CN103207217A - Non-plug-in water content sensor of culture substrate and calibration method of sensor - Google Patents
Non-plug-in water content sensor of culture substrate and calibration method of sensor Download PDFInfo
- Publication number
- CN103207217A CN103207217A CN2013101477174A CN201310147717A CN103207217A CN 103207217 A CN103207217 A CN 103207217A CN 2013101477174 A CN2013101477174 A CN 2013101477174A CN 201310147717 A CN201310147717 A CN 201310147717A CN 103207217 A CN103207217 A CN 103207217A
- Authority
- CN
- China
- Prior art keywords
- pole plate
- cultivation matrix
- water content
- sensor
- frequency
- 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
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 title claims abstract description 70
- 238000000034 method Methods 0.000 title claims abstract description 39
- 239000000758 substrate Substances 0.000 title claims abstract description 28
- 239000000523 sample Substances 0.000 claims abstract description 44
- 230000006698 induction Effects 0.000 claims abstract description 22
- 239000011159 matrix material Substances 0.000 claims description 68
- 238000003780 insertion Methods 0.000 claims description 27
- 230000037431 insertion Effects 0.000 claims description 27
- 238000005259 measurement Methods 0.000 claims description 21
- 238000006243 chemical reaction Methods 0.000 claims description 14
- 230000001939 inductive effect Effects 0.000 claims description 10
- 230000005684 electric field Effects 0.000 claims description 6
- 238000009413 insulation Methods 0.000 claims description 6
- 239000000203 mixture Substances 0.000 claims description 6
- 238000002156 mixing Methods 0.000 claims description 5
- 230000009471 action Effects 0.000 claims description 4
- 239000003795 chemical substances by application Substances 0.000 claims description 4
- 239000011248 coating agent Substances 0.000 claims description 4
- 238000000576 coating method Methods 0.000 claims description 4
- 239000003292 glue Substances 0.000 claims description 3
- 230000008569 process Effects 0.000 abstract description 6
- 230000008901 benefit Effects 0.000 abstract description 4
- 239000002344 surface layer Substances 0.000 abstract 1
- 239000002689 soil Substances 0.000 description 26
- 239000003570 air Substances 0.000 description 10
- 238000010586 diagram Methods 0.000 description 10
- 238000005516 engineering process Methods 0.000 description 7
- 239000003415 peat Substances 0.000 description 5
- 235000021419 vinegar Nutrition 0.000 description 5
- 239000000052 vinegar Substances 0.000 description 5
- 238000012360 testing method Methods 0.000 description 4
- 238000010276 construction Methods 0.000 description 3
- 230000007812 deficiency Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000002245 particle Substances 0.000 description 3
- 230000035945 sensitivity Effects 0.000 description 3
- 239000008187 granular material Substances 0.000 description 2
- 238000003973 irrigation Methods 0.000 description 2
- 230000002262 irrigation Effects 0.000 description 2
- 238000012856 packing Methods 0.000 description 2
- 238000002310 reflectometry Methods 0.000 description 2
- 229920006395 saturated elastomer Polymers 0.000 description 2
- 238000004088 simulation Methods 0.000 description 2
- 230000009466 transformation Effects 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical group [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 241000196324 Embryophyta Species 0.000 description 1
- 238000012271 agricultural production Methods 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 238000003556 assay Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000002146 bilateral effect Effects 0.000 description 1
- 239000003990 capacitor Substances 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000005056 compaction Methods 0.000 description 1
- 239000008367 deionised water Substances 0.000 description 1
- 229910021641 deionized water Inorganic materials 0.000 description 1
- 238000009795 derivation Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 238000003898 horticulture Methods 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 238000001225 nuclear magnetic resonance method Methods 0.000 description 1
- 238000000643 oven drying Methods 0.000 description 1
- 238000013021 overheating Methods 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 238000004611 spectroscopical analysis Methods 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 230000006641 stabilisation Effects 0.000 description 1
- 238000011105 stabilization Methods 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 238000012549 training Methods 0.000 description 1
- 230000001131 transforming effect Effects 0.000 description 1
Images
Landscapes
- Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
Abstract
本发明公开了一种非插入式栽培基质含水量传感器，包括单侧敏感型电容式探头、设置有电容测量电路的电路主板、输入输出接口电缆，单侧敏感型电容式探头包括驱动极板、感应极板、屏蔽极板和基片，驱动极板和感应极板位于基片的同一表面上，屏蔽极板位于基片的另一表面上，感应极板和屏蔽极板具有等电位。本发明还公开了该传感器的标定模型，根据传感器在干基质中和任意一点已知栽培基质含水量输出电压信号，确定标定模型中的参数β，依次确定标定方程。本发明所述传感器具有获取栽培基质表层含水量能力，具有成本低，性能稳定，输入输出接口简单、标定过程方便简单等优点，其标定模型及基于此模型的两点标定模型方法具有快速、简单的特点。
The invention discloses a non-plug-in cultivation substrate water content sensor, which comprises a one-side sensitive capacitive probe, a circuit board provided with a capacitance measuring circuit, and an input and output interface cable. The one-side sensitive capacitive probe includes a driving plate, The induction plate, the shielding plate and the substrate, the driving plate and the sensing plate are located on the same surface of the substrate, the shielding plate is located on the other surface of the substrate, and the sensing plate and the shielding plate have equipotential. The invention also discloses a calibration model of the sensor. According to the output voltage signal of the sensor in the dry substrate and the known cultivation substrate water content at any point, the parameter β in the calibration model is determined, and the calibration equation is sequentially determined. The sensor of the present invention has the ability to obtain the water content of the surface layer of the cultivation substrate, has the advantages of low cost, stable performance, simple input and output interfaces, and a convenient and simple calibration process. Its calibration model and the two-point calibration model method based on this model are fast and simple. specialty.
Description
Technical field
The present invention relates to a kind of non-insertion water content sensor and scaling method thereof, relate in particular to a kind of one-sided responsive type, be used for 2 caliberating devices and the scaling method thereof of non-insertion sensor that the cultivation matrix water cut detects and peg model thereof.
Background technology
Soil moisture measurement is the basis of implementing water-saving irrigation in the precision agriculture, is the key link that realizes the agricultural irrigation robotization.Along with wireless distributed monitoring soil moisture network system use day by day ripe, be badly in need of a kind of measuring accuracy height, low in energy consumption, price is low, structure is little, the simple water content sensor of calibration process.In addition, in facilities horticulture, when particularly bag training, potted plant or column mode were planted, soilless culture substrate was loose, makes traditional probe plug-in type moisture transducer probe be difficult to well contact with matrix, easily forms the space, and influences measuring accuracy; And the probe that inserts might damage crop root, therefore, needs a kind of non-insertion cultivation matrix water content sensor.
At present, the assay method of cultivation matrix water cut has oven drying method, rays method, dielectric method, nuclear magnetic resonance method, near infrared spectroscopic method and remote sensing method etc.Wherein, the dielectric method is to measure the cultivation matrix water cut indirectly by measuring the cultivation matrix specific inductive capacity, have quick, harmless advantage, it can be divided into time domain reflectometry (TDR), frequency domain reflectometry (FDR), standing wave ratio method (SWR) and capacitance method again by measuring principle.Capacitance method is to measure the equivalent capacity of inserting the electrode in the cultivation matrix to measure the cultivation matrix water cut, and possess skills simple relatively, low cost and other advantages are subjected to people very early and extensively note.As, it is to scribble one deck by the surface to constitute through the two metal sheets with insulation and non-absorbency ceramic glaze film of high temperature sintering that China Patent No. CN1504745A discloses a kind of capacitance probe; Patent CN101694475B and CN201034964 disclose similarly and a kind ofly have been provided with the copper ring electrode sleeve of insulation shading ring on the hollow insulation rod and will can be used for the condenser type moisture-sensitive device of soil profile moisture measurement in its pvc pipe of packing into two; The probe of above-mentioned 3 patents exists to make trouble or be not suitable for and inserts cultivation matrix and deficiency such as good contact with it.Patent CN102023182A and 201210521545.3 discloses a kind of soil moisture sensor probe that processes based on printed circuit board (PCB) (PCB) technology, it is the bilateral responsive type, all need to insert cultivation matrix and obtain water cut information, can't obtain cultivation matrix top layer water cut information.In addition, in above-mentioned 5 patents transducer calibration model and method are not proposed all.Because the otherness of soil, soilless culture substrate physicochemical property is big, makes that the scale transformation model of setting up in a kind of cultivation matrix is poor for applicability.During using, reality mostly needs to adopt the multiple spot Return Law to select more excellent model to demarcate again to different soils, soilless culture substrate, the method process length consuming time, and unified peg model is unfavorable for the product promotion use.There are scholars that condenser type Soil Moisture Sensor scaling method is studied, as the ECH of Toshihiro Sakaki
2The O sensor proposes 2 α peg models of dry ground, saturated wet soil, has obtained good effect; Gao Yan, Bogena etc. have proposed first demarcation output voltage and specific inductive capacity relation, and the two step standardizations that concern between specific inductive capacity and the water cut are demarcated in the back.These two kinds of scaling methods have deficiency: the saturated wet soil of Toshihiro Sakak is difficult to quantitatively preparation, operation inconvenience; It is different because of the different in kind of soil, soilless culture substrate equally that second step of Gao Yan, Bogena is demarcated the more excellent model of setting up, and do not have adaptability.
Summary of the invention
At above shortcomings in Soil Moisture Sensor in the prior art and the soil moisture measurement technology, different physicochemical property at the relative soil of cultivation matrix, the invention provides that a kind of making is simple, cost is low, non-insertion cultivation matrix water content sensor with one-sided susceptibility, and provide a kind of peg model of this type of sensor, a kind of simple 2 scaling methods are provided.
Technical scheme of the present invention is:
A kind of non-insertion cultivation matrix water content sensor, comprise one-sided responsive type capacitance probe, the mainboard that is provided with capacitance measurement circuit, IO interface cable, described one-sided responsive type capacitance probe comprises driving pole plate, induction pole plate, shielding pole plate and substrate, described driving pole plate and induction pole plate are positioned on the same surface of substrate, described shielding pole plate is positioned on another surface of substrate, and described induction pole plate and shielding pole plate have equipotential.
Further, the capacitance measurement circuit on the described circuit main board comprises power module, resonance modules, secondary frequency division module and lies prostrate converter frequently; Described power module is used for the power supply of dry cell power supply is converted to stable, the ripple-free voltage source that other electron device needs; Described resonance modules is for generation of the frequency signal of responsive cultivation matrix water cut; Described secondary frequency division module comprises prescalar and rearmounted frequency divider, wherein, prescalar is used for realizing presetting frequency division and level conversion function, and rearmounted frequency divider is high-speed asynchronous counter, is used for frequency division of the frequency to frequently lying prostrate in the treatable frequency of conversion circuit; Described frequency volt converter is used for making signal behind the frequency division of rearmounted frequency divider output with the d. c. voltage signal output of equivalence, and as signal of sensor.
Further, described driving pole plate, induction pole plate, shielding polar board surface all are coated with insulating layer coating.
Further, described induction pole plate and the width of shielding pole plate and the ratio of the spacing between them are got between the 0.8-1.
Further, the frequency size of described frequency signal is determined by the equivalent capacity size that with the cultivation matrix is the probe of medium.
Further, described capacitance measurement circuit comprises printed circuit board (PCB) and probe printed panel, and printed circuit board (PCB) is structure as a whole with the probe printed panel.
Further, the components and parts in the described capacitance measurement circuit all are positioned at the same side of shielding pole plate.
Further, described components and parts are all handled through waterproof and dampproof, insulation and the embedding of heat conductivility good electron waterproof glue.
A kind of peg model for described non-insertion cultivation matrix water content sensor, described peg model is
Wherein,
UBe the sensor output voltage signal,
θBe the cultivation matrix water cut of correspondence, parameter
ε w ,
ε a Be the relative dielectric constant of water, air,
A, BValue can be definite by the output voltage of sensing in air and pure water,
U 2 Be sensor sensor output voltage in dried cultivation matrix,
βBe to mix specific inductive capacity parameter empirical value, its size and blending agent geometry, composition, electric field action directional correlation.
A kind of scaling method of the non-insertion cultivation matrix water content sensor based on described model according in butt matter and any known cultivation matrix water cut output voltage signal a bit of sensor, is determined the parameter in the peg model
β, determine calibration equation successively.
The invention has the beneficial effects as follows:
Use simple PCB process technology and circuit theory, a kind of non-insertion cultivation matrix water content sensor is provided, it has the cultivation matrix of obtaining top layer water cut ability; Provided the unified peg model of this type of sensor, and a kind of quick, simple 2 peg model methods are provided; It is low that this kind sensor has a cost, stable performance, advantage such as IO interface is simple, calibration process is convenient and simple.
Description of drawings
Fig. 1 is non-insertion cultivation matrix water content sensor one-piece construction front schematic view;
Fig. 2 is non-insertion cultivation matrix water content sensor one-piece construction reverse side synoptic diagram;
Fig. 3 is the capacitance measurement circuit theory diagram;
Fig. 4 is the resonance modules circuit theory diagrams;
Fig. 5 is secondary frequency division module schematic diagram;
Fig. 6 lies prostrate the converter circuit schematic diagram frequently;
Fig. 7 is rating test data scatter diagrams.
Among the figure: 1, one-sided responsive type capacitance probe; 2, circuit main board; 3, IO interface cable; 4, drive pole plate; 5, induction pole plate; 6, shielding pole plate; 7, substrate.
Embodiment
Below in conjunction with accompanying drawing the present invention is described in further detail.
The present invention is directed to the existing above-mentioned deficiency of Soil Moisture Sensor, different physicochemical property at the relative soil of cultivation matrix, propose that a kind of making is simple, cost is low, non-insertion cultivation matrix water content sensor with one-sided susceptibility, and provide a kind of peg model of this type of sensor, a kind of simple 2 scaling methods are provided.
To achieve these goals, the present invention discloses a kind of non-insertion cultivation matrix water content sensor and scaling method thereof, comprises for responsive cultivation matrix water cut, by the one-sided responsive type capacitance probe of printed circuit board (PCB) (PCB) fabrication techniques; Based on resonance principle, have the capacitance measurement circuit that lies prostrate conversion module frequently; The peg model of deriving based on specific inductive capacity mixture model experimental formula (
βAnd 2 scaling methods model).
One-sided responsive type capacitance probe is made by printed-board technology, and it is formed by driving pole plate, induction pole plate, shielding pole plate and substrate; Driving pole plate, induction pole plate are positioned at the same surface of substrate; The shielding pole plate is positioned at another surface of substrate; Driving pole plate, induction pole plate, shielding polar board surface all are coated with insulating layer coating, effectively avoid the leakage current between the pole plate; Induction pole plate, shielding pole plate have equipotential; Be susceptibility and the responsive degree of depth of taking into account probe, the ratio of described induction pole plate, shielding plate width and the spacing between them is got between the 0.8-1.
Capacitance measurement circuit is made up of power module, resonant element, secondary frequency division module and (F/V) device of volt conversion frequently four parts; That power module is used for that power supply with dry cell power supply is converted to that other electron device needs is stable, the voltage source of ripple-free; Resonant element is the frequency signal that produces responsive cultivation matrix water cut, and its core devices is integrated voltage controlled oscillator (VCO) chip MC12148; The frequency size of frequency signal is to be determined by the equivalent capacity size that is the probe of medium with the cultivation matrix; The equivalent capacity of probe is as required electric capacity in the external resonant groove path of chip MC12148; The secondary frequency division module comprises prescalar and rearmounted frequency divider; Prescalar has the frequency division of presetting and level conversion function; Rearmounted frequency divider is high-speed asynchronous counter, can be with frequency division of the frequency to frequently lying prostrate in the treatable frequency of conversion circuit; Frequently lie prostrate converter and be signal behind the frequency division that makes rearmounted frequency divider output with the d. c. voltage signal output of equivalence, and as signal of sensor;
The printed circuit board (PCB) of capacitance measurement circuit is structure as a whole with the probe printed panel, and the components and parts of capacitance measurement circuit all are positioned at shielding pole plate one side.
The components and parts of circuit are all handled through waterproof and dampproof, insulation and the embedding of heat conductivility good electron waterproof glue, to guarantee sensor long-term stability, reliability service.
The present invention also provides a kind of peg model for this type of non-insertion cultivation matrix water content sensor, and described peg model is:
（1）
Wherein,
UBe the sensor output voltage signal,
θBe the cultivation matrix water cut of correspondence, parameter
ε w ,
ε a Be the relative dielectric constant of water, air,
A, BValue can be definite by the output voltage of sensing in air and pure water,
U 2 Be sensor sensor output voltage in dried cultivation matrix,
βBe to mix specific inductive capacity parameter empirical value, its size and blending agent geometry, composition, electric field action directional correlation;
The method of above-mentioned 2 peg models refer to according to sensor in butt matter and arbitrarily a bit known cultivation matrix water cut output voltage signal determine parameter in the peg model
β, therefore determine calibration equation.
The measuring principle of present embodiment: capacitance method is that a kind of cultivation matrix of forming with matrix granule, water and air by measurement is the capacitance detecting technology of condenser dielectric; Because the specific inductive capacity of water is much larger than matrix granule and dielectric constant of air, soil water content changes, and soil dielectric constant changes, thereby causes that condenser capacitance changes.
As depicted in figs. 1 and 2, be non-insertion cultivation matrix water content sensor one-piece construction pros and cons synoptic diagram of the present invention.From structural representation, the present invention includes one-sided responsive type capacitance probe 1, the circuit main board 2 of measuring sonde capacitance size, IO interface cable 3 for responsive cultivation matrix moisture.
One-sided responsive type capacitance probe 1 is structure as a whole with the circuit main board 2 of measuring sonde capacitance size, makes the sensor compact overall structure.
As shown in Figure 3, be the theory diagram of capacitance measurement circuit in of the present invention; It comprises power module, resonance modules, secondary frequency division module and (F/V) device of volt conversion frequently four parts.
That power module is used for that power supply with dry cell power supply is converted to that other electron device needs is stable, the 5V voltage source of ripple-free; Can adopt AMS1117-5.0 voltage stabilizing chip in the circuit, its inner integrated overheating protection and current-limiting circuit are the preferable selections of powered battery sensor.
Resonance modules is the frequency signal that produces responsive cultivation matrix water cut, and its core devices is integrated voltage controlled oscillator (VCO) chip MC12148, is the resonant element circuit theory diagrams as shown in Figure 4.The frequency size of described frequency signal is by being the equivalent capacity of the probe of medium with the cultivation matrix
CxSize determines, the equivalent capacity of described probe
CxAs required electric capacity in the external resonant groove path of chip MC12148, the MC12148 output signal is the MECL level, and typical highest frequency can reach 225MHz, purity of frequency spectrum height, under 5.0V direct supply voltage, maximum current consumption 19mA, its output signal frequency size calculating formula is:
Wherein,
CBe the inner natural capacity of chip MC12148,
L Be 1 size of inductance L among Fig. 3.
The secondary frequency division module comprises prescalar and rearmounted frequency divider, and Fig. 5 is secondary frequency division module circuit theory diagrams.Described prescalar adopts chip MC12017, and it has 64/63 and presets division function and level conversion function prescalar, maximum operation frequency 225MHz, output level can with COMS, Transistor-Transistor Logic level compatibility; Described rearmounted frequency divider adopts 12 high speed COMS asynchronous counter chip 74HC4040, and its maximum can realize 2
12Frequency division is enough to and will presets frequency division of the frequency behind the frequency division to frequently lying prostrate in the treatable frequency of conversion circuit.
Frequently lying prostrate converter is to make the frequency signal of rearmounted frequency divider output with the d. c. voltage signal output of equivalence, and its core devices is chip LM331, and it is very high V/F and the F/V conversion chip of cost performance that U.S. NS company produces.It has adopted new temperature compensation energy gap reference circuit, under the 4.0V supply voltage high conversion accuracy is arranged with low in whole operating temperature range.When as F/V and in by Fig. 6, connect shown in the circuit, the average current that the 1st pin of LM331 chip flows out is by 9 filtering of the capacitor C of 100k Ω resistance R 2 and 1uf, its ripple peak value is 10mV, but corresponding slower, time constant is 0.1s, reach 0.1% degree of accuracy the stabilization time through 0.7s, and the pass of output voltage signal and frequency input signal is:
U=k·f s （3）
Wherein,
UBe sensor output voltage,
kBe to lie prostrate transformation ratio frequently.
The present invention also provides a kind of peg model for this type of non-insertion cultivation matrix water content sensor, the concrete derivation of model is as follows: receive section's two-phase specific inductive capacity mixture model experimental formula according to Ji Hetian, cultivation matrix is found out that the relative dielectric constant of cultivation matrix can be expressed as by air, cultivation matrix particle and the mixing of water three-phase:
Wherein,
ε b Be the soil relative dielectric constant,
ε a ,
ε s ,
ε w Be respectively the relative dielectric constant of air, soil particle, water,
f a ,
f s ,
θBe respectively the volume fraction of air, soil particle, water,
βBe to mix specific inductive capacity parameter empirical value, its size and blending agent geometry, composition, electric field action directional correlation; In addition,
f a ,
f s ,
θBetween close and to be:
（5）
（6）
Wherein,
φBe the interstices of soil rate, can get according to formula (4)-(6):
When soil volume change of moisture content, the probe equivalent capacity changes thereupon, and the probe equivalent capacity can be expressed as:
C x =
C 0+
ξ·ε b ·ε 0 （8）
Wherein,
C x Be the probe equivalent capacity,
C 0 Be to drive pole plate and shield the equivalent capacity that pole plate forms,
ξBe the sensitivity of probe,
ε 0 It is dielectric constant of vacuum.
Frequently lie prostrate transforming relationship formula (3) according to resonant element resonance signal frequency meter formula (2), F/V conversion circuit chip, and formula (8) can get:
（9）
Order
,
, suppose that sensor probe separately output voltage when air contacts with the deionized water top layer is respectively
U 0 ,
U 1, then have:
（12）
Can be determined by formula (11), (12)
A,
BIn addition, suppose sensor in baking substrate (
θBe 0), output voltage is
U 2 Then can be got by formula (7), (10):
Can get according to formula (7), (10), (13):
Formula (14) be based on
βThe experience peg model of parameter (
βModel).Using
βDuring model calibration, parameter
ε w ,
ε a , be constant, to some sensors
A,
BBe worth identical, so only need determine parameter to different cultivation matrixes
U 2 With
β.Wherein,
U 2 Be sensor output voltage in dried cultivation matrix, according to peg model formula (14), can propose the method for 2 peg models.
The method of described 2 peg models refer to according to sensor in butt matter and arbitrarily a bit known cultivation matrix water cut output voltage signal determine parameter in the peg model
β, therefore determine calibration equation.
For have a mind to effect, the both practicality of sensor, reliability of the present invention are described; And provide
βThe practicality of the adaptability of model and 2 standardizations; With soil, reaching soilless culture substrate peat commonly used and vinegar poor is subjects, carries out rating test.Scaling method is as follows: behind the poor rejecting of air-dry soil, peat and vinegar impurity, be put in dry 3h in 105 ℃ of drying boxes, cool to room temperature is standby; Get the Plastic Drum of internal diameter 13cm, dark 25cm, weigh up empty bucket quality with Precision Electronics Balance, determine to load soil, matrix volume, and mark is done at the corresponding height place in bucket; Calculate required water and the poor quality of dry ground earth, peat and vinegar according to pre-determined volume of sample water cut and unit weight, get by result calculated that dry ground earth, peat, vinegar are poor to be mixed with water, stir, be sealed in leave standstill 24h in the polybag after, will be densified to the place that makes marks in its Plastic Drum of packing into and with it with the compaction in layers method; During measurement, room temperature control closely is contacted with made sample top in (25 ± 3) ℃ with the responsive side of non-insertion cultivation matrix water content sensor, and every rotation is measured 1 time for 120 °, and getting 3 output voltage average values is measured value.Sample is numbered from small to large by water cut, and water cut is 0, is numbered 1.In addition, experimental test obtains:
U 0=1.354V,
U 1=0.405V.Fig. 7 is nominal data, and data are carried out least square fitting
βParameter model, the related coefficient of match
R 2And root-mean-square error (RMSE) is as following table:
Table is as can be known thus:
βPeg model can be described the relation between output voltage signal and the water content of substrate, least correlativing coefficient preferably
R 2=0.9911.
2 scaling methods that propose according to the present invention, we will number big any some test figures and bring formula (16) into, solve parameter
β, determine peg model; Calculate the error of self outer all the other each point calibration value and true value according to peg model, remember that the maximum value of error is M
| △ |Calculate
βAnd M
| △ |Data such as following table:
Table as can be known thus: determine with 2 scaling methods
βPeg model, it is better to be used for the poor measurement effect of soil, peat and vinegar, and their maximum error satisfies the accuracy requirement of agricultural production cultivation matrix moisture measurement less than 0.025.
It should be noted last that: above embodiment is unrestricted real invention technical scheme in order to explanation only, although with reference to above-described embodiment the present invention is had been described in detail, those of ordinary skill in the art is to be understood that: still can make amendment or be equal to replacement the present invention, and not breaking away from any modification or partial replacement of the spirit and scope of the present invention, it all should be encompassed in the middle of the claim scope of the present invention.
Claims (10)
1. non-insertion cultivation matrix water content sensor, it is characterized in that: comprise one-sided responsive type capacitance probe (1), be provided with the circuit main board (2) of capacitance measurement circuit, IO interface cable (3), described one-sided responsive type capacitance probe (1) comprises driving pole plate (4), induction pole plate (5), shielding pole plate (6) and substrate (7), described driving pole plate (4) and induction pole plate (5) are positioned on the same surface of substrate (7), described shielding pole plate (6) is positioned on another surface of substrate (7), and described induction pole plate (5) and shielding pole plate (6) have equipotential.
2. a kind of non-insertion cultivation matrix water content sensor according to claim 1 is characterized in that: the capacitance measurement circuit on the described circuit main board (2) comprises power module, resonance modules, secondary frequency division module and lies prostrate converter frequently; Described power module is used for the power supply of dry cell power supply is converted to stable, the ripple-free voltage source that other electron device needs; Described resonance modules is for generation of the frequency signal of responsive cultivation matrix water cut; Described secondary frequency division module comprises prescalar and rearmounted frequency divider, wherein, prescalar is used for realizing presetting frequency division and level conversion function, and rearmounted frequency divider is high-speed asynchronous counter, is used for frequency division of the frequency to frequently lying prostrate in the treatable frequency of conversion circuit; Described frequency volt converter is used for making signal behind the frequency division of rearmounted frequency divider output with the d. c. voltage signal output of equivalence, and as signal of sensor.
3. a kind of non-insertion cultivation matrix water content sensor according to claim 1 and 2 is characterized in that: described driving pole plate (4), induction pole plate (5), shielding pole plate (6) surface all are coated with insulating layer coating.
4. a kind of non-insertion cultivation matrix water content sensor according to claim 1 and 2 is characterized in that: described induction pole plate (5) and the width of shielding pole plate (6) and the ratio of the spacing between them are got between the 0.8-1.
5. a kind of non-insertion cultivation matrix water content sensor according to claim 2 is characterized in that: the frequency size of described frequency signal is determined by the equivalent capacity size that with the cultivation matrix is the probe of medium.
6. a kind of non-insertion cultivation matrix water content sensor according to claim 1 and 2 is characterized in that: described capacitance measurement circuit comprises printed circuit board (PCB) and probe printed panel, and printed circuit board (PCB) is structure as a whole with the probe printed panel.
7. a kind of non-insertion cultivation matrix water content sensor according to claim 1 and 2 is characterized in that: the components and parts in the described capacitance measurement circuit all are positioned at the same side of shielding pole plate (6).
8. a kind of non-insertion cultivation matrix water content sensor according to claim 7 is characterized in that: described components and parts are all handled through waterproof and dampproof, insulation and the embedding of heat conductivility good electron waterproof glue.
9. peg model that is used for any described non-insertion cultivation matrix water content sensor of claim 1 to 8, it is characterized in that: described peg model is
Wherein,
UBe the sensor output voltage signal,
θBe the cultivation matrix water cut of correspondence, parameter
ε w ,
ε a Be the relative dielectric constant of water, air,
A, BValue can be definite by the output voltage of sensing in air and pure water,
U 2 Be sensor sensor output voltage in dried cultivation matrix,
βBe to mix specific inductive capacity parameter empirical value, its size and blending agent geometry, composition, electric field action directional correlation.
10. scaling method based on the non-insertion cultivation matrix water content sensor of model described in the claim 9, it is characterized in that: according in butt matter and any a bit known cultivation matrix water cut output voltage signal of sensor, determine the parameter in the peg model
β, determine calibration equation successively.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310147717.4A CN103207217B (en) | 2013-04-26 | 2013-04-26 | Non-plug-in water content sensor of culture substrate |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310147717.4A CN103207217B (en) | 2013-04-26 | 2013-04-26 | Non-plug-in water content sensor of culture substrate |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN103207217A true CN103207217A (en) | 2013-07-17 |
| CN103207217B CN103207217B (en) | 2015-04-22 |
Family
ID=48754504
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201310147717.4A Expired - Fee Related CN103207217B (en) | 2013-04-26 | 2013-04-26 | Non-plug-in water content sensor of culture substrate |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN103207217B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106018504A (en) * | 2016-05-09 | 2016-10-12 | 江苏大学 | PH detection double compensating method for soil matrix culture multi-parameter compound sensor |
| CN106290483A (en) * | 2016-07-29 | 2017-01-04 | 江苏大学 | A kind of super hydrophilic bionical water content of substrate sensor and preparation method thereof |
| CN114252130A (en) * | 2021-11-26 | 2022-03-29 | 深圳市纵维立方科技有限公司 | A liquid level detection circuit, automatic feeding device and 3D printer |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20100277185A1 (en) * | 2009-05-01 | 2010-11-04 | Spectrum Technologies, Inc. | Soil moisture sensor |
| CN102890104A (en) * | 2012-10-12 | 2013-01-23 | 江苏大学 | Culture substrate moisture capacitance transducer |
| CN102983851A (en) * | 2011-09-06 | 2013-03-20 | 胡夫·许尔斯贝克和福斯特有限及两合公司 | Capacitative sensor system |
-
2013
- 2013-04-26 CN CN201310147717.4A patent/CN103207217B/en not_active Expired - Fee Related
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20100277185A1 (en) * | 2009-05-01 | 2010-11-04 | Spectrum Technologies, Inc. | Soil moisture sensor |
| CN102983851A (en) * | 2011-09-06 | 2013-03-20 | 胡夫·许尔斯贝克和福斯特有限及两合公司 | Capacitative sensor system |
| CN102890104A (en) * | 2012-10-12 | 2013-01-23 | 江苏大学 | Culture substrate moisture capacitance transducer |
Non-Patent Citations (3)
| Title |
|---|
| 刘志刚等: "电介质型水分传感器测定栽培基质含水率的标定模型", 《农业工程学报》 * |
| 张宏等: "一种新型粮食水分数字传感器的设计", 《信阳师范学院学报(自然科学版)》 * |
| 郑志敏等: "用于非金属目标非接触位置检测的单片式电容传感器", 《清华大学学报(自然科学版)》 * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106018504A (en) * | 2016-05-09 | 2016-10-12 | 江苏大学 | PH detection double compensating method for soil matrix culture multi-parameter compound sensor |
| CN106290483A (en) * | 2016-07-29 | 2017-01-04 | 江苏大学 | A kind of super hydrophilic bionical water content of substrate sensor and preparation method thereof |
| CN106290483B (en) * | 2016-07-29 | 2018-12-14 | 江苏大学 | Super hydrophilic bionical water content of substrate sensor of one kind and preparation method thereof |
| CN114252130A (en) * | 2021-11-26 | 2022-03-29 | 深圳市纵维立方科技有限公司 | A liquid level detection circuit, automatic feeding device and 3D printer |
Also Published As
| Publication number | Publication date |
|---|---|
| CN103207217B (en) | 2015-04-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102890104B (en) | Culture substrate moisture capacitance transducer | |
| WO2017028535A1 (en) | Water level monitoring system based on internet of things and for water conservation and hydropower engineering | |
| CN103616056A (en) | Multipoint liquid level detection circuit | |
| CN206002050U (en) | A kind of frost zone thickness monitor device | |
| CN102997964A (en) | Soil multiparameter sensing measurement system | |
| CN103207217A (en) | Non-plug-in water content sensor of culture substrate and calibration method of sensor | |
| CN106771505A (en) | Single-phase overhead transmission line of electricity phase voltage method for self-calibrating based on series capacitance | |
| CN111693580A (en) | Capacitive soil moisture monitoring system and method | |
| CN108802105A (en) | A kind of section type soil moisture content monitor being adapted to agricultural irrigation | |
| CN102520025A (en) | Vertically intersected plane type soil water content sensor based on dielectric characteristic principle | |
| CN1719245A (en) | A method and sensor for synchronously measuring soil moisture and electrical conductivity in real time | |
| CN103424147A (en) | Soilless culture matrix multiparameter detector | |
| CN204789436U (en) | Vertical moisture automatic recorder of adjustable soil of integration | |
| CN106970268A (en) | Single-phase overhead transmission line of electricity phase voltage method for self-calibrating based on shunt capacitance | |
| CN205691088U (en) | A kind of frost penetration sensor | |
| CN205015307U (en) | Soil moisture sensor and flowerpot for flowerpot | |
| CN207396427U (en) | A kind of environment of internet of things measure and control device | |
| CN207280367U (en) | Mesh sensor | |
| CN205785332U (en) | Integration remote measurement paddy field moisture water-level instrumentation | |
| CN207074089U (en) | A kind of hydraulic energy recuperation cooling tower remote monitor device | |
| CN206832735U (en) | A kind of device of new measurement soil volumetric water content and nutrient solution concentration | |
| CN205228587U (en) | Electrodeless water level detection circuit of liquid tank | |
| CN207852480U (en) | A kind of NPO high voltage ceramic capacitors with dual redundant, small tolerance | |
| CN101975802A (en) | Embedded soil moisture content sensor and application thereof | |
| CN207600559U (en) | Capacitance type liquid level meter capable of shortening and self-adapting to medium |
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 | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20150422 Termination date: 20160426 |