CN203365315U - Gas concentration detection device - Google Patents
Gas concentration detection device Download PDFInfo
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- CN203365315U CN203365315U CN2013202989599U CN201320298959U CN203365315U CN 203365315 U CN203365315 U CN 203365315U CN 2013202989599 U CN2013202989599 U CN 2013202989599U CN 201320298959 U CN201320298959 U CN 201320298959U CN 203365315 U CN203365315 U CN 203365315U
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Abstract
The utility model relates to the technical field of detection equipment, in particular to a gas concentration detection device. The gas concentration detection device comprises a Fabry-Perot cavity, a wide-frequency-spectrum light source, a photoelectric conversion device and a signal processing device, wherein the length of the Fabry-Perot cavity meets the wave length of absorbed light of detected gas; light emitted by the wide-frequency-spectrum light source irradiates into the Fabry-Perot cavity, then a plurality of beams of interference light are formed in the Fabry-Perot cavity, and emission light strength is detected by the photoelectric conversion device and the signal processing device and the concentration of the detected gas is calculated. In the gas concentration detection device, both light absorption and filtering of the to-be-detected gas are performed in the Fabry-Perot cavity, so that the structure is simpler, and the gas concentration detection device has the advantages that the sensitivity and the resolution are high, the device is portable, the stability is good, and the concentration of the to-be-detected gas can be detected in real time at the same time.
Description
Technical field
The utility model relates to a kind of checkout equipment technical field, particularly a kind of gas concentration detection apparatus.
Background technology
Along with the raising of living standards of the people, house decoration universal, indoor decoration pollution is constantly corroding the health of human body, and wherein formaldehyde (chemical molecular formula HCHO) is maximum, the harmful gas at most of harm in the various pollutants that bring of finishing material.Formaldehyde is a kind of colourless, and the gas of intense stimulus smell is arranged, and has more highly toxic material, by the World Health Organization (WHO), is confirmed as teratogenesis, carcinogen, is allergen, and Long Term Contact will cause gene mutation.
Family's indoor formaldehyde be mainly derived from multiple building materials, ornament materials, furniture, textile etc., these materials all distribute formaldehyde gas under certain temperature, humidity in room air.Especially at indoor closed state, air does not flow, and causes indoor formaldehyde concentration more and more higher, more easily causes formaldehyde poisoning.Formaldehyde is mainly manifested in the aspects such as allotriosmia, stimulation, allergy, abnormal pulmonary function, dysfunction of liver and immunologic dysfunction to the impact of health.Long Term Contact low dosage formaldehyde can cause degradation under chronic respiratory disease, nasopharyngeal carcinoma, colon cancer, brain tumor, paramenia, pregnancy syndrome, leukaemia and teenager's memory and intelligence, when dosage reaches 30mg/m
3the time, can the causing death.Therefore, the concentration of Real-Time Monitoring Formaldehyde in Environment, have great importance for personal safety and environmental protection.
Tradition is measured the concentration of formaldehyde method has spectrophotometric method, chromatography, polarography, the methods such as infrared spectrum absorption process.Spectrophotometry formaldehyde is to utilize formaldehyde to react with developer to generate stable compound, and its color depth is directly proportional to content of formaldehyde, with spectrophotometer, carries out colorimetric analysis; The method detects formaldehyde, and instrument and equipment is simple, easy and simple to handle, small investment, but spectrophotometric method to absorption liquid have relatively high expectations, sensitivity is low and unstable.Chromatography is a kind of method for separating and analyzing, and the difference of its partition factor between mutually fixing and mobile phase according to amalyzing substances reaches the separation purpose, and converts the concentration of amalyzing substances to easily measured electric signal, then by the registering instrument record; Have efficiently, at a high speed, the advantage such as high sensitivity, amount of samples be few, but operation more complicated.Polarography be utilize formaldehyde in the solution of certain pH value can and the characteristic of Cucumber generation redox reaction it is detected, but the advantage of polarography is Application standard addition method working sample, being conducive to eliminate matrix disturbs, but it is mercury electrode that polarography detects the formaldehyde common electrode, this can cause mercury pollution to environment.The infrared spectrum absorption process is to utilize the absorption peak of gas in the silica fibre transmission window, measures because formaldehyde gas absorbs the light intensity attenuation produced, and is finally inversed by the concentration of gas; The method has high resolution, the advantages such as high sensitivity, but the assay device structures more complicated of the method, and for example gas infrared absorption and gas filtering are independently to install.Above concentration of formaldehyde analytical approach is known, spectrophotometric method, the method such as chromatography, polarography all needs first at monitoring field, to gather gaseous sample, again sample being taken back to laboratory is analyzed, analytical cycle is long, cost is high, and complex steps can not reflect in real time the situation of formaldehyde pollution and meet the monitoring requirements of on-the-spot large quantities of measuring points; And the assay device structures complexity of infrared spectrum absorption process structure brings some inconvenience to detection.
The utility model content
In view of the deficiency that prior art exists, it is high that the utility model aims to provide a kind of precision, simple in structure, is suitable for the formaldehyde gas concentration detection apparatus of practical application.
The purpose of this utility model is achieved in that
Gas concentration detection apparatus, comprise Fabry-Perot-type cavity, wide spectrum light source, photoelectric conversion device and signal processing apparatus; Described Fabry-Perot-type cavity is enclosed construction, and the long absorption optical wavelength with the gas that detects in the chamber of Fabry-Perot-type cavity meets
fabry-Perot-type cavity is provided with gas access, incident light mouth and emergent light mouth, and the inwall of Fabry-Perot-type cavity is coated with reflectance coating; Described wide spectrum light source is positioned at the incident light mouth place of Fabry-Perot-type cavity, as the incident light source of Fabry-Perot-type cavity; Photoelectric conversion device is positioned at the emergent light mouth place of Fabry-Perot-type cavity and is connected with the signal processing apparatus electric signal, the emergent light of photoelectric conversion device Receiving Fabry-Perot-type cavity and be converted into electric signal after the input signal treating apparatus; Signal processing apparatus is for processing to the electric signal received the concentration that calculates detected gas, and by structure output to display device; Also comprise power supply, for power consumer apparatus is powered.
Fabry-Perot-type cavity is the spectral absorption chamber of gas absorption light to be detected, is also other wave filters simultaneously, can filter gas absorption light to be detected light signal in addition.
Further, described photoelectric conversion device is photodiode, and photodiode and wide spectrum light source opposite disposed are at the two ends of Fabry-Perot-type cavity.
Further, described Fabry-Perot-type cavity is cylindrical shape, and this barrel bore meets with the absorption optical wavelength of the gas that detects
Further, the reflectivity of reflectance coating is 96%.
Further, place, described gas access is provided with the steam isolating construction.
The steam isolating construction increased is conducive to the anti-external interference of equipment, keeps the stability of monitoring.
Further, also comprise cylindrical housing, described steam isolating construction is arranged on the upper position of described shell, and described Fabry-Perot-type cavity, wide spectrum light source and photoelectric conversion device are arranged on the medium position of shell, and described signal processing apparatus is arranged on the lower position of shell.
The encapsulating structure integrated level is high, simple and compact for structure, is suitable for the engineering application.
Further, described power supply is accumulator or the civil power after pressure regulation.
Different electric energy is supplied with can adapt to different working environments.
Further, the long absorption optical wavelength with formaldehyde in the chamber of described Fabry-Perot-type cavity meets
this equipment can be used for the detection of concentration of formaldehyde
Further, the material of described reflectance coating is zinc.Chemical reaction can not occur in zinc and formaldehyde, can not affect the accuracy that equipment PARA FORMALDEHYDE PRILLS(91,95) concentration detects.
Further, the sandwich construction that described reflectance coating is 16 layers.
Compared with prior art, in the gas concentration detection apparatus that the utility model provides, the light absorption of gas to be measured and filtering are all carried out in Fabry-Perot-type cavity, structure is simpler, has advantages of highly sensitive, high-resolution, portable, good stability simultaneously and can detect in real time gas concentration to be measured.
The accompanying drawing explanation
Fig. 1 is the utility model theory diagram;
Fig. 2 is the utility model example structure schematic diagram.
In figure, identify: 1 steam isolating construction; 2 photodiodes; 3 microprocessors; 4 reflectance coatings; 5 Fabry-Perot-type cavities; 6 wide spectrum light sources; 7 shells; 8 data lines; 9 power leads.
Embodiment
Below in conjunction with drawings and the specific embodiments, the utility model is illustrated; it should be noted that; specific embodiment should not be construed as restriction of the present utility model, and any foundation training centre of the present utility model is done to obtain any change or replacement, all belongs to protection domain of the present utility model.
The present embodiment is the application of the utility model for detection of air formaldehyde concentration, this gas-detecting device outward appearance is a diameter 15mm as shown in Figure 2, height is the right cylinder of 30mm, comprise a columnar titanium alloy casing 7, Fabry-Perot-type cavity 5, wide spectrum light source 6 and photodiode 2 are arranged on the medium position of shell 7, Fabry-Perot-type cavity 5 is enclosed construction, gas access is offered on its top, both sides are provided with incident light mouth and emergent light mouth, wide spectrum light source 6 is positioned at the incident light mouth place of Fabry-Perot-type cavity 5, as the incident light source of Fabry-Perot-type cavity 5; Photodiode 2 is positioned at the emergent light mouth place of Fabry-Perot-type cavity 5 and is connected with microprocessor 3 electric signal, and photodiode 2 and wide spectrum light source 6 opposite disposed are at the two ends of Fabry-Perot-type cavity
For the accuracy that guarantees that this equipment PARA FORMALDEHYDE PRILLS(91,95) concentration detects, above-mentioned reflectance coating 4 has adopted the Zinc material reflectance coating 4 of 16 layers of structure, makes reflectivity reach 96%.
After understanding the present embodiment said structure, to detecting principle, be described further:
The light beam of the wide spectrum that described wide spectrum light source 6 sends, incide in Fabry-Perot-type cavity 5.Formaldehyde gas by gas inlet device 1 in entering Fabry-Perot-type cavity 5.According to the light absorption principle, when the source emissioning light wavelength overlaps with gas (formaldehyde) absorption peak wavelength, resonance absorption will occur in molecule, the power of its absorption is relevant with the length of the absorption characteristic of gas, gas concentration and absorption light path, can mean its absorbing rule to light with Lambert-Beer (lambert-Bill) law.
I(λ)＝I
0(λ)e
-∫c(L)a(λ)dL (1)
Wherein I (λ) passes through the transmitted light intensity after gas medium (Medium) absorbs, I for light
0(λ) light intensity while being initial incident gas medium, the absorption coefficient of light that a (λ) is gas medium, c (L) is gas medium concentration, L means optical path length.When gas concentration is even, c=c (L).Can obtain the gas concentration measurement formula is:
According to above principle, gas absorption coefficient of light a to be measured (λ) determines, L is the length that absorbs light path.The concentration of gas is higher, and its degree that absorbs light signal is just higher, and the intensity of the light signal remained is just less.
Fabry-Perot-type cavity 5 inwalls are coated with reflectance coating 4, after the light beam of wide spectrum light source 6 is injected into Fabry-Perot-type cavity 5 the insides, light just repeatedly comes and goes reflection in Fabry-Perot-type cavity 5, and this series of reflected light signal is interfered according to the length of Fabry-Perot-type cavity 5, forms multi beam and interferes.Its length and transmission peak wavelength relation are satisfied with
λ is the outgoing wavelength, the refractive index that n is air, and k is interference level, the internal diameter that d is Fabry-Perot-type cavity 5.According to this relation, can select desired transmission peak wavelength by the setting of length.In the utility model, transmission peak wavelength is designed to the specific wavelength of formaldehyde absorption.
The principle of interfering according to multi-beam, the intensity of its transmission peak wavelength is:
I
0for incident intensity, r is light amplitude reflectance on the plated film interface in chamber, R=r
2for the reflectivity of light intensity, by formula, can obtain I
textreme value only relevant with δ, irrelevant with R, but the thin acutance of the maximum value of transmitted light intensity is relevant with R, R is higher, interferes bright fringes just sharper.
By formula (2) and (4), the pass of the intensity of its transmitted light intensity and extraneous formaldehyde gas intensity is
From (5) formula, the concentration of extraneous formaldehyde gas can be measured by the intensity that appears signal.Therefore, by photodiode 2, the transmitted light intensity I (λ) after absorbing by gas medium is transformed into to electric signal, in this electric signal is input to microprocessor 3, according to Lambert-Beer's law, after data being processed to calculating, can obtain the concentration of gas.
Certainly, the concentration that the utility model is not limited in formaldehyde gas detects, but can be used as the technical solution that any gas concentration detects in real time, and while certainly different gas concentrations being detected, need to be long according to the chamber of the absorption characteristic adjustment Fabry-Perot-type cavity of detected gas.
Claims (10)
1. a gas concentration detection apparatus, is characterized in that, comprises Fabry-Perot-type cavity, wide spectrum light source, photoelectric conversion device and signal processing apparatus; Described Fabry-Perot-type cavity is enclosed construction, and the long absorption optical wavelength with the gas that detects in the chamber of Fabry-Perot-type cavity meets
fabry-Perot-type cavity is provided with gas access, incident light mouth and emergent light mouth, and the inwall of Fabry-Perot-type cavity is coated with reflectance coating; Described wide spectrum light source is positioned at the incident light mouth place of Fabry-Perot-type cavity, as the incident light source of Fabry-Perot-type cavity; Photoelectric conversion device is positioned at the emergent light mouth place of Fabry-Perot-type cavity and is connected with the signal processing apparatus electric signal, the emergent light of photoelectric conversion device Receiving Fabry-Perot-type cavity and be converted into electric signal after the input signal treating apparatus; Signal processing apparatus is used for the electric signal received is processed to the concentration that calculates detected gas, and exports result to display device; Also comprise power supply, for power consumer apparatus is powered.
2. gas concentration detection apparatus as claimed in claim 1, is characterized in that, described photoelectric conversion device is photodiode, and photodiode and wide spectrum light source opposite disposed are at the two ends of Fabry-Perot-type cavity.
3. gas concentration detection apparatus as claimed in claim 1, is characterized in that, described Fabry-Perot-type cavity is cylindrical shape, and this barrel bore is satisfied with the absorption optical wavelength of the gas that detects
4. gas concentration detection apparatus as claimed in claim 1, is characterized in that, the reflectivity of reflectance coating is 96%.
5. gas concentration detection apparatus as claimed in claim 1, is characterized in that, place, described gas access is provided with the steam isolating construction.
6. gas concentration detection apparatus as claimed in claim 5, it is characterized in that, also comprise cylindrical housing, described steam isolating construction is arranged on the upper position of described shell, described Fabry-Perot-type cavity, wide spectrum light source and photoelectric conversion device are arranged on the medium position of shell, and described signal processing apparatus is arranged on the lower position of shell.
7. gas concentration detection apparatus as claimed in claim 1, is characterized in that, described power supply is accumulator or the civil power after pressure regulation.
8. as gas concentration detection apparatus as described in claim 1 to 7 any one, it is characterized in that, the long absorption optical wavelength with formaldehyde in the chamber of described Fabry-Perot-type cavity meets
9. as gas concentration detection apparatus as described in claim 1 to 7 any one, it is characterized in that, the material of described reflectance coating is zinc.
10. gas concentration detection apparatus as claimed in claim 9, is characterized in that the sandwich construction that described reflectance coating is 16 layers.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2013202989599U CN203365315U (en) | 2013-05-29 | 2013-05-29 | Gas concentration detection device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2013202989599U CN203365315U (en) | 2013-05-29 | 2013-05-29 | Gas concentration detection device |
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|---|---|
| CN203365315U true CN203365315U (en) | 2013-12-25 |
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| CN2013202989599U Expired - Fee Related CN203365315U (en) | 2013-05-29 | 2013-05-29 | Gas concentration detection device |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105241817A (en) * | 2015-11-01 | 2016-01-13 | 李俊娇 | Optical fiber sensing gas detection device |
| CN104280362B (en) * | 2014-09-22 | 2017-04-05 | 合肥工业大学 | A kind of superheated vapor laser spectrum on-line detecting system |
| WO2020143091A1 (en) * | 2019-01-07 | 2020-07-16 | 大连理工大学 | Multi-cavity superimposed non-resonant photoacoustic cell and gas detection system |
-
2013
- 2013-05-29 CN CN2013202989599U patent/CN203365315U/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104280362B (en) * | 2014-09-22 | 2017-04-05 | 合肥工业大学 | A kind of superheated vapor laser spectrum on-line detecting system |
| CN105241817A (en) * | 2015-11-01 | 2016-01-13 | 李俊娇 | Optical fiber sensing gas detection device |
| WO2020143091A1 (en) * | 2019-01-07 | 2020-07-16 | 大连理工大学 | Multi-cavity superimposed non-resonant photoacoustic cell and gas detection system |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20131225 Termination date: 20140529 |