CN102288645A - Rice field methane concentration sensor - Google Patents
Rice field methane concentration sensor Download PDFInfo
- Publication number
- CN102288645A CN102288645A CN 201110200030 CN201110200030A CN102288645A CN 102288645 A CN102288645 A CN 102288645A CN 201110200030 CN201110200030 CN 201110200030 CN 201110200030 A CN201110200030 A CN 201110200030A CN 102288645 A CN102288645 A CN 102288645A
- Authority
- CN
- China
- Prior art keywords
- probe
- methane
- methane concentration
- paddy
- concentration sensor
- 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.)
- Granted
Links
Images
Landscapes
- Investigating Or Analysing Materials By Optical Means (AREA)
Abstract
The invention discloses a rice field methane concentration sensor, which comprises a methane probe, a temperature probe, an actuating signal source, a conditioning circuit and a sensor interface, wherein the actuating signal source is connected with the methane probe and the temperature probe respectively; the conditioning circuit is connected with the methane probe, the temperature probe and the sensor interface respectively; the methane probe and the temperature probe are driven by the actuating signal source; after a driving response signal is filtered and amplified by the conditioning circuit, an output voltage Vm of the methane probe, an output voltage Vt of the temperature probe, and a voltage Vd and a null voltage V0 of the actuating signal source are generated; and the voltages Vm, Vt, Vd and V0 are output to the sensor interface. The rice field methane concentration sensor has a simple structure and low cost, and is easy and convenient to operate.
Description
Technical field
The present invention relates to the field information acquisition field, particularly a kind of paddy methane concentration sensor based on the hot wire type gas sensor.
Background technology
Human activities such as burning along with process of industrialization acceleration, population growth, the utilization of irrational soil, large-area deforestation, a large amount of mineral fuel are constantly risen greenhouse gases such as discharge capacitys such as carbon dioxide, methane.The greenhouse effect that greenhouse gases cause, the serious consequence of many threat human survivals such as will to cause that extreme climate generation, The grain yield drops, the ecosystem change, water resource more is becoming tight scarce, forest fire and development.
Methane is the important greenhouse gases that are only second to carbon dioxide, studies show that, methane has the greenhouse effect stronger than carbon dioxide, and the radiation intensity of unit mole of methane is 21 times of carbon dioxide.Although 0.5% of the not enough carbon dioxide of methane concentration can reach 1/3 of carbon dioxide to the contribution of greenhouse effect, can reach more than 15% the contribution of global warming.
The rice field is one of most important emission source of methane, is the important factor in order that the air sphere methane concentration continues rising.It is to adopt the method for static chamber-gas chromatograph that paddy methane concentration detects the most frequently used method.This method uses the chest at a no end to cover institute's geodetic table, extracts air sample in the case with needle tubing at set intervals, measures its methane concentration by gas chromatograph at last.The weak point of this method is, equipment price costliness, measuring process are subjected to environmental perturbation and manual operation etc. to influence, observe personnel's workload big etc. easily.
The Chinese invention patent application that disclosed publication number was CN1063362A on August 5th, 1992 discloses a kind of paddy methane and has gathered automatically and analytic system, comprise circuit kit and air-path control system in this scheme, be mainly used in the automatic collection of gas in the static chamber, its analytic system still is a gas chromatograph, but is difficult to satisfy requirements such as quick, the convenient and low cost of modern rice field information acquisition.
Based on the research that under paddy environment, is not applied as yet at present of the sensing methane concentration device of gas sensor, reason is that paddy methane concentration is very low, and gas sensor response is little, and influenced by extraneous factor such as temperature, signal to noise ratio (S/N ratio) is lower, and measuring accuracy and stability all are difficult to guarantee.
Summary of the invention
At the deficiency of above-mentioned existing paddy methane concentration detection technique, the purpose of this invention is to provide a kind of simple in structure, easy and simple to handle and lower-cost paddy methane concentration sensor.
The present invention adopts following technical scheme to realize above-mentioned purpose: this paddy methane concentration sensor, comprise methane probe, temp probe, exciting signal source, modulate circuit and sensor interface, exciting signal source is connected with temp probe with the methane probe respectively, and modulate circuit is connected with methane probe, temp probe and sensor interface respectively; Methane probe and temp probe are driven by exciting signal source, and the response signal of driving produces the output voltage V of methane probe after modulate circuit filtering, processing and amplifying
m, temp probe output voltage V
t, exciting signal source voltage V
dAnd total null voltage V
0Described voltage V
m, V
t, V
dAnd V
0Together export sensor interface to.
Described methane probe is the hot wire type gas sensor, and the hot wire type gas sensor is made of sensitive resistance and compensating resistance, and wherein compensating resistance and sensitive resistance have the same datum resistance.The sensitive material of described sensitive resistance is a tin ash.
Above-mentioned paddy methane concentration sensor also comprises interconnective data acquisition module and host computer; Sensor interface by cable with described voltage V
m, V
t, V
dAnd V
0Be sent to data acquisition module and carry out A/D conversion, transformation result is sent to host computer and preserves and show.
Described data acquisition module is provided with and is no less than 4 data acquisition channels that are connected with sensor interface, and is provided with COM or the USB port that is connected with host computer.
Described modulate circuit comprises low-frequency filter circuit and the amplifying circuit that is connected.Described low-frequency filter circuit is the RC circuit.
Compared with prior art, the present invention has following advantage:
1, sensor is installed in the static chamber inner tip, and static chamber is provided with thermometer socket and air sampling mouth, by the methane concentration in the gas chromatograph acquisition static chamber, can demarcate sensor measurement.
2, sensor construction of the present invention is simple, easy and simple to handle, with low cost and reliable and stable.
Description of drawings
Fig. 1 is a paddy methane concentration sensor structural drawing of the present invention;
Wherein: 1, sensor outer housing; 2, accurate exciting signal source; 3, hot wire type methane probe; 4, temp probe; 5, modulate circuit; 6, sensor interface; 7, cable; 8, data acquisition module; 9, host computer.
Fig. 2 is a paddy methane concentration sensor instrumentation plan of the present invention;
Wherein: 10, static chamber; 11, electric fan; 12, thermometer socket and thermometer; 13, air sampling mouth and sampler.
Embodiment
Below in conjunction with drawings and Examples, the present invention is described further, but embodiments of the present invention are not limited thereto.
The present invention is from following problem: problem 1, agricultural product home environment information cognition technology and equipment, national 863 major projects, 2011AA100704,2011-2013; Problem 2, the obtaining fast and analysis research of paddy rice-paddy environment system important information, NSFC-Guangdong associating fund, U0931001,2010-2013.
Paddy methane concentration sensor of the present invention as shown in Figure 1, comprise sensor outer housing 1, place methane probe 3, temp probe 4, accurate exciting signal source 2, modulate circuit 5 and the sensor interface 6 of shell 1 inside, exciting signal source 2 is connected with temp probe 4 with methane probe 3 respectively, and modulate circuit 5 pops one's head in 3 with methane respectively, temp probe 4 is connected with sensor interface 6.Methane probe 3 and temp probe 4 are driven by accurate exciting signal source 2, and the response signal of driving produces 4 road output voltages after modulate circuit 5 filtering, processing and amplifying, are respectively the output voltage V of methane probe 3
m, temp probe 4 output voltage V
t, accurate exciting signal source 2 voltage V
dAnd total null voltage V
0, 4 road output voltages carry out A/D conversion by be connected to data acquisition module 8 by cable 7 behind sensor interface 6, are sent to host computer 9 by COM or USB port then and preserve and show.Wherein the methane probe is exported V
mBy V
t, V
dAnd V
0Carry out zero correction and temperature correction: zero correction is used to eliminate the influence of cable transmission loss; Temperature correction is used to eliminate the influence of environment temperature to methane probe 3, is realized by special-purpose chip temperature or electronic component with temperature effect.
The probe segment of methane probe 3 and temp probe 4 places shell 1 outside, and the line of methane probe 3 and temp probe 4 partly places shell 1 inside, is connected to accurate exciting signal source 2 and modulate circuit 5.
In the present embodiment, methane probe 3 is the hot wire type gas sensor, the hot wire type gas sensor is made of sensitive resistance and compensating resistance, and wherein compensating resistance and sensitive resistance have the same datum resistance, and sensitive resistance and compensating resistance are respectively as two brachium pontis of Huygens's electric bridge; The sensitive material of sensitive resistance is a tin ash, and its resistance value changes along with the variation of methane concentration around it, thereby the output voltage of Huygens's electric bridge is changed.
In the present embodiment, modulate circuit 5 mainly comprises low-frequency filter circuit and the amplifying circuit that is connected, and low-frequency filter circuit adopts the RC circuit to realize, amplifying circuit can adopt instrument amplifier to realize.Accurate exciting signal source 2 produces positive and negative DC voltage for external power source through the power source special chip, is connected to pop one's head in 3 input end of methane.
Measuring process as shown in Figure 2, the paddy methane concentration sensor is installed in static chamber 10 inner tip, static chamber 10 lower ending openings and covering in measuring process on the face of land, measured rice field; Static chamber 10 bosoms are equipped with electric fan, and being used for stirring wherein, air makes it even; Air sample tap and thermometer socket are arranged at static chamber 10 tops.A period of time after the paddy methane concentration sensor energized (generally being made as 10 minutes) is the sensor warm-up phase.In the measuring process, (5 or 10 minutes) are read the numerical value of thermometer 12 and are extracted certain volume air in the static chamber 10 by sampler 13 at regular intervals, detect wherein methane concentration so that sensor measurement is demarcated by gas chromatograph.
Paddy methane concentration sensor output calibration process is as follows:
(1) zero correction of methane probe and temp probe output can be by following formula (1) and (2) expression, and wherein Vd0 is the desired voltage value of exciting signal source, is the output nominal value (as 3V) of power source special chip.
V
m1＝(V
m-V
0)*(V
d0/V
d) (1)
V
t1＝(V
t-V
0)*(V
d0/V
d) (2)
(2) temperature correction and the zero migration correction of methane probe, as shown in Equation (3).
V
m1＝V
m1-f(V
t1)-ΔV (3)
Wherein, f (Vt1) is the temperature characterisitic function of methane probe, its preparation method is under laboratory environment, methane concentration is regarded as ATMOSPHERICAL BACKGROUND concentration and remains unchanged, sensor places a temperature adjustable space (as baking oven), record methane probe and temp probe output result just can obtain f (Vt1) function under specified temp.Δ Vd is methane probe output zero migration, Δ V=0 ideally, and in actual applications, Δ V can be changed by the Vm output of each measurement the previous day and obtains.
The result of air sample after gas chromatograph detects who is obtained by sampler 13 is considered as methane concentration true value in the static chamber 10, can set up the predictive equation of paddy methane concentration sensor with this, obtains the methane concentration in the different static chamber 10 constantly; The stability of this predictive equation and reliability can be undertaken by cross validation.
Different paddy methane concentration constantly according to prediction obtains just can further obtain methane concentration function over time, under the physical dimension situation, just can try to achieve the paddy methane emission flux in known quiescent state case 10.
The foregoing description is a preferred implementation of the present invention; but embodiments of the present invention are not restricted to the described embodiments; other any do not deviate from change, the modification done under spirit of the present invention and the principle, substitutes, combination, simplify; all should be the substitute mode of equivalence, be included within protection scope of the present invention.
Claims (7)
1. paddy methane concentration sensor, it is characterized in that, comprise methane probe, temp probe, exciting signal source, modulate circuit and sensor interface, exciting signal source is connected with temp probe with the methane probe respectively, and modulate circuit is connected with methane probe, temp probe and sensor interface respectively; Methane probe and temp probe are driven by exciting signal source, and the response signal of driving produces the output voltage V of methane probe after modulate circuit filtering, processing and amplifying
m, temp probe output voltage V
t, exciting signal source voltage V
dAnd total null voltage V
0Described voltage V
m, V
t, V
dAnd V
0Together export sensor interface to.
2. paddy methane concentration sensor according to claim 1, it is characterized in that: described methane probe is the hot wire type gas sensor, the hot wire type gas sensor is made of sensitive resistance and compensating resistance, and wherein compensating resistance and sensitive resistance have the same datum resistance.
3. paddy methane concentration sensor according to claim 2 is characterized in that: the sensitive material of described sensitive resistance is a tin ash.
4. paddy methane concentration sensor according to claim 1 is characterized in that: also comprise interconnective data acquisition module and host computer; Sensor interface by cable with described voltage V
m, V
t, V
dAnd V
0Be sent to data acquisition module and carry out A/D conversion, transformation result is sent to host computer and preserves and show.
5. paddy methane concentration sensor according to claim 4 is characterized in that: described data acquisition module is provided with and is no less than 4 data acquisition channels that are connected with sensor interface, and is provided with COM or the USB port that is connected with host computer.
6. paddy methane concentration sensor according to claim 1 is characterized in that: described modulate circuit comprises low-frequency filter circuit and the amplifying circuit that is connected.
7. paddy methane concentration sensor according to claim 6 is characterized in that: described low-frequency filter circuit is the RC circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201110200030 CN102288645B (en) | 2011-07-18 | 2011-07-18 | Rice field methane concentration sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201110200030 CN102288645B (en) | 2011-07-18 | 2011-07-18 | Rice field methane concentration sensor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102288645A true CN102288645A (en) | 2011-12-21 |
| CN102288645B CN102288645B (en) | 2012-12-19 |
Family
ID=45335240
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201110200030 Active CN102288645B (en) | 2011-07-18 | 2011-07-18 | Rice field methane concentration sensor |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102288645B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104634830A (en) * | 2015-01-26 | 2015-05-20 | 南京大学 | PMMA-SnO2-based thin-film gas sensor for detecting methane |
| CN105606656A (en) * | 2015-11-06 | 2016-05-25 | 上海戴维蓝普传感技术有限公司 | Anti-silicon poisoning anti-sulfur-poisoning hot wire methane sensor |
| CN112630268A (en) * | 2020-11-26 | 2021-04-09 | 燕山大学 | Bipolar miniature ion concentration sensor and measurement system thereof |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1063362A (en) * | 1992-02-24 | 1992-08-05 | 中国科学院大气物理研究所 | Methane is gathered and analytic system automatically |
| JP2001324463A (en) * | 2000-05-12 | 2001-11-22 | Hioki Ee Corp | Gas concentration detection sensor and gas concentration measuring apparatus |
| JP2002214176A (en) * | 2001-01-19 | 2002-07-31 | Fujitsu General Ltd | Gas detector |
| CN2911815Y (en) * | 2006-05-23 | 2007-06-13 | 张玉林 | Well self-inflam monitoring, analysing and controlling system of coal mine |
| US20090038289A1 (en) * | 2007-08-08 | 2009-02-12 | Yamaha Hatsudoki Kabushiki Kaisha | Gas sensor, air-fuel ratio controller, and transportation apparatus |
| JP2009059002A (en) * | 2007-08-29 | 2009-03-19 | Central Res Inst Of Electric Power Ind | Bubble count system |
| CN101788440A (en) * | 2010-01-15 | 2010-07-28 | 清华大学 | Electronic nose used for food safety monitoring |
| CN201796024U (en) * | 2010-09-06 | 2011-04-13 | 北京市华云分析仪器研究所有限公司 | In-situ monitoring device for water body-atmosphere interface methane gas flux |
-
2011
- 2011-07-18 CN CN 201110200030 patent/CN102288645B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1063362A (en) * | 1992-02-24 | 1992-08-05 | 中国科学院大气物理研究所 | Methane is gathered and analytic system automatically |
| JP2001324463A (en) * | 2000-05-12 | 2001-11-22 | Hioki Ee Corp | Gas concentration detection sensor and gas concentration measuring apparatus |
| JP2002214176A (en) * | 2001-01-19 | 2002-07-31 | Fujitsu General Ltd | Gas detector |
| CN2911815Y (en) * | 2006-05-23 | 2007-06-13 | 张玉林 | Well self-inflam monitoring, analysing and controlling system of coal mine |
| US20090038289A1 (en) * | 2007-08-08 | 2009-02-12 | Yamaha Hatsudoki Kabushiki Kaisha | Gas sensor, air-fuel ratio controller, and transportation apparatus |
| JP2009059002A (en) * | 2007-08-29 | 2009-03-19 | Central Res Inst Of Electric Power Ind | Bubble count system |
| CN101788440A (en) * | 2010-01-15 | 2010-07-28 | 清华大学 | Electronic nose used for food safety monitoring |
| CN201796024U (en) * | 2010-09-06 | 2011-04-13 | 北京市华云分析仪器研究所有限公司 | In-situ monitoring device for water body-atmosphere interface methane gas flux |
Non-Patent Citations (3)
| Title |
|---|
| 《JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS》 19930131 KAGAWA,N, ET AL INSITU AND REAL-TIME MEASUREMENT OF METHANE CONCENTRATION IN RICE PADDY FIELD AT OKAYAMA-UNIVERSITY USING TUNABLE DIODE-LASER ABSORPTION SPECTROMETRY 第244-245页 1-7 第32卷, 第1A期 * |
| 《中国科学》 20101231 周志艳，等 水稻-稻田环境系统重要信息快速获取技术研究进展 第38-53页 1-7 第40卷, * |
| 《中国科学院研究生院学报》 19970531 王跃思，等 农田甲烷和氧化亚氮排放自动采样观测系统 第17-22页 1-7 第14卷, 第1期 * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104634830A (en) * | 2015-01-26 | 2015-05-20 | 南京大学 | PMMA-SnO2-based thin-film gas sensor for detecting methane |
| CN105606656A (en) * | 2015-11-06 | 2016-05-25 | 上海戴维蓝普传感技术有限公司 | Anti-silicon poisoning anti-sulfur-poisoning hot wire methane sensor |
| CN105606656B (en) * | 2015-11-06 | 2020-04-21 | 上海戴维蓝普传感技术有限公司 | Hot wire type methane sensor with silicon resistance and sulfur poisoning resistance |
| CN112630268A (en) * | 2020-11-26 | 2021-04-09 | 燕山大学 | Bipolar miniature ion concentration sensor and measurement system thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102288645B (en) | 2012-12-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN207066720U (en) | A kind of LED illumination product stroboscopic effect test system | |
| CN102288645B (en) | Rice field methane concentration sensor | |
| CN202886398U (en) | Hot-bulb anemograph using thermocouple | |
| CN105806505A (en) | GSM-based high-precision remote temperature monitoring system | |
| CN104977430B (en) | One kind is without wind-tunnel virtual thermal air velocity transducer test device | |
| CN104034378A (en) | Constant-current thermal gas mass flow meter and measuring method implemented by same | |
| CN112229457B (en) | Novel electromagnetic flowmeter and measuring method thereof | |
| CN100561195C (en) | The non-disperse infrared spectrum determination method and the device that are suitable for wide environmental temperature range | |
| CN103558265A (en) | Automatic testing system with gas sensitive element | |
| CN202256134U (en) | Infrared analysis meter | |
| CN112097945A (en) | Temperature detector and measuring device for detecting temperature of terminal base of electric energy meter | |
| CN104198035A (en) | Solar irradiance sensor with temperature compensation function | |
| CN204330655U (en) | A kind of portable formaldehyde and PM2.5 pick-up unit | |
| CN204740222U (en) | Gaseous detector in room | |
| CN207231550U (en) | A kind of online moisture of high accuracy grain and temperature monitor | |
| CN209927171U (en) | Weather forecast and environment and water quality monitoring system | |
| CN203089092U (en) | Multichannel shell temperature measuring device with isolation | |
| Subair et al. | Intelligent pressure measuring system | |
| CN203011610U (en) | Novel digital altimeter based on AVR one-chip microcomputer | |
| Zhang et al. | Design and realization of smart toilet flushing water temperature performance detection system | |
| CN202815005U (en) | Hot-bulb anemometer | |
| CN103822658A (en) | Multifunctional integrated transmitter | |
| CN109813866A (en) | The measuring system and measurement method of unsaturation frozen soil matric potential | |
| CN204228640U (en) | Detecting Pesticide equipment | |
| CN110108844A (en) | A kind of Multifunctional environment air quality detection system |
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 |