-26 |
| CN103175790B true CN103175790B (en) | 2015-05-13 |
Family
ID=48635796
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201310042345.9A Active CN103175790B (en) | 2013-02-04 | 2013-02-04 | Double-quartz-crystal-oscillator spectral phonometer and gas detection device employing same |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN103175790B (en) |
Families Citing this family (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103792195B (en) * | 2014-01-15 | 2016-05-11 | 山西大学 | Two light path optoacoustic spectroscopy detecting modules and adopt the gas concentration detector of this module |
| CN103837226B (en) * | 2014-03-17 | 2016-01-20 | 山西大学 | Dual resonant cavity optoacoustic spectroscopy acousimeter and adopt the gas detection apparatus of this acousimeter |
| CN104280340B (en) * | 2014-10-28 | 2016-08-03 | 山西大学 | The gas detection apparatus based on LED light source and using electricity modulation phase resolving therapy and method |
| CN104697934A (en) * | 2015-03-20 | 2015-06-10 | 山东大学 | Gas concentration measuring method of quartz tuning fork double-beam system |
| CN105258713B (en) * | 2015-11-17 | 2017-06-16 | 哈尔滨工业大学 | A kind of quartz crystal oscillator sensor of use low temperature glass solder welding and preparation method thereof |
| CN105651374B (en) * | 2016-01-27 | 2019-04-05 | 山西大学 | The coaxial optoacoustic spectroscopy acousimeter of single tube and the gas detection apparatus for using the acousimeter |
| CN106596411A (en) * | 2016-12-16 | 2017-04-26 | 苏州亿科斯通电气有限公司 | Auxiliary assembly apparatus and method of quartz-reinforced photoacoustic spectral sounder |
| WO2019014134A1 (en) * | 2017-07-11 | 2019-01-17 | Saudi Arabian Oil Company | Photoacoustic gas detection |
| CN108593763B (en) * | 2018-03-26 | 2021-03-30 | 山东大学 | Real-time detection device for multi-component gas based on quartz tuning fork frequency division demodulation |
| CN108732105A (en) * | 2018-07-10 | 2018-11-02 | 南昌航空大学 | Distributed gas detection device based on fast travelling waves of optical fibre and method |
| CN109975214B (en) * | 2019-04-03 | 2021-04-23 | 哈尔滨工业大学 | Gas concentration detection device and method for quartz photoacoustic spectroscopy |
| CN113340847B (en) * | 2021-06-17 | 2024-03-12 | 山西大学 | Phi-type quartz tuning fork and trace gas detection device based on phi-type quartz tuning fork |
| CN114397246A (en) * | 2022-01-24 | 2022-04-26 | 暨南大学 | Clamp type crystal oscillator for photoacoustic spectrum detection and gas detection device thereof |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2006060032A2 (en) * | 2004-05-10 | 2006-06-08 | Arizona Board Of Regents | Chemical and biological sensing using tuning forks |
| US7245380B2 (en) * | 2002-06-10 | 2007-07-17 | William Marsh Rice University | Quartz-enhanced photoacoustic spectroscopy |
| CN101358918A (en) * | 2007-07-24 | 2009-02-04 | Ir微系统股份有限公司 | Method and gas sensor for performing quartz-enhanced photoacoustic spectroscopy |
| CN101535801A (en) * | 2006-11-10 | 2009-09-16 | 皇家飞利浦电子股份有限公司 | Oscillator element for photo acoustic detector |
| CN102713565A (en) * | 2009-09-30 | 2012-10-03 | 康宁股份有限公司 | Gas sensor based on photoacoustic detection |
-
2013
- 2013-02-04 CN CN201310042345.9A patent/CN103175790B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7245380B2 (en) * | 2002-06-10 | 2007-07-17 | William Marsh Rice University | Quartz-enhanced photoacoustic spectroscopy |
| WO2006060032A2 (en) * | 2004-05-10 | 2006-06-08 | Arizona Board Of Regents | Chemical and biological sensing using tuning forks |
| CN101535801A (en) * | 2006-11-10 | 2009-09-16 | 皇家飞利浦电子股份有限公司 | Oscillator element for photo acoustic detector |
| CN101358918A (en) * | 2007-07-24 | 2009-02-04 | Ir微系统股份有限公司 | Method and gas sensor for performing quartz-enhanced photoacoustic spectroscopy |
| US7605922B2 (en) * | 2007-07-24 | 2009-10-20 | Ir Microsystems Sa | Method and gas sensor for performing quartz-enhanced photoacoustic spectroscopy |
| CN102713565A (en) * | 2009-09-30 | 2012-10-03 | 康宁股份有限公司 | Gas sensor based on photoacoustic detection |
Non-Patent Citations (3)
| Title |
|---|
| NO trace gas sensor based on quartz-enhanced photoacoustic spectroscopy and external cavity quantum cascade laser;V. Spagnolo et al.;《Appl Phys B》;20100331;第100卷;2 experimental details，附图1 * |
| 王贵师 等.基于石英音叉增强型光谱技术(QEPAS)的实时探测系统研究.《物理学报》.2012,第61卷(第12期),第1-8页. * |
| 石英增强光声光谱在氢气纯度分析中的应用;董磊 等;《大气与环境光学学报》;20121130;第7卷(第6期);第422页右栏第1段，图1 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN103175790A (en) | 2013-06-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103175790B (en) | Double-quartz-crystal-oscillator spectral phonometer and gas detection device employing same | |
| CN103175791B (en) | Multi-quartz-crystal-oscillator spectral phonometer and gas detection device employing same | |
| CN107064012B (en) | Quartz enhanced photoacoustic spectroscopy gas-detecting device and method based on beat effect | |
| CN104237135B (en) | CO gas detecting systems and method based on quartz tuning fork strengthened optoacoustic spectroscopy | |
| CN105651374B (en) | The coaxial optoacoustic spectroscopy acousimeter of single tube and the gas detection apparatus for using the acousimeter | |
| CN105277503B (en) | Multicomponent gas while detection means and method based on two amounts son cascade laser spectrum | |
| CN110346296A (en) | A kind of multi-cavity type is partly begun to speak resonance light sound pond and multiple gases measuring system simultaneously | |
| CN102288306B (en) | Method for simultaneously measuring output single-pulse energy and waveforms of lasers | |
| US9671325B2 (en) | Particle measuring device | |
| CN104251819A (en) | Photoacoustic spectrometry gas detection apparatus based on infrared light source | |
| CN103063574A (en) | Membrane-type minitype photoacoustic cell and application thereof | |
| US10876958B2 (en) | Gas-detecting device with very high sensitivity based on a Helmholtz resonator | |
| CN103149681B (en) | Tuning fork type photo-chopper and trace gas measuring device using tuning fork type photo-chopper | |
| CN103792195A (en) | Double-optical-path photoacoustic spectrometry detection module and gas concentration detector by adopting module | |
| CN103411898B (en) | All-optical gas detection method and device based on quartz enhanced photoacoustic spectrum | |
| CN113295620B (en) | Optical fiber coupled all-solid-state enhanced photoacoustic spectroscopy gas photoacoustic detection module and method | |
| CN107884344A (en) | A kind of optoacoustic spectroscopy gas sensing system of the active air chamber based on semiconductor laser | |
| CN202770761U (en) | Device for measuring concentration of trace gas | |
| CN103389270A (en) | Apparatus for measuring concentration of trace gas, and method thereof | |
| CN106290165A (en) | General frequency strengthens optoacoustic spectroscopy acousimeter and uses the gas detection apparatus of this acousimeter | |
| CN209311319U (en) | Quartz tuning fork photoacoustic spectrum sensor | |
| CN110361360A (en) | Tunable laser half-wave scan control method and system for gas detection | |
| CN102879355A (en) | Device for monitoring methane gas concentration by multimode diode laser absorption spectroscopy technology and monitoring method | |
| CN113281262A (en) | All-fiber double-gas synchronous detection photoacoustic spectroscopy system based on passive tuning fork and detection method thereof | |
| CN106802278A (en) | Quartz enhanced photoacoustic spectroscopy acousimeter and gas detection apparatus that double wave abdomen is excited |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |