CN203148838U - Trace moisture detection device taking internal water of optical fiber gas sensor device as reference - Google Patents
Trace moisture detection device taking internal water of optical fiber gas sensor device as reference Download PDFInfo
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- CN203148838U CN203148838U CN 201320093238 CN201320093238U CN203148838U CN 203148838 U CN203148838 U CN 203148838U CN 201320093238 CN201320093238 CN 201320093238 CN 201320093238 U CN201320093238 U CN 201320093238U CN 203148838 U CN203148838 U CN 203148838U
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- optical fiber
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- differential amplifier
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Abstract
The utility model relates to a trace moisture detection device taking internal water of an optical fiber gas sensor device as reference, belonging to the technical field of optical fiber detection. The device comprises a calibration system, a DFB (Distributed Feed Back) laser, an air chamber, a PIN photoelectric detector and a singlechip, wherein the calibration system is used for calibrating water content inside a device; the DFB laser is positioned in front of the air chamber; an optical collimator is positioned inside the air chamber; the PIN photoelectric detector is positioned behind the optical collimator; the output end of the PIN photoelectric detector is connected with one input end of a differential amplification circuit; the output end of the differential amplification circuit is connected with a filter circuit; the output end of the filter circuit is connected with an A/D (Analog-to-Digital) acquisition port of the singlechip; the singlechip is connected with the DFB laser so as to supply a driving current to the DFB laser; and the singlechip is connected with one input end of the differential amplification circuit so as to provide input signals for the input end of the differential amplification circuit. The device has the advantages of electromagnetic radiation resistance, corrosion resistance and simple techniques, and is convenient to carry over, stable in performance and low in manufacturing cost in use.
Description
Technical field
It is the trace aqueous vapor pick-up unit of reference with fiber gas sensor device inside water that the utility model relates to a kind of, belongs to optics aqueous vapor detection technique field.
Background technology
Pure SF
6Gas is a kind of colorless and odorless, avirulent gas, can not burn, stable chemical performance, do not produce chemical reaction with other materials at normal temperatures, have the characteristic of not firing, be better than insulating oil, thereby have good insulation performance characteristic and arc quenching characteristic, under normal operation, be comparatively desirable insulating medium.The SF6 on-load switch is a kind of good on-load switch realized of many users in recent years, it is long to remove electric life, the strong grade of the power of cut-offfing has outside the common advantage with vacuum load switch, its outstanding advantage is to realize three working positions (connection, disconnection and ground connection) easily, little electric current (inductance, electric capacity) cut-offs, and anti-harsh and unforgiving environments condition ability is strong.Suit to apply at the town and country medium voltage distribution network.But the SF in operation
6In the switchgear, because SF
6Reason such as prepare or equipment sealing is bad impure, may contain moisture, the existence of moisture can seriously jeopardize the safe and reliable operation of electrical equipment.Therefore to SF
6In detection and the control of aqueous vapor concentration require relatively stricter.
At present, the measuring instrument that adopts in China's electric system mainly contains dew point method, capacitance-resistance method and electrolytic process.Dew point hygrometer is simple to operate, can measure at normal pressure and being higher than under the normal pressure, but very easily be subjected to the influence of various disturbing factors; The resistance-capacitance type hygronom is subject to the influence of detected temperatures and detected pressures in actual applications; Before the shortcoming of electrolytic process was in-site measurement, measuring system itself was also moist, and background values is often arranged, and this makes measurement result accurate inadequately, and it can not realize on-line measurement.
In addition fiber gas sensor because of its good stability, measuring accuracy height, anti-electromagnetic interference (EMI), online detection, can realize not having advantages such as electro-detection and in the measurement of trace gas concentration, obtain more and more widely application, and bringing into play irreplaceable effect at the special occasions such as storage of some flammable explosive gas.. when light when the aqueous vapor medium, laser and hydrone interact, and produce absorption effect at the absorption peak of corresponding water, can describe I with Beer-Lambert law
t(λ)=I
0(λ) exp[-α (λ) CL)], I wherein
t(λ) be the light intensity after the decay of transmission distance L, I
0(λ) be incident intensity, α (λ) is the absorption coefficient under the corresponding wavelength, can find at database HITRAN2008.Then as the concentration C of aqueous vapor C=ln[I when not being big especially
0(λ)/I
t(λ)]/[α (λ) L] ≈ [1-I
t(λ)/I
0(λ)] // [α (λ) L].Can draw absorptivity [1-I
t(λ)/I
0(λ)] be directly proportional with the concentration C of aqueous vapor in the gas.People's such as Chang Jun, Wang Zongliang, Wang Wei outstanding person, Song Fujun utility model patent " a kind of little water pick-up unit based on scanning method " is exactly a kind of like this gas sensor for the detection of trace aqueous vapor of introducing.But the water in the fiber gas sensor device inside does not obtain considering at this trace aqueous vapor pick-up unit.
Usually in the design of fiber gas sensor, Distributed Feedback Laser is because its monochromaticity is good, the advantage of line width, power stability is widely used as light source; Optical fiber collimator is used for collimation laser, and gas enters into the inside of optical fiber collimator by the pore of collimating apparatus encapsulation simultaneously, with laser interaction; The advantage that the PIN photodetector is little because of its volume, coupling efficiency is high is often used as electrooptical device.Distributed Feedback Laser, optical fiber collimator and PIN photodetector are requisite devices in the fiber gas sensor structure, the slit that in their encapsulating structure, all has certain width because of the needs of its principle of work, and their production is all finished under indoor conditions, has charged into the air that certain liquid water content is arranged in the slit inevitably.
The light path of Fibre Optical Sensor is passed the air in these three devices, the water of device inside causes absorption to the light at the corresponding absorption peak of water absorption peak in laser place, if the absorption that causes at this background water is not carried out corresponding signal processing or carried out the innovation of detection technique, testing result will inevitably be affected.Air in the device completely cuts off with the air in the external world simultaneously, and the content of device inside water is metastable like this.
Summary of the invention
In order to overcome defective and the deficiency that prior art exists, the utility model proposes a kind of is the trace aqueous vapor pick-up unit of reference with fiber gas sensor device inside water, aims to provide easy to use, stable performance, trace aqueous vapor pick-up unit that cost is low.
The technical solution of the utility model realizes in the following manner:
A kind of is the trace aqueous vapor pick-up unit of reference with fiber gas sensor device inside water, comprise calibration system, Distributed Feedback Laser, air chamber, optical fiber collimator, PIN photodetector, differential amplifier circuit, filtering circuit and single-chip microcomputer, before it is characterized in that Distributed Feedback Laser is positioned at air chamber, optical fiber collimator is positioned at air chamber, and the PIN photodetector is positioned at after the optical fiber collimator; Optical fiber collimator is coupled on the PIN photodetector through the single-mode fiber connection, PIN photodetector output terminal connects an input end of differential amplifier circuit, the output terminal of differential amplifier circuit connects filtering circuit, and the A/D collection terminal of the output terminal of filtering circuit and single-chip microcomputer is connected; Single-chip microcomputer is connected with Distributed Feedback Laser provides the drive current of trapezoidal wave signal electric current as Distributed Feedback Laser work for it; Another input end that single-chip microcomputer is connected to differential amplifier circuit provides input signal for the differential amplifier circuit input end;
Described calibration system comprises Distributed Feedback Laser, fiber coupler, air chamber, optical fiber collimator, a PIN photodetector, the 2nd PIN photodetector, differential amplifier circuit, filtering circuit and single-chip microcomputer, before Distributed Feedback Laser is positioned at fiber coupler, fiber coupler output terminal branch is made two-way, one the tunnel is connected to optical fiber collimator through optical fiber, optical fiber collimator is positioned at air chamber, and the other end of optical fiber collimator is coupled on the PIN photodetector through the optical fiber connection; Another output terminal of fiber coupler is directly coupled on the 2nd PIN photodetector through the optical fiber connection; The output terminal of the 2nd PIN photodetector is connected to an input end of differential amplifier circuit, and the output terminal of the same PIN photodetector of another input end of differential amplifier circuit or single-chip microcomputer are connected and provide the trapezoidal wave input signal for it; The output terminal of differential amplifier circuit connects filtering circuit, and the A/D collection terminal of the output terminal of filtering circuit and single-chip microcomputer is connected; Single-chip microcomputer is connected with Distributed Feedback Laser provides the drive current of trapezoidal wave signal electric current as Distributed Feedback Laser work for it.
Described trapezoidal wave drives signal characteristic, and upper base trapezoidal in the monocycle is identical with the shared time scale of going to the bottom, and the inclined degree of two waists is identical.
Be the trace aqueous vapor pick-up unit of reference with fiber gas sensor device inside water, with this device aqueous vapor concentration detected to be divided into and demarcate and measure the two large divisions and carry out:
This device be utilize fiber gas sensor part of devices inside water as a reference, detect the trace aqueous vapor in the air chamber.Therefore at first to demarcate the liquid water content of these device insides.
The method that a kind of calibration system that utilizes above-mentioned detection device is demarcated the liquid water content of device inside, step is as follows:
Two input ends of the trapezoidal wave signal access differential amplifying circuit that the photoelectric conversion signal of the 2nd PIN photodetector and single-chip microcomputer are produced; Regulate the enlargement factor of the photoelectric conversion signal of the 2nd PIN photodetector, receive the output terminal of the 2nd PIN photodetector with oscillograph and observe its waveform, reach consistent up to amplitude and the slope of a curve of the photoelectric conversion signal of the 2nd PIN photodetector with the trapezoidal wave signal that single-chip microcomputer produces; Obtain magnitude of voltage V by single-chip microcomputer output
1, this magnitude of voltage is the voltage difference of absorption peak peak value and trapezoidal wave bottom respective value; V
1Aqueous vapor in corresponding Distributed Feedback Laser and the 2nd PIN photodetector;
After the content of the inner water that exists to the fiber gas sensor part of devices had been done to demarcate, utilizing with fiber gas sensor device inside water was that the trace aqueous vapor pick-up unit of reference is measured the aqueous vapor concentration in the air chamber.
A kind of above-mentioned detection device of utilizing is carried out the method that the trace aqueous vapor detects to gas to be measured, and step is as follows:
1. connect detection system; Open the oscillograph power supply; Open the power supply of calibration system; Debugging light path and circuit make its operate as normal; Gas to be measured is passed in the air chamber;
2. step in the trapezoidal wave signal that produces of control single chip computer and calibration system the method that the liquid water content of device inside is demarcated
The trapezoidal wave signal size that middle single-chip microcomputer produces is identical; Two input ends of the trapezoidal wave signal access differential amplifying circuit that the photoelectric conversion signal of PIN photodetector and single-chip microcomputer are produced; Regulate the enlargement factor of the photoelectric conversion signal of PIN photodetector, observe its waveform with oscillograph, reach consistent up to amplitude and the slope of a curve of the photoelectric conversion signal of PIN photodetector with the trapezoidal wave signal of single-chip microcomputer generation; Collect the voltage difference V of the corresponding value in absorption peak peak value and trapezoidal wave bottom, the gentle indoor aqueous vapor of aqueous vapor, PIN photodetector in V correspondence Distributed Feedback Laser, the optical fiber collimator by single-chip microcomputer;
3. in the corresponding Distributed Feedback Laser of the V that measures in the above-mentioned steps, the optical fiber collimator and air chamber aqueous vapor, three device inside water of PIN photodetector and air chamber in aqueous vapor to be measured, the influence of device inside water generates is measured in the method that calibration system is demarcated the liquid water content of device inside, as reference calculation V
0+ V
1Shared ratio in V gets the absorptivity that aqueous vapor to be measured produces laser in the discharge chamber, recycling absorptivity formula η=1-exp[-α (λ) CL)] calculate aqueous vapor concentration;
4. the aqueous vapor concentration of gas to be measured detects and finishes, powered-down, arrangement apparatus.
The used light source of the utility model is that centre wavelength is the Distributed Feedback Laser of 1370nm, and its live width can be considered line spectrum light in the MHz magnitude than sweep limit; The used fiber coupler of calibration system is the 3dB fiber coupler of fused tapered 1 * 2, and its laser of process can be equally divided into two bundles of light intensity ratio 1:1.
The utility model is that the trace aqueous vapor pick-up unit of reference has following advantage with fiber gas sensor device inside water:
Background water in the fiber gas sensor device of Li Yonging as a reference dexterously; The driving that the trapezoidal wave electric current is used for laser instrument makes the waveform adjustment of electric signal become convenient; Saved fiber coupler and only adopted single detector to save cost in the device design; Sensor is not charged, can adopt optical fiber transmission signal, realizes the no electro-detection of aqueous vapor concentration under the particular surroundings.
Description of drawings
Fig. 1 is the synoptic diagram of the utility model trace aqueous vapor pick-up unit.
Wherein: 1, single-chip microcomputer, 2, Distributed Feedback Laser, 3, air chamber, 4, optical fiber collimator, 5, the PIN photodetector, 6, differential amplifier circuit, 7, filtering circuit.
Fig. 2 is the calibration system synoptic diagram, and trace aqueous vapor pick-up unit device Distributed Feedback Laser, optical fiber collimator and three device inside aqueous vapors of PIN photodetector of being used for demarcating based on fiber gas sensor device background water cause absorptivity to laser.
Wherein: 8, single-chip microcomputer, 9, Distributed Feedback Laser, 10, fiber coupler, 11, air chamber, 12, optical fiber collimator, the 13, the one PIN photodetector, the 14, the 2nd PIN photodetector, 15, differential amplifier circuit, 16, filtering circuit.
Embodiment
The utility model is described in further detail below in conjunction with drawings and Examples, but be not limited thereto.
Embodiment:
The embodiment of the utility model device is shown in Fig. 1-2, comprise calibration system, Distributed Feedback Laser 2, air chamber 3, optical fiber collimator 4, PIN photodetector 5, differential amplifier circuit 6, filtering circuit 7 and single-chip microcomputer 1, before it is characterized in that Distributed Feedback Laser 2 is positioned at air chamber 3, optical fiber collimator 4 is positioned at air chamber 3, PIN photodetector 5 is positioned at after the optical fiber collimator 4, optical fiber collimator 4 is coupled on the PIN photodetector 5 through the single-mode fiber connection, PIN photodetector 5 output terminals connect an input end of differential amplifier circuit 6, the output terminal of differential amplifier circuit 6 connects filtering circuit 7, and the A/D collection terminal of the output terminal of filtering circuit 7 and single-chip microcomputer 1 is connected; Single-chip microcomputer 1 is connected with Distributed Feedback Laser 2 provides the drive current of trapezoidal wave signal electric current as Distributed Feedback Laser 2 work for it; Another input end that single-chip microcomputer 1 is connected to differential amplifier circuit 6 provides input signal for differential amplifier circuit 6 input ends;
Described calibration system comprises Distributed Feedback Laser 9, fiber coupler 10, air chamber 11, optical fiber collimator 12, a PIN photodetector 13, the 2nd PIN photodetector 14, differential amplifier circuit 15, filtering circuit 16 and single-chip microcomputer 8, before Distributed Feedback Laser 9 is positioned at fiber coupler 10, fiber coupler 10 output terminal branches are made two-way, one the tunnel is connected to optical fiber collimator 12 through optical fiber, optical fiber collimator 12 is positioned at air chamber 11, and the other end of optical fiber collimator 12 is coupled on the PIN photodetector 13 through the optical fiber connection; Fiber coupler 10 another output terminals were coupled on the 2nd PIN photodetector 14 through direct connection of optical fiber; The output terminal of the 2nd PIN photodetector 14 is connected to an input end of differential amplifier circuit 15, and the output terminal of the same PIN photodetector 13 of another input end of differential amplifier circuit 15 or single-chip microcomputer 8 are connected and provide the trapezoidal wave input signal for it; The output terminal of differential amplifier circuit 15 connects filtering circuit 16, and the A/D collection terminal of the output terminal of filtering circuit 16 and single-chip microcomputer 8 is connected; Single-chip microcomputer 8 is connected with Distributed Feedback Laser 9 provides the drive current of trapezoidal wave signal electric current as Distributed Feedback Laser 9 work for it.
Claims (1)
1. be the trace aqueous vapor pick-up unit of reference with fiber gas sensor device inside water, comprise calibration system, Distributed Feedback Laser, air chamber, optical fiber collimator, the PIN photodetector, differential amplifier circuit, filtering circuit and single-chip microcomputer, before it is characterized in that Distributed Feedback Laser is positioned at air chamber, optical fiber collimator is positioned at air chamber, the PIN photodetector is positioned at after the optical fiber collimator, optical fiber collimator is coupled on the PIN photodetector through the single-mode fiber connection, PIN photodetector output terminal connects an input end of differential amplifier circuit, the output terminal of differential amplifier circuit connects filtering circuit, and the A/D collection terminal of the output terminal of filtering circuit and single-chip microcomputer is connected; Single-chip microcomputer is connected with Distributed Feedback Laser provides the drive current of trapezoidal wave signal electric current as Distributed Feedback Laser work for it; Another input end that single-chip microcomputer is connected to differential amplifier circuit provides input signal for the differential amplifier circuit input end;
Described calibration system comprises Distributed Feedback Laser, fiber coupler, air chamber, optical fiber collimator, a PIN photodetector, the 2nd PIN photodetector, differential amplifier circuit, filtering circuit and single-chip microcomputer, before Distributed Feedback Laser is positioned at fiber coupler, fiber coupler output terminal branch is made two-way, one the tunnel is connected to optical fiber collimator through optical fiber, optical fiber collimator is positioned at air chamber, and the other end of optical fiber collimator is coupled on the PIN photodetector through the optical fiber connection; Another output terminal of fiber coupler is directly coupled on the 2nd PIN photodetector through the optical fiber connection; The output terminal of the 2nd PIN photodetector is connected to an input end of differential amplifier circuit, and the output terminal of the same PIN photodetector of another input end of differential amplifier circuit or single-chip microcomputer are connected and provide the trapezoidal wave input signal for it; The output terminal of differential amplifier circuit connects filtering circuit, and the A/D collection terminal of the output terminal of filtering circuit and single-chip microcomputer is connected; Single-chip microcomputer is connected with Distributed Feedback Laser provides the drive current of trapezoidal wave signal electric current as Distributed Feedback Laser work for it.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201320093238 CN203148838U (en) | 2013-02-28 | 2013-02-28 | Trace moisture detection device taking internal water of optical fiber gas sensor device as reference |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201320093238 CN203148838U (en) | 2013-02-28 | 2013-02-28 | Trace moisture detection device taking internal water of optical fiber gas sensor device as reference |
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| CN203148838U true CN203148838U (en) | 2013-08-21 |
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| CN 201320093238 Expired - Fee Related CN203148838U (en) | 2013-02-28 | 2013-02-28 | Trace moisture detection device taking internal water of optical fiber gas sensor device as reference |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104034685A (en) * | 2014-06-24 | 2014-09-10 | 山东大学 | Enhanced absorption type gas detection system |
| CN106841107A (en) * | 2016-12-30 | 2017-06-13 | 武汉六九传感科技有限公司 | A kind of micro- water detects special butterfly detector |
-
2013
- 2013-02-28 CN CN 201320093238 patent/CN203148838U/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104034685A (en) * | 2014-06-24 | 2014-09-10 | 山东大学 | Enhanced absorption type gas detection system |
| CN104034685B (en) * | 2014-06-24 | 2017-02-15 | 山东大学 | Enhanced absorption type gas detection system |
| CN106841107A (en) * | 2016-12-30 | 2017-06-13 | 武汉六九传感科技有限公司 | A kind of micro- water detects special butterfly detector |
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|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20130821 Termination date: 20160228 |