CN101275923B - Gas sensor - Google Patents
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- CN101275923B CN101275923B CN200710038443XA CN200710038443A CN101275923B CN 101275923 B CN101275923 B CN 101275923B CN 200710038443X A CN200710038443X A CN 200710038443XA CN 200710038443 A CN200710038443 A CN 200710038443A CN 101275923 B CN101275923 B CN 101275923B
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
- G01N27/403—Cells and electrode assemblies
- G01N27/404—Cells with anode, cathode and cell electrolyte on the same side of a permeable membrane which separates them from the sample fluid, e.g. Clark-type oxygen sensors
Abstract
The present invention provides an oxygen sensor which comprises the following components: an electrolyte interlayer (110) which is provided with at least one through hole; a measuring electrode (112) which is arranged at one side of the electrolyte interlayer; and a counter electrode (114) which is arranged at the other side of the electrolyte interlayer. The dimension of at least one through hole satisfies the following relationship: A<liquid phase>/l<interlayer> <6.5*10<3>(A<entry>/l<entry>), wherein A<liquid phase> is the total sectional area of at least one through hole, l<interlayer> is the thickness of the through hole, A<entry> is the sectional area of the air inlet hole, and A<entry> is the length of the air inlet hole. The through hole can comprise a hydrophilic liquid-absorptionmaterial. The position is departed from the electric field formed by the measuring electrode and the counter electrode. The electrolyte interlayer can also be a hydrophilic micropore array formwork. In the oxygen sensor of the invention, the electrolyte interlayer structure which is provided with at least one through hole not only can be taken as an ion conductor for communicating the measuring electrode with the counter electrode but also can prevent the reverse diffusion of the oxygen. At the same time, the prepared oxygen sensor not only has excellent interference resistance but also has the advantage small volume.
Description
Technical field
The present invention relates to a kind of gas sensor, relate in particular to a kind of electrolysis-type gas sensor and a kind of electrolysis-type oxygen sensor.
Background technology
Electrochemical oxygen sensor is a kind of sensor that is widely used at present monitoring oxygen.U.S. patent of invention US4,132,616 have described a kind of oxygen sensor of galvanic cell type.In the work, oxygen is diffused into potential electrode by a pore, with the sub-combination of power and water there, reduction reaction occurs, and forms hydroxide ion.Hydroxide ion to electrode, with the lead electrode reaction, forms massicot, power and water by electrolyte flow.Hydroxide ion is in potential electrode with to the mobile electric current that forms between the electrode, and this electric current is directly proportional with the percent concentration of oxygen.Thus, can learn oxygen concentration by measuring electric current.
U.S. Patent application US2005/0034987 has described a kind of electrolysis-type oxygen sensor, and its critical component is electrolyte/electrode, specifically comprises solid electrolyte, potential electrode, to electrode and contrast electrode.Wherein, potential electrode is installed in a side of solid electrolyte, electrode and contrast electrode is installed in the opposite side of solid electrolyte.In the work, oxygen is diffused into potential electrode by a pore, is combined with hydrogen ion and the electronics of there, and reduction reaction occurs, and forms hydrone.Hydrone is penetrated into its opposite side by solid electrolyte.On the other hand, to the electrode place, hydrone is formed oxygen, hydrogen ion and electronics by electrolysis.In formed oxygen, hydrogen ion and electronics, oxygen is discharged from a venthole, and hydrogen ion moves to potential electrode by solid electrolyte, electronics then by an external circuit from electrode is reached potential electrode.Move to the hydrogen ion of potential electrode and be used for compensating hydrogen ion and the electronics that aforementioned reduction reaction consumes from the electronics to electrode, and form reduction current.Reduction current is directly proportional with the percent concentration of oxygen.
The patent No. is that ZL94107055.7, denomination of invention have also described a kind of electrolysis-type oxygen sensor for the Chinese invention patent of " solid polymer electrolyte, capillary type oxygen sensor ", has also described a kind ofly with rolled-on method the waterproof and breathable diffusion electrode to be fixed on preparation method on the solid polymer electrolyte.
In the electrolysis-type oxygen sensor, if at the oxygen that the electrode place is produced and from the reverse potential electrode that is diffused into of oxygen that venthole enters, can cause so measuring-signal to become large, thereby make the measurement result distortion.Therefore, this type of electrolysis-type oxygen sensor must satisfy following two normal running conditions: the one, and a plurality of electrodes communicate with each other through electrolyte, form ion channel in potential electrode with between to electrode, thereby carry out ion transport; The 2nd, be limited in the oxygen that the electrode place is produced and the reverse potential electrode that is diffused into of oxygen that enters from venthole, to guarantee that measuring-signal is accurate.
Present commercial electrolysis-type oxygen sensor, for example the electrolysis-type oxygen sensor of RAESYSTEMS company production adopts solid electrolyte Nafion film as electrolyte mostly.Solid electrolyte Nafion film can be communicated with potential electrode with to electrode as ion conductor, can prevent again the reverse diffusion of oxygen.Yet the conductivity of Nafion film depends on moisture, and is very responsive to humidity.So this type of all solid state electrolysis-type oxygen sensor is only applicable to use in a humid environment, and easy dehydration when using under the environment of drying can cause measurement result unstable.This so that its application be very restricted.Also have some electrolysis-type oxygen sensors to be immersed in the reservoir that acid electrolyte solution is housed with potential electrode with to electrode is all or part of, utilize acid electrolyte solution to be communicated with potential electrode with to electrode.Although this sensor is not easy dehydration, in order to guarantee under various modes of emplacements potential electrode and can both to touch acid electrolyte solution to electrode, must in reservoir, hold a lot of electrolyte solutions, cause sensor to have larger volume.
In fact, the various electrolysis-type gas sensors being used for measure gas concentrations all can meet the similar problem of stating.
Therefore, a kind of gas sensor with novel electrolyte separator layer need to be provided, this electrolyte separator layer can be communicated with potential electrode with to electrode as ion conductor, can prevent that again oxidation or reduction reaction are in the reverse potential electrode that is diffused into of gas that the electrode place is produced.
Also need to provide a kind of oxygen sensor with novel electrolyte separator layer, this electrolyte separator layer can be communicated with potential electrode with to electrode as ion conductor, can prevent again the reverse potential electrode that is diffused into of the gas at electrode place.
Also need to provide a kind of oxygen sensor with novel electrolyte separator layer, this oxygen sensor not only can get well but also volume is little by dry resistance.
Summary of the invention
To achieve these goals, according to one aspect of the present invention, provide a kind of oxygen sensor, it comprises:
Electrolyte separator layer, it comprises at least one through hole, has been full of a kind of electrolytic solution in the described through hole;
At least one potential electrode, it is positioned at a side of described electrolyte separator layer, and reduction reaction occurs in the oxygen that flows into by a blowhole at described potential electrode place, form hydrone;
At least one is to electrode, and it is positioned at the opposite side of described electrolyte separator layer, and described hydrone is by described through hole, and described oxidized to the electrode place, formation oxygen, hydrogen ion and electronics, formed oxygen pass through a venthole and discharge;
Wherein, the size of described at least one through hole satisfies following condition:
A
Liquid phase/ l
Interlayer＜6.5 * 10
3(A
Entrance/ l
Entrance)
Wherein, A
Liquid phaseThe total sectional area of described at least one through hole, l
InterlayerThe thickness of described through hole, A
EntranceBe the sectional area of described blowhole, l
EntranceLength for described blowhole.
In oxygen sensor of the present invention, can comprise a kind of hydrophilic imbibition material in the described through hole, the ratio of the total sectional area of described at least one through hole and the sectional area of described electrolyte separator layer is in 1%-50% scope.Preferably, the total sectional area of described at least one through hole and the ratio of the sectional area of described electrolyte separator layer are in 10%-15% scope.
Preferably, in oxygen sensor of the present invention, described at least one potential electrode of the position deviation of described through hole and described at least one to the formed electric field of electrode.
In oxygen sensor of the present invention, described electrolyte separator layer can also be a hydrophilic microwell array template, the ratio of the total sectional area of described microwell array and the sectional area of described electrolyte separator layer is in 0.1%-50% scope, and the porosity of described microwell array template is in 0.1%-15% scope.
Preferably, in oxygen sensor of the present invention, the size of described venthole satisfies following condition:
μ
Liquidl
Liquid layer/ d
Liquid layer 4μ
Gasl
Venthole/ d
Venthole 4
Wherein, μ
LiquidBe the viscosity of described electrolytic solution, l
Liquid layerBe the length of described through hole, d
Liquid layerBe the diameter of described through hole, μ
GasBe air viscosity, l
VentholeBe the length of described venthole, d
VentholeDiameter for described venthole.
Preferably, in oxygen sensor of the present invention, the resistance of the electrolytic solution in described at least one hole is less than 50 Ω.
In oxygen sensor of the present invention, described electrolytic solution can be sulfuric acid, and the length of described at least one through hole is less than 3000 times of the total sectional area of described at least one through hole.
Oxygen sensor of the present invention can also comprise the first hydrophilic imbibition material layer, and it is arranged between described electrolyte separator layer and the described potential electrode.Can also comprise the second hydrophilic imbibition material layer, it is arranged on described electrolyte separator layer and described between the electrode.Can also comprise a contrast electrode, the 3rd hydrophilic imbibition material layer, electrolyte separator layer and the 4th a hydrophilic imbibition material layer that adds, described additional electrolyte separator layer comprises at least one through hole, be full of described electrolytic solution in the described through hole, wherein said contrast electrode, the described the 3rd hydrophilic imbibition material layer, described additional electrolyte separator layer and the described the 4th hydrophilic imbibition material layer are arranged in the described the 3rd hydrophilic imbibition material layer and described between the electrode successively.
Oxygen sensor of the present invention can also comprise reservoir, and described reservoir is positioned at the described opposite side of described electrolyte separator layer, and comprises the material which can retain moisture that discharges moisture content.Can also comprise ring washer, it is arranged at least one side of described electrolyte separator layer both sides, is used for preventing that oxygen from leaking by described electrolyte separator layer.Can also comprise: the first oxygen permeable/waterproof membrane, it is positioned at described venthole near an end of described electrolyte separator layer, to oxygen permeable, and is used for preventing that moisture content from entering described venthole; Glass microfiber paper, it is used for helping to regulate the humidity of described electrolyte separator layer between described reservoir and described electrolyte separator layer; With the second oxygen permeable/waterproof membrane, it is positioned at described blowhole near an end of described electrolyte separator layer, to oxygen permeable, and is used for preventing that moisture content from entering described blowhole.
In oxygen sensor of the present invention, described electrolyte separator layer can be a macromolecule membrane, and the material of described macromolecule membrane is selected from polypropylene, polyester, Nafion and GEFC, and described hydrophilic imbibition material is the glass fibre that infiltrated with described electrolytic solution.In oxygen sensor of the present invention, the electrolyte separator layer structure with at least one through hole can be communicated with potential electrode with to electrode as ion conductor, can prevent again the reverse potential electrode that is diffused into of oxygen.Simultaneously, made oxygen sensor not only can get well but also volume is little by dry resistance.
According to another aspect of the present invention, a kind of gas sensor is provided, it comprises:
Electrolyte separator layer, it comprises at least one through hole, has been full of a kind of electrolytic solution in the described through hole;
At least one potential electrode, it is positioned at a side of described electrolyte separator layer, by a kind of reaction of gas in described potential electrode place generation reduction reaction and oxidation reaction of blowhole inflow;
At least one is to electrode, and it is positioned at the opposite side of described electrolyte separator layer, react at the described another kind that the electrode place is occured in reduction reaction and the oxidation reaction,
Wherein, the size of described at least one through hole and described blowhole is selected to and can prevents from being diffused into described potential electrode because of oxidation or reduction reaction the gas of described generation to the electrode place is reverse.
Description of drawings
Fig. 1 is a structural representation, illustration according to the electrolysis-type oxygen sensor of one embodiment of the invention.
Fig. 2 is a structural representation, illustration according to the electrode/interlayer of another embodiment of the present invention/electrode assemblie, this assembly is two electrode structures and has the electrolyte separator layer of single hole.
Fig. 3 is a structural representation, illustration according to the electrode/interlayer of further embodiment of this invention/electrode assemblie, this assembly is two electrode structures and the electrolyte separator layer with porous.
Fig. 4 is a structural representation, illustration according to the electrode/interlayer of yet another embodiment of the invention/electrode assemblie, this assembly is three-electrode structure and the electrolyte separator layer with porous.
Embodiment
Below in conjunction with accompanying drawing, preferred embodiment of the present invention is described.In the accompanying drawing, identical or corresponding part will use identical Reference numeral to represent.
I. oxygen sensor of the present invention
Fig. 1 shows three electrolysis type oxygen sensors according to one embodiment of the invention.As shown in Figure 1, oxygen sensor 100 comprises interlayer 110.One side of described interlayer 110 is potential electrode 112, and opposite side is to electrode 114 and contrast electrode 116.In the present embodiment, potential electrode 112 is negative electrode, is anode to electrode 114, and applies a negative bias between potential electrode and contrast electrode, and the current potential that is about to potential electrode is arranged to be lower than the current potential of contrast electrode.Shell 120 comprises housing 122 and cap 124, in they are encapsulated in described interlayer 110 and electrode 112,114 and 116.
In sensor 100, cap 124 consists of intake assembly with dustproof membrane 126 and restrictor 130.Wherein, dustproof membrane 126 is positioned on the cap 124, can be made by materials such as polypropylene or polyester, is used for preventing that dust and other particulate pollutant from entering sensor 100, and protection interlayer 110 and potential electrode 112 are not contaminated.Cap 124 is positioned on the restrictor 130 and has a pore 128, and pore 128 allows oxygen therefrom to pass through.Restrictor 130 has a diffusion pore 132, and pore 132 is communicated with pore 128 on the cap 124.
The critical component of sensor 100 is electrode/interlayer/electrode assemblies, and this assembly is arranged in operating room 140, comprises described interlayer 110 and electrode 112,114 and 116.Many factors, such as composition and the processing mode of interlayer 110, electrode 112,114 and 116 and interlayer 110 between technique for fixing and electrode 112, layout of 114 and 116 etc., all can affect the performance of electrode/interlayer/electrode assemblie.
At work, oxygen diffuses to potential electrode 112 by pore 132.At potential electrode 112 places, oxygen is caught from the electronics to electrode 114, and be combined from the hydrogen ion of interlayer 110, reduction reaction occurs, form hydrone.Reduction reaction is as shown in the formula shown in (1).
O
2+4H
++4e
-→2H
2O (1)
Formed hydrone infiltrates interlayer 110.
On the other hand, to electrode 114 places, hydrone is produced hydrogen ion and electronics by electrolysis.Electrolytic process is as shown in the formula shown in (2).
2H
2O→4H
++O
2+4e
- (2)
Because potential electrode 112 is set to negative electrode, will be set to anode to electrode 114, so but arrive potential electrode 112 at the hydrogen ion that electrode 114 places are produced by interlayer 110 diffusive migrations.Then also reach potential electrode 112 by an external circuit at the electronics that electrode 114 places are produced.In one embodiment, between potential electrode and contrast electrode, apply-negative bias of 0.6V by a potentiostatic circuit, for potential electrode 112 provides a negative potential.Under this current potential, potential electrode occurs suc as formula the reduction reaction shown in (1), forms simultaneously reduction current.Because reduction current depends on the wear rate of oxygen, so can determine the oxygen concentration at potential electrode 112 places by measuring reduction current.
In addition, be diffused into outside the sensor 100 by venthole 154 at the oxygen that electrode 114 places are produced.
Because reaction equation (1) and (2) are balances, so the reaction in the sensor 100 is the water that the water to the electrode place is converted to potential electrode 112 places, and the oxygen at potential electrode 112 places is converted to oxygen to electrode 114 places.Therefore, to be otherwise known as be " oxygen pump " to this oxygen sensor.In addition, electronics is discharging electrode 114 places, and 112 places catch in potential electrode.Hydrogen ion is from moving to potential electrode 112 to electrode 114 by interlayer 110.Interlayer 110 stops again the oxygen to electrode to diffuse into potential electrode.
II. the factor of electric current is measured in impact
As previously mentioned, in the electrolysis-type oxygen sensor, oxygen is diffused into potential electrode by a pore, is combined with hydrogen ion and the electronics of there, and reduction reaction occurs, and forms hydrone.Therefore, the speed that oxygen enters sensor is subjected to a diffusion barrier restriction, for example is subjected to the restriction in pore aperture.With this understanding, potential electrode is to work in so-called limiting current district.U.S. patent of invention US4,132,616 have illustrated the curve map of current density to polarized potential in its Fig. 1, and this is an oxygen electrode polarization curve.Dash area is the limiting current district among the figure, and under the limiting current condition, the oxygen concentration of electrode surface equals zero substantially.Therefore, limiting current is directly proportional with the flow of oxygen, and the flow of oxygen is the function of oxygen partial pressure in the gas to be measured, thereby can measure the concentration of airborne oxygen.For this reason, at the actual measurement negative electrode, oxygen electrode always applies a polarized potential that is positioned at limit of diffusion district, and this current potential will be lower than hydrogen-evolution overpotential, and this moment, the limiting current value was insensitive to current potential.Under this principle, the limiting current of the gas sensor of work will be determined by the diffusional resistance of control gas diffusion.Diffusional resistance refers to that gas arrives potential electrode and passes through a series of obstructions, comprises dustproof membrane, kapillary, waterproof and breathable electrode film (such as PTFE) etc.
The response current I of oxygen sensor
SignalGenerally comprise two parts electric current: the one, oxygen reaches the current i that potential electrode on cause by entrance through diffusion barrier through gas phase diffusion
Entrance, the 2nd, be diffused into the current i that potential electrode causes from the oxygen to electrode one side
To electrode, shown in equation (1).In order to guarantee the true of measuring-signal, need to eliminate as far as possible i
To electrodeAnd i
To electrodeThe electric current that may comprise three parts: the one, arrive the current i that potential electrode causes from the oxygen to electrode one side through gas phase diffusion
Gas phaseThe 2nd, arrive the current i that potential electrode causes from the oxygen to electrode one side through the Liquid Penetrant diffusion
Liquid phaseThe 3rd, arrive the current i that potential electrode causes from the oxygen to electrode one side through the solid diffusion
Solid phase, shown in equation (2).
I
Signal=i
Entrance+ i
To electrode(1)
i
To electrode=i
Gas phase+ i
Liquid phase+ i
Solid phase(2)
With equation (2) substitution equation (1), obtain:
I
Signal=i
Entrance+ i
Gas phase+ i
Liquid phase+ i
Solid phase(3)
In addition, limiting diffusion current is:
i＝nFADC/l (4)
Wherein, n is electron number, and F is Faraday constant, and A is the area of mass transfer, and D is the coefficient of diffusion (m of oxygen
2/ s), C is the concentration of oxygen, l be oxygen transmission the distance of process.
At first, the current i that causes for the oxygen that enters through pore from the sensor porch
Entrance, according to equation (4), i
EntranceFor:
i
Entrance=nFA
EntranceD
Oxygen is in gas phaseC/l
Entrance(5)
Wherein, A
EntranceSectional area for the porch pore; l
EntranceCan be approximately the length of porch pore.For oxygen reduction reaction, n=4, F=96500Cmol
-1In addition, at normal temperatures and pressures, airborne oxygen concentration C=0.27kgm
-3Therefore, can obtain behind the substitution equation (5):
i
Entrance=4 * 96500 * 0.27A
EntranceD
Oxygen is in gas phase/ l
Entrance
=10
5A
EntranceD
Oxygen is in gas phase/ l
Entrance(6)
Secondly, for the current i that causes from the oxygen to electrode one side
Gas phase, i
Liquid phaseAnd i
Solid phase, according to equation (4),
i
Gas phase=nFA
LeakD
Oxygen is in gas phaseC/l
Interlayer
=10
5A
LeakD
Oxygen is in gas phase/ l
Interlayer(7)
A wherein
LeakThat oxygen is leaked the area that transmits, l in the gas phase mode around electrolyte separator layer
InterlayerBe approximately the thickness of electrolyte separator layer;
i
Solid phase=nFA
SolidD
Oxygen is in solid phaseC
Solid phase/ l
Interlayer
=nFA
SolidD
Oxygen is in solid phaseS
Solid phaseP
Pressure/ l
Interlayer
=3.86 * 10
5A
SolidD
Oxygen is in solid phaseS
Solid phaseP
Pressure/ l
Interlayer(8)
=3.86 * 10
5A
SolidP
Infiltration coefficientP
Pressure/ l
Interlayer(9)
Wherein, A
SolidThe area of solid electrolyte, the concentration of ordinary dissolution C of oxygen in solid electrolyte
Solid phase(kgm
-3)=S
Solid phaseP
Pressure, S
Solid phaseThe solubility factor (kgm of oxygen in solid electrolyte
-3Pa
-1), P
PressureThe dividing potential drop (Pa) of oxygen, P
Infiltration coefficientRefer to the infiltration coefficient of oxygen in solid electrolyte; In like manner,
i
Liquid phase=nFA
Liquid phaseD
Oxygen is in liquid phaseS
Liquid phaseP
Pressure/ l
Interlayer
=3.86 * 10
5A
LiquidD
Oxygen is in liquid phaseS
Liquid phaseP
Pressure/ l
Interlayer(10)
A wherein
Liquid phaseIt is the electrolytical sectional area of liquid phase; S
Liquid phaseThe solubility factor of oxygen in liquid electrolyte.
1. solid electrolyte interlayer
Below, we study first the situation of solid electrolyte interlayer.At this moment, can not consider i
Liquid phase, equation (3) is reduced to:
I
Signal=i
Entrance+ i
Gas phase+ i
Solid phase(11)
With equation (6), (7) and (9) substitution equatioies (11) obtain:
I
Signal=10
5A
EntranceD
Oxygen is in gas phase/ l
Entrance+ 10
5A
LeakD
Oxygen is in gas phase/ l
Interlayer+ 3.86 * 10
5A
Solid phaseP
Infiltration coefficientP
Pressure/ l
Interlayer(12)
Because oxygen is such as the infiltration coefficient P in the solid electrolyte interlayers such as Nafion
Infiltration coefficientBe 10
-16Kgm*m
-2s
-1Pa
-1The aerial diffusion coefficient D of oxygen
Oxygen is in gas phaseBe 10
-5m
2/ s; And at normal temperatures and pressures, the dividing potential drop P of oxygen
PressureApproximately be 10
4Pa, so behind the substitution equation (12), can obtain:
I
Signal=10
5A
Entrance10
-5/ l
Entrance+ 10
5A
Leak10
-5/ l
Interlayer+ 3.86 * 10
5A
Solid phase10
-1610
4/ l
Interlayer
=A
Entrance/ l
Entrance+ A
Leak/ l
Interlayer+ 3.86 * 10
-7A
Solid phase/ l
Interlayer(13)
For solid electrolyte Nafion, the thickness l of Nafion-117
InterlayerBe 4 * 10
-4M, the sectional area A of use Nafion-117 in the 4R sensor
Solid phaseBe about 8 * 10
-5m
2(10 millimeters of diameters), the sectional area A of sensor gas access pore
EntranceBe about 8 * 10
-9m
2(0.1 millimeter of diameter), the length l of pore
EntranceBe about 10
-3M.Thus, equation (13) becomes:
I
Signal=8 * 10
-9/ 10
-3+ A
Leak/ l
Interlayer+ 3.86 * 10
-7* 8 * 10
-5/ (4 * 10
-4)
=8 * 10
-6+ A
Leak/ l
Interlayer+ 7.7 * 10
-8
By following formula as can be known, front two numerical value of the 3rd numeric ratio are wanted little 2 orders of magnitude.Therefore, can ignore for the 3rd.In addition, because i
Solid phaseBe far smaller than i
Gas phaseSo, for the oxygen sensor of solid electrolyte as interlayer, as long as avoid as possible oxygen around the solid electrolyte interlayer through gas phase diffusion reach potential electrode just can basically guarantee measuring-signal truly.In the prior art, usually above the interlayer and/or below ring washer is set, to prevent from the oxygen at electrode place is reached potential electrode through gas phase diffusion around the solid electrolyte interlayer.
2. the interlayer that comprises liquid electrolyte
Next, we have the situation that is full of the interlayer of liquid in a hole and the hole at least at research, and the diameter of its mesopore is d, and the degree of depth in hole or the thickness of interlayer are l.At this moment, can not consider i
Solid phase, equation (3) is reduced to:
I
Signal=i
Entrance+ i
Gas phase+ i
Liquid phase(14)
With equation (6), (7) and (10) substitution equatioies (14) obtain:
I
Signal=10
5A
EntranceD
Oxygen is in gas phase/ l
Entrance+ 10
5A
LeakD
Oxygen is in gas phase/ l
Interlayer+ 3.86 * 10
5A
Liquid phaseD
Oxygen is in gas phaseS
Liquid phaseP
Pressure/ l
Interlayer(15)
The diffusion coefficient D of oxygen in aqueous solution
Oxygen is in liquid phaseBe about 10
-9m
2/ s, solubility factor S
Liquid phaseBe about 4 * 10
-7Kgm
-3Pa
-1, and at normal temperatures and pressures, the dividing potential drop P of oxygen
PressureApproximately be 10
4Pa.With these data substitution equatioies (15), obtain:
I
Signal=10
5A
Entrance* 10
-5/ 1
Entrance+ 10
5A
Leak* 10
-5/ l
Interlayer+ 3.86 * 10
5A
Liquid phase* 10
-9* 4 * 10
-7* 10
4/ l
Interlayer
=A
Entrance/ l
Entrance+ A
Leak/ l
Interlayer+ 1.54 * 10
-6* A
Liquid phase/ l
Interlayer(16)
(a) about the 3rd A in the formula (16)
Liquid phase/ l
Interlayer
If A
Entrance/ l
EntranceCan be than 1.54 * 10
-6A
Liquid phase/ l
InterlayerLarge two more than the order of magnitude, i so
Liquid phaseImpact can ignore.At this moment, as long as avoid oxygen around the liquid electrolyte interlayer, to arrive potential electrode through gas phase diffusion, just basically can guarantee the true of measuring-signal.Thus, need
(A
Entrance/ l
Entrance)/(1.54 * 10
-6* A
Liquid phase/ l
Interlayer) 100
(A
Entrance/ l
Entrance)/(A
Liquid phase/ l
Interlayer) 1.54 * 10
-4
A
Liquid phase/ l
Interlayer＜(A
Entrance/ l
Entrance) 6.5〉10
3(17)
That is to say, work as A
Liquid phase/ l
InterlayerLess than A
Entrance/ l
Entrance6.5 * 10
3Times the time, the impact of i liquid phase can be ignored.This is the principle that will consider during sensor in design, namely selects the size in hole on the thickness of interlayer and the interlayer according to the size of entrance pore.
The sectional area A of sensor gas access pore
EntranceBe about 8 * 10
-9m
2(0.1 millimeter of diameter), the length l of pore
EntranceBe about 10
-3M.A so
Entrance/ l
Entrance=8 * 10
-6Thereby, A
Liquid phase/ l
Interlayer＜0.052.That is, the area of liquid electrolyte interlayer need be less than 0.052 times of compartment thickness.
Example 1: for the 4R sensor, its xsect is 8 * 10
-5m
2, when liquid electrolyte is ratio that the hole sectional area of interlayer occupies sensor cross-section when being 50%, A
Liquid phase=4 * 10
-5m
2, utilize formula (17) A
Liquid phase/ l
Interlayer＜(A
Entrance/ l
Entrance) 6.5 * 10
3Calculate
4 * 10
-5/ l
Interlayer＜8 * 10
-6* 6.5 * 10
3
As long as l
Interlayer7.7 * 10
-4M, namely the thickness of liquid electrolyte just can be ignored the oxygen that is diffused into potential electrode by liquid layer greater than 0.77 millimeter.
Example 2: for the 4R sensor, its xsect is 8 * 10
-5m
2, when liquid electrolyte is ratio that the hole sectional area of interlayer occupies sensor cross-section when being 1%, utilize formula (17) to calculate
0.01 * 8 * 10
-5/ l
Interlayer＜8 * 10
-6* 6.5 * 10
3
As long as l
Interlayer1.5 * 10
-5M, namely the thickness of liquid electrolyte just can be ignored the oxygen that is diffused into potential electrode by liquid layer greater than 15 microns.
(b) about second A in the formula (16)
Leak/ l
Interlayer
In addition, also need to consider from the oxygen of electrode one side is penetrated liquid layer with the form of bubble and arrive the situation of potential electrode.Generally speaking, if liquid layer to the resistance of gas greater than the gaseous tension to electrode one side, gas just can not penetrate liquid layer and arrive potential electrode, and relevant with the resistance of venthole to the accumulation of the gaseous tension of electrode one side.If liquid layer, just can not penetrate liquid layer to the gas of electrode one side so and arrive potential electrode greater than the resistance of venthole to gas the resistance of gas.
Below, we will study as preventing that oxygen from penetrating liquid layer with bubble form and arriving potential electrode, the condition that venthole should satisfy.
With mobile Laminar Flow [" fluid machinery ", 2000,28 (2) 38-39], the flow resistance R of venthole of being approximately in the pore
VentholeFor:
R
Venthole=128 μ
Gasl
Venthole/ π d
Venthole 4(18)
Wherein, l
VentholeBe the length of venthole, d
VentholeBe the diameter of venthole, μ
GasBe air viscosity.
The flow resistance R of liquid electrolyte interlayer
Fluid passageFor:
R
Fluid passage=128 μ
Liquidl
Liquid layer/ π d
Liquid layer 4(19)
Wherein, l
Liquid layerBe the length of liquid layer, d
Liquid layerBe the diameter of liquid layer, u
LiquidBe liquid viscosity.
Work as R
Fluid passageR
VentholeThe time, can ignore oxygen and penetrate the impact that liquid layer is produced with bubble form.Substitution equation (18) and (19) obtain:
μ
Liquidl
Liquid layer/ d
Liquid layer 4μ
Gasl
Venthole/ d
Venthole 4(20)
Suppose to adopt sulfuric acid as liquid electrolyte.At this moment, because the viscosity, mu of air
Gas=1.8 * 10
-5Pas, the viscosity, mu of sulfuric acid
LiquidBe about 1.2 * 10
-2Pas,
l
Liquid layer/ d
Liquid layer 41.5 * 10
-3* l
Venthole/ d
Venthole 4
Example 1: under a kind of extreme case, if the hole sectional area is the liquid layer exposed area account for sensor section long-pending 50%, namely the diameter in hole is 7 millimeters, liquid layer thickness is 0.77 millimeter, so
l
Venthole/ d
Venthole 4＜2.1 * 10
8
The length of supposing venthole is 1 millimeter, and the diameter of venthole need to be greater than 1.5 millimeters.
Example 2: under another extreme case, if the hole sectional area is the liquid layer exposed area account for sensor section long-pending 1%, when namely the diameter in the hole on the interlayer is 1 millimeter, during 15 microns of liquid layer thickness,
l
Venthole/ d
Venthole 4＜10
10
At this moment, when the length of venthole is 1 millimeter, the diameter of venthole need to be greater than 0.56 millimeter.
This shows, when in oxygen sensor, using liquid electrolyte as electrolyte separator layer, need to consider that the diameter of venthole is on the impact of sensor performance.
(c) liquid layer resistance is on the impact of sensor performance
In addition, when using liquid electrolyte as electrolyte separator layer, we need to consider whether liquid layer resistance can satisfy the needs of sensor performance.
Generally speaking, sensor liquid resistance size can affect the control of Electric potentials precision of sensor measurement electrode and the response time of sensor.But, because the working current of sensor is generally less, so neither be very harsh to the requirement of resistance.For example, as R＜50 Ω, the response current size is 0.5 MAH, and it is on namely 25 millivolts of the impacts of control of Electric potentials precision.For the oxygen sensor that is in limit diffusion control district, this equipotential fluctuation is on the almost not impact of measuring-signal of sensor.
The following relation of liquid resistance size general satisfaction: R=ρ 1/A.For the 6M sulfuric acid solution, its conductivity G=60 Ω
-1m
-1, ρ=1/G.When requiring R＜50 Ω, R/ ρ＜3000, i.e. l/A＜3000.This explanation when liquid layer thickness during less than 3000 times of liquid layer areas, can guarantee liquid resistance less than 50 Ω, thereby on the almost not impact of measuring-signal of sensor.
From the above analysis, when oxygen sensor uses liquid electrolyte as electrolyte separator layer, can not consider that basically oxygen is by being dissolved in the liquid layer and then being diffused into the impact that potential electrode produces.In order to prevent needing size and the suitable selection liquid electrolyte of design liquid electrolyte interlayer and venthole from the oxygen of the electrode one side form with bubble is penetrated liquid layer and arrives potential electrode, it is satisfied: μ
Liquidl
Liquid layer/ d
Liquid layer 4μ
Gasl
Venthole/ d
Venthole 4In addition, in order to reduce the sensor liquid resistance to the impact of the control of Electric potentials precision of sensor measurement electrode, wish liquid resistance R＜50 Ω.In a word, when oxygen sensor used liquid electrolyte as electrolyte separator layer, key will stop the oxygen that is diffused into potential electrode with the gas phase form.As long as guarantee fluid-tight, do not have gas passage, and venthole is unobstructed, just can eliminate oxygen and penetrate the impact that liquid layer is produced with bubble form.
III. electrode/interlayer of the present invention/electrode assemblie
Embodiment 1: the electrolyte separator layer with single hole
Fig. 2 shows electrode/interlayer according to one embodiment of the invention/electrode assemblie 240.This assembly is the assembly of two electrodes, comprises interlayer 210, potential electrode 112 and to electrode 114.Potential electrode 112 is positioned at a side of interlayer 210, electrode 114 is positioned at the opposite side of interlayer 210.Interlayer 210 can be the macromolecule membrane that is equipped with a hole 214, and such as polypropylene, polyester, Nafion, GEFC etc. filled up hydrophilic imbibition material in the hole 214.Preferably, the first hydrophilic imbibition material layer 156 can be set between interlayer 210 and potential electrode 112, the second hydrophilic imbibition material layer 156 is set at interlayer 210 with between to electrode 114.Hydrophilic imbibition material in the first and second hydrophilic imbibition material layers 156 and the hole 214 can be the glass fibre of using the solution impregnation such as the acid electrolyte such as sulfuric acid and phosphoric acid to cross.The acid electrolyte solution that the first and second hydrophilic imbibition material layers 156 will be laid in the hydrophilic imbibition material 152 of reservoir 150 by capillary action is introduced in the described hole 214, and the hole is communicated with up and down.
In the electrode/interlayer of the present embodiment/electrode structure, the interlayer 210 that is equipped with a hole can play the ion conducting, stop from the effect to the oxygen diffusion of electrode one side.Guaranteeing that the sectional area in hole 214 is less, under the environment of drying, more is not easy to produce gas passage in the hole under the unimpeded prerequisite of ion channel.But,, and infiltrating with potential electrode with to electrode acid electrolyte solution inlet hole 214 from reservoir 150 for rapidly, the area in hole 214 is the bigger the better.Consider this two factors, and in conjunction with guaranteeing the normal actual needs that uses of sensor, the sectional area that the sectional area in hole accounts for sensor is preferably 1%～50%, is preferably in 10～15% scope.
For example, for the 4R sensor, suppose the sectional area A of oxygen intake pore
EntranceBe about 8 * 10
-9m
2(0.1 millimeter of diameter), the length l of pore
EntranceBe about 10
-3M, the xsect of 4R sensor are 8 * 10
-5m
2When the ratio that occupies sensor cross-section when the hole sectional area on the interlayer is 50%, A
Liquid phase=4 * 10
-5m
2Utilize formula (17) A
Liquid phase/ l
Interlayer＜(A
Entrance/ l
Entrance) 6.5 * 10
3Can know, as long as l
Interlayer7.7 * 10
-4M, namely the length in the hole of interlayer is greater than 0.77 millimeter, and the oxygen that just can ignore electrode 114 1 sides is diffused into the impact that potential electrode 112 produces by the sour electrolytic solution in the hole 214.In addition, utilize formula (20) to know, if adopt sulfuric acid as electrolyte solution, the length of venthole is 1 millimeter, the diameter that needs only venthole so is greater than 1.5 millimeters, and the gas that just can ignore electrode one side is diffused into the impact that potential electrode 112 is produced with the sour electrolytic solution in the bubble form through hole 214.
And for example, for the 4R sensor, suppose the sectional area A of oxygen intake pore
EntranceBe about 8 * 10
-9m
2(0.1 millimeter of diameter), the length l of pore
EntranceBe about 10
-3M, the xsect of 4R sensor are 8 * 10
-5m
2When the ratio that occupies sensor cross-section when the hole sectional area on the interlayer is 1%, utilize formula (17) to know, as long as l
Interlayer1.5 * 10
-5M, namely the length in the hole of interlayer just can be ignored oxygen and be diffused into the impact that potential electrode produces by sour electrolytic solution greater than 15 micron.In addition, utilize formula (20) to know, if adopt sulfuric acid as electrolyte solution, the length of venthole is 1 millimeter, the diameter that needs only venthole so is greater than 0.56 millimeter, and the gas that just can ignore electrode one side is diffused into the impact that potential electrode 112 is produced with the sour electrolytic solution in the bubble form through hole 214.
If make the position deviation potential electrode 112 in hole 214 and to electrode 114 formed electric fields, so actual oxygen channel is increased.Correspondingly, the thickness l of interlayer
InterlayerCan do littlely.
Experiment is found, if use merely hydrophilic fiber web layer imbibition material such as glass fibre etc. to fix acid electrolyte solution, and fix acid electrolyte solution without solid materials such as macromolecule membrane such as polypropylene, tygon, Nafion and GEFC, under dry environment, oxygen sensor is easy to dry out so.When the acid electrolyte solution that infiltrates in the hydrophilic fiber web layer reduces, because hydrophilic fiber web layer is loose, can forms the porous air flue, thereby make the measuring-signal distortion of sensor.
Embodiment 2: the electrolyte separator layer with porous
For the electrolyte separator layer of above-mentioned single hole, the sectional area that hole area accounts for sensor is larger, and the difficulty of acid electrolyte solution is just larger in the fixed orifice.For this reason, the inventor has designed the electrolyte separator layer of porous.
1. the assembly of two electrodes
Fig. 3 shows electrode/interlayer according to another embodiment of the present invention/electrode assemblie 340.Similar to last embodiment, this assembly also is the assembly of two electrodes, comprises interlayer 310, potential electrode 112 and to electrode 114.Potential electrode 112 is positioned at a side of interlayer 310, electrode 114 is positioned at the opposite side of interlayer 310.Interlayer 310 can be the macromolecule membrane that is equipped with a plurality of holes 314, and such as polypropylene, polyester, Nafion, GEFC etc. filled up hydrophilic imbibition material in a plurality of holes 314.Preferably, the first hydrophilic imbibition material layer 156 can be set between interlayer 310 and potential electrode 112, the second hydrophilic imbibition material layer 156 is set at interlayer 310 with between to electrode 114.Hydrophilic imbibition material in the first and second hydrophilic imbibition material layers 156 and a plurality of hole 314 can be the glass fibre of using the solution impregnation such as the acid electrolyte such as sulfuric acid and phosphoric acid to cross.The acid electrolyte solution that the first and second hydrophilic imbibition material layers 156 will be laid in the hydrophilic imbibition material 152 of reservoir 150 by capillary action is introduced in a plurality of holes 314, and the hole is communicated with up and down.
Described a plurality of hole 314 can be on interlayer 310 arbitrary position.Preferably, make these holes 214 depart from potential electrode 112 with to electrode 114 formed electric fields.The shape in hole also can be arbitrarily, for example circular, oval, square etc. can.
In the electrode/interlayer of the present embodiment/electrode structure, the interlayer 310 that is equipped with a plurality of holes can play the ion conducting, stop from the effect to the oxygen diffusion of electrode one side.
Compare with the electrolyte separator layer with single hole, the electrolyte separator layer that is equipped with a plurality of holes 314 has increased total hole area.Like this, easier capillary action by means of hydrophilic imbibition material with in the electrolyte solution inlet hole 314 in the reservoir, and is infiltrated with potential electrode with to electrode, make oxygen sensor enter fast duty.On the other hand, under the condition with equal total hole area, the number in hole 314 is more, and the sectional area in each hole is less.Like this, the acid electrolyte in the fixed orifice under the environment of drying, is not easy to produce gas passage in the hole better.The acid electrolyte solution that is filled in the hole forms ion channel in potential electrode with between to electrode, fluid-tight in the hole and the solid portion of interlayer up and down two air chambers separate, prevention is diffused into potential electrode to the oxygen of electrode one side, thereby has guaranteed the accurate of measuring-signal.In addition, under the condition with equal total hole area, the number in hole is more, also can reduce the requirement of venthole.For example, when accounting for sensor section, total hole sectional area (being the liquid layer exposed area) amasss 8 * 10
-5m
250%, and liquid layer thickness is when being 0.77 millimeter, if only have a hole, the diameter in hole is about 7 millimeters on the interlayer so, the length of supposing again venthole is 1 millimeter, the diameter of venthole need to be greater than 1.5 millimeters so.If but open 4 holes on the interlayer, the diameter in interlayer hole is about 3.6 millimeters so, and the length of supposing again venthole is 1 millimeter, so basis
4l
Liquid layer/ d
Liquid layer 41.5 * 10
-3* l
Venthole/ d
Venthole 4
Can learn, the diameter of venthole need to be greater than 0.53 millimeter.This shows, under the condition with equal total hole area, the number in hole is more, also can reduce the requirement of venthole.
2. three electrode assembly
Fig. 4 shows electrode/interlayer according to further embodiment of this invention/electrode assemblie 440.This assembly is a three electrode assembly, comprises the first interlayer 410, the second interlayer 412, potential electrode 112, to electrode 114 and contrast electrode 116.Potential electrode 112 is positioned at the first side of the first interlayer 410, and contrast electrode 116 is positioned at the second side of the second interlayer 412 to electrode 114 between the first side of the second side of the first interlayer 410 and the second interlayer 412.The first interlayer 410 and the second interlayer 412 can be the macromolecule membranes that is equipped with a plurality of holes 414, and such as polypropylene, polyester, Nafion, GEFC etc. filled up hydrophilic imbibition material in a plurality of holes 414.Preferably, the first hydrophilic imbibition material layer 156 can be set between potential electrode 112 and the first interlayer 410, the second hydrophilic imbibition material layer 156 is set between the first interlayer 410 and contrast electrode 116, the 3rd hydrophilic imbibition material layer 156 is set between contrast electrode 116 and the second interlayer 412, the second interlayer 412 and and to electrode 114 between the 4th hydrophilic imbibition material layer 156 is set.Hydrophilic imbibition material in the first, second, third and the 4th hydrophilic imbibition material layer 156 and a plurality of hole 314 can be the glass fibre of using the solution impregnation such as the acid electrolyte such as sulfuric acid and phosphoric acid to cross.The acid electrolyte solution that the first, second, third and the 4th hydrophilic imbibition material layer 156 will be laid in the hydrophilic imbibition material 152 of reservoir 150 by capillary action is introduced in a plurality of holes 414, and the hole is communicated with up and down.
Described a plurality of hole 414 can be on the first and second interlayers arbitrary position.Preferably, make these holes 414 depart from potential electrode 112 with to electrode 114 formed electric fields.The shape in hole also can be arbitrarily, for example circular, oval, square etc. can.
In the electrode/interlayer of the present embodiment/electrode structure, the interlayer 310 that is equipped with a plurality of holes can play the ion conducting, stop from the effect to the oxygen diffusion of electrode one side.
As everyone knows, contrast electrode 116 plays the effect of stable potential, and the measuring-signal that is conducive to sensor is more accurate.In the present embodiment, contrast electrode 116 is placed in the centre, and a plurality of holes is arranged in the outside of interlayer.This will be conducive to reduce and detect gas and interference gas to the impact of the current potential of contrast electrode, guarantee that reference potential does not drift about.
Embodiment 3: the electrolyte separator layer of microwell array
In the present embodiment, electrolyte separator layer adopts the microwell array template of hydrophilic track etching polycarbonate, and both sides can be fixed with hydrophilic fiber web layer.Hydrophilic fiber web layer sucks acid electrolyte solution in the microwell array of template soon by capillary action, is communicated with potential electrode with to electrode.In principle, as long as the microwell array template is hydrophilic, resist chemical (namely stable in concentrated acid), and stable performance in-40～65 ℃ working sensor scope all can use.
The thickness of array mould plate can be in 6～11 microns scope.For the template of different-thickness, can select different micropore sizes.According to the sealing liquid needs, micropore size can be in the scope of 0.015-1 micron.
The pore of microwell array template is less, and capillary action is more remarkable, and the ability that keeps aqueous solution is stronger, thereby more easily guarantees fluid-tight.In the situation that microwell array template complete wetting, the porosity of array mould plate is less, and the effect of isolated gas is better.Better, porosity is not more than 15%.But in order to guarantee the ion conducting, porosity preferably is not less than 0.1%.
In the present embodiment, owing to use the microwell array interlayer to fix electrolytic solution, so wider to the designing requirement of venthole.For thickness in 6～11 micrometer ranges, the array mould plate of micropore size in the 0.015-1 micrometer range, porosity＜15%, if use sulfuric acid as electrolyte solution, and the Design of length of venthole is 1 millimeter, and the diameter of venthole just can stop that greater than 0.3 millimeter the oxygen to electrode one side penetrates liquid layer with bubble form so.This is highly beneficial for doing Miniature Sensor.
In addition, for hydrophilic microwell array interlayer, because the aperture is little, imbibition ability is strong, can widen to 0.1%～50% therefore total hole area accounts for the long-pending ratio of sensor section, thereby can select how applicable material.IV. gas sensor of the present invention
The structure of above-mentioned theory derivation for oxygen sensor and each embodiment can be generalized to the gas sensor of other electrolysis-types.For example, can be according to different gas to be measured, select the size of through hole and blowhole, thus prevent because of oxidation or reduction reaction in the reverse potential electrode that is diffused into of gas that the electrode place is produced.Can also select the size of pore according to different electrolyte solutions, thereby prevent from the gas that the electrode place produces is penetrated liquid layer with bubble form.
Although more than described preferred embodiment of the present invention, the present invention is not limited only to this.Those skilled in the art can carry out various variations and change on basis described above.Do not break away from the various changes of invention spirit and change and all should drop within protection scope of the present invention.The protection domain of invention is limited by appending claims.
Claims (17)
1. oxygen sensor, it comprises:
Electrolyte separator layer (110), it comprises at least one through hole (214,314,414), has been full of a kind of electrolytic solution in the described through hole;
At least one potential electrode (112), it is positioned at a side of described electrolyte separator layer, and reduction reaction occurs in the oxygen that flows into by a blowhole at described potential electrode place, form hydrone;
At least one is to electrode (114), and it is positioned at the opposite side of described electrolyte separator layer, and described hydrone is by described through hole, and described oxidized to the electrode place, formation oxygen, hydrogen ion and electronics, formed oxygen pass through a venthole and discharge;
Wherein, the size of described at least one through hole satisfies following condition:
A
Liquid phase/ l
Interlayer＜6.5 * 10
3(A
Entrance/ l
Entrance)
Wherein, A
Liquid phaseTotal cross-sectional area of described at least one through hole, l
InterlayerThe thickness of described through hole, A
EntranceBe the cross-sectional area of described blowhole, l
EntranceLength for described blowhole.
2. oxygen sensor as claimed in claim 1 is characterized in that, comprises a kind of hydrophilic imbibition material in the described through hole, and the ratio of total cross-sectional area of described at least one through hole and the cross-sectional area of described electrolyte separator layer is in the scope of 1%-50%.
3. oxygen sensor as claimed in claim 2 is characterized in that, the ratio of total cross-sectional area of described at least one through hole and the cross-sectional area of described electrolyte separator layer is in the scope of 10%-15%.
4. oxygen sensor as claimed in claim 2 is characterized in that, described at least one potential electrode of the position deviation of described through hole and described at least one to the formed electric field of electrode.
5. oxygen sensor as claimed in claim 3 is characterized in that, described at least one potential electrode of the position deviation of described through hole and described at least one to the formed electric field of electrode.
6. oxygen sensor as claimed in claim 1, it is characterized in that, described electrolyte separator layer is a hydrophilic microwell array template, the ratio of total cross-sectional area of described microwell array and the cross-sectional area of described electrolyte separator layer is in the scope of 0.1%-50%, and the porosity of described microwell array template is in the scope of 0.1%-15%.
7. such as any one described oxygen sensor among the claim 4-6, it is characterized in that, the size of described venthole satisfies following condition:
μ
Liquidl
Liquid layer/ d
Liquid layer 4＞μ
Gasl
Venthole/ d
Venthole 4
Wherein, μ
LiquidBe the viscosity of described electrolytic solution, l
Liquid layerBe the length of described through hole, d
Liquid layerBe the diameter of described through hole, μ
GasBe air viscosity, l
VentholeBe the length of described venthole, d
VentholeDiameter for described venthole.
8. oxygen sensor as claimed in claim 7 is characterized in that, the resistance of the electrolytic solution in described at least one through hole is less than 50 Ω.
9. oxygen sensor as claimed in claim 8, it is characterized in that, described electrolytic solution is sulfuric acid, and the numerical value of the length of described at least one through hole is less than 3000 times of the numerical value of total cross-sectional area of described at least one through hole, the unit of wherein said length is m, and the unit of described total cross-sectional area is m
2
10. such as any one described oxygen sensor among the claim 4-6, it is characterized in that, also comprise the first hydrophilic imbibition material layer (156), it is arranged between described electrolyte separator layer and the described potential electrode.
11. oxygen sensor as claimed in claim 10 is characterized in that, also comprises the second hydrophilic imbibition material layer (156), it is arranged on described electrolyte separator layer and described between the electrode.
12. oxygen sensor as claimed in claim 11, it is characterized in that, also comprise a contrast electrode (116), the 3rd hydrophilic imbibition material layer (156), one additional electrolyte separator layer (412) and the 4th hydrophilic imbibition material layer (156), described additional electrolyte separator layer comprises at least one through hole (414), be full of described electrolytic solution in the described through hole, wherein said contrast electrode, the described the 3rd hydrophilic imbibition material layer, described additional electrolyte separator layer and the described the 4th hydrophilic imbibition material layer (156) are arranged in the described the 3rd hydrophilic imbibition material layer and described between the electrode successively.
13. such as any one described oxygen sensor among the claim 4-6, it is characterized in that, also comprise:
Reservoir (150), described reservoir are positioned at the described opposite side of described electrolyte separator layer, and comprise the material which can retain moisture (152) that discharges moisture content.
14. oxygen sensor as claimed in claim 13 is characterized in that, also comprises ring washer (146), it is arranged at least one side of described electrolyte separator layer both sides, is used for preventing that oxygen from leaking by described electrolyte separator layer.
15. oxygen sensor as claimed in claim 14 is characterized in that, also comprises:
The first oxygen permeable/waterproof membrane (142), it is positioned at described venthole near an end of described electrolyte separator layer, to oxygen permeable, and is used for preventing that moisture content from entering described venthole;
Glass microfiber paper (144), it is used for helping to regulate the humidity of described electrolyte separator layer between described reservoir and described electrolyte separator layer; With
The second oxygen permeable/waterproof membrane (142), it is positioned at described blowhole near an end of described electrolyte separator layer, to oxygen permeable, and is used for preventing that moisture content from entering described blowhole.
16. oxygen sensor as claimed in claim 1, it is characterized in that, described electrolyte separator layer is a macromolecule membrane, and the material of described macromolecule membrane is selected from polypropylene, polyester, Nafion and GEFC, and described hydrophilic imbibition material is the glass fibre that infiltrated with described electrolytic solution.
17. a gas sensor, it comprises:
Electrolyte separator layer (110), it comprises at least one through hole (214,314,414), has been full of a kind of electrolytic solution in the described through hole;
At least one potential electrode (112), it is positioned at a side of described electrolyte separator layer, by a kind of reaction of gas in described potential electrode place generation reduction reaction and oxidation reaction of blowhole inflow;
At least one is to electrode (114), and it is positioned at the opposite side of described electrolyte separator layer, react at the described another kind that the electrode place is occured in reduction reaction and the oxidation reaction,
Wherein, the size of described at least one through hole and described blowhole is selected to and can prevents from being diffused into described potential electrode because of oxidation or reduction reaction the gas of described generation to the electrode place is reverse.
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| DE102009055416A1 (en) * | 2009-12-30 | 2011-07-07 | Robert Bosch GmbH, 70469 | Ceramic sensor element for small exhaust gas probes |
| CN102200525B (en) * | 2010-03-25 | 2014-02-26 | 华瑞科学仪器(上海)有限公司 | Chlorine dioxide measurement component and method, and gas sensor with component |
| CN102636542B (en) * | 2012-03-23 | 2014-02-26 | 华瑞科学仪器(上海)有限公司 | Gas sensor |
| GB2519110B (en) * | 2013-10-09 | 2018-04-18 | Nokia Technologies Oy | An apparatus and associated methods for analyte detection |
| JP6752558B2 (en) * | 2015-08-03 | 2020-09-09 | 新コスモス電機株式会社 | Constant potential electrolytic gas sensor |
| GB2604460B (en) * | 2017-11-01 | 2023-02-15 | Honeywell Int Inc | System and method for improved baseline stability of electrochemical sensor |
| US20200292486A1 (en) * | 2017-11-01 | 2020-09-17 | Honeywell International Inc. | System and method for improved baseline stability of electrochemical sensor |
| CN108680617B (en) * | 2018-03-26 | 2021-01-26 | 深圳市普晟传感技术有限公司 | Hydrogen sensor |
| CN111659917B (en) * | 2019-03-06 | 2023-04-14 | 复凌科技（上海）有限公司 | Method for detecting hole on module shell |
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| US5593558A (en) * | 1994-06-09 | 1997-01-14 | Nippondenso Co., Ltd. | Oxygen concentration detector |
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