CN213275435U - Dissolved oxygen sensor and system thereof - Google Patents
Dissolved oxygen sensor and system thereof Download PDFInfo
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- CN213275435U CN213275435U CN202022262233.2U CN202022262233U CN213275435U CN 213275435 U CN213275435 U CN 213275435U CN 202022262233 U CN202022262233 U CN 202022262233U CN 213275435 U CN213275435 U CN 213275435U
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Abstract
The present application relates to a dissolved oxygen sensor and a system thereof. Wherein, dissolved oxygen sensor includes: the sensor comprises an electrolyte cavity, a sensor nut and a membrane cover, wherein the sensor nut is detachably arranged at one end of the electrolyte cavity; a cathode used as a working electrode and an anode used as an auxiliary electrode are also arranged in the electrolyte cavity, and leads respectively connected with the working electrode and the auxiliary electrode penetrate out of the sensor nut; the membrane cover comprises a through hole, and an oxygen permeation membrane is arranged between the membrane cover and the electrolyte cavity. The dissolved oxygen sensor that so sets up and obtains is rational in infrastructure to can improve detection accuracy and sensitivity, in addition, in the system including above-mentioned dissolved oxygen sensor, still include wireless communication module, thereby can realize data teletransmission through wireless communication module, and then can show the detection data in inconvenient on-the-spot long-range demonstration when showing the detection data, convenience of customers looks over.
Description
Technical Field
The application relates to the technical field of dissolved oxygen detection, in particular to a dissolved oxygen sensor and a system thereof.
Background
The molecular oxygen dissolved in water is called Dissolved Oxygen (DO), and is one of the important indicators for water quality monitoring. The trace dissolved oxygen is an important detection index for energy power and nuclear industry water supplement, and the trace dissolved oxygen sensing technology is mainly applied to related industries such as thermal power plants, nuclear power plants and the like. In industrial production, the dissolved oxygen in boiler feed water and condensate has high activity, is easy to react with a boiler device made of metal materials to cause uneven stress, and can cause boiler explosion under serious conditions, so that the method has very important significance in accurately, rapidly and accurately monitoring the dissolved oxygen in boiler water. In addition, oxygen content is also an important monitoring index in the manufacturing process of beer, beverages and biological agents. Based on this, dissolved oxygen sensors are commonly used in the related art to monitor the oxygen content in water.
The existing film-covered sensor has low detection precision and poor sensitivity due to unreasonable factors (electrode materials and sensor structures) such as the structure, so that the measurement requirement under a special scene cannot be met. In addition, after the dissolved oxygen is detected, the detected value needs to be displayed in real time so as to be checked, but in many cases, the field working condition is inconvenient to display.
SUMMERY OF THE UTILITY MODEL
The application provides a dissolved oxygen sensor and system thereof to solve the problems of low detection precision, poor sensitivity and inconvenient field display of the existing film-coated sensor due to unreasonable structure.
The above object of the present application is achieved by the following technical solutions:
in a first aspect, the present application provides a dissolved oxygen sensor comprising: the sensor comprises an electrolyte cavity, a sensor nut and a membrane cover, wherein the sensor nut is detachably arranged at one end of the electrolyte cavity;
a cathode used as a working electrode and an anode used as an auxiliary electrode are also arranged in the electrolyte cavity, and leads respectively connected with the working electrode and the auxiliary electrode penetrate out of the sensor nut;
the membrane cover comprises a through hole, and an oxygen permeable membrane is arranged between the membrane cover and the electrolyte cavity; the sensor screw cap, the electrolyte cavity, the oxygen permeation membrane and the membrane cover form a sealed cavity for storing electrolyte.
Optionally, the sensor nut is further connected with an electrode base extending into the electrolyte cavity;
the working electrode is embedded in one end of the electrode base, which is not connected with the sensor nut, and comprises a surface which is in contact with the oxygen permeation membrane;
the auxiliary electrode is of a double-spiral structure sleeved on the electrode base.
Optionally, the working electrode is made of gold, and the auxiliary electrode is made of silver; the ratio of the surface area of the auxiliary electrode to the working electrode is between 28-35.
Optionally, the surface of the working electrode in contact with the oxygen permeable membrane is a convex arc surface.
Optionally, the oxygen permeable membrane is made of a perfluorinated ethylene propylene copolymer material with the thickness of 10-50 microns.
Optionally, the sensor nut and the electrolyte cavity and the membrane cover and the electrolyte cavity are detachably connected through inner and outer threads.
Optionally, the side surface of the electrolyte cavity is provided with an air hole through a screw cap.
Optionally, the nut outer ring is further provided with a layer of rubber ring.
Optionally, the sensor nut, the electrolyte cavity, the membrane cover and the electrode base are all made of polytetrafluoroethylene materials.
In a second aspect, embodiments of the present application further provide a dissolved oxygen sensor system, which includes: temperature sensor, first aspect any dissolved oxygen sensor, with temperature sensor with the data acquisition module that dissolved oxygen sensor is connected, with the wireless communication module that the data acquisition module is connected and with the host computer that wireless communication module is connected.
The technical scheme provided by the embodiment of the application can have the following beneficial effects:
in the technical scheme that the embodiment of this application provided, dissolved oxygen sensor includes the electrolyte cavity, can dismantle sensor nut and the membrane lid of being connected with the electrolyte cavity, and the inside negative pole that still is provided with as working electrode of electrolyte cavity and the positive pole as auxiliary electrode, and the membrane is covered including the through-hole, is provided with the oxygen permeation membrane between membrane lid and the electrolyte cavity to sensor nut, electrolyte cavity, oxygen permeation membrane and membrane lid form the seal chamber who stores electrolyte. The dissolved oxygen sensor that so sets up and obtains is rational in infrastructure to can improve detection accuracy and sensitivity, in addition, in the system including above-mentioned dissolved oxygen sensor, still include wireless communication module, thereby can realize data teletransmission through wireless communication module, and then can show the detection data in inconvenient on-the-spot long-range demonstration when showing the detection data, convenience of customers looks over.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and together with the description, serve to explain the principles of the application.
Fig. 1 is a schematic structural diagram of a dissolved oxygen sensor according to an embodiment of the present disclosure, which includes an exploded view (left) and a front view (right).
FIG. 2 is a schematic diagram illustrating operation of a dissolved oxygen sensor system according to an embodiment of the present disclosure;
fig. 3 is a schematic circuit connection diagram of a dissolved oxygen sensor system according to an embodiment of the present disclosure.
Detailed Description
Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.
Examples
Referring to fig. 1, fig. 1 is a schematic structural diagram of a dissolved oxygen sensor according to an embodiment of the present disclosure, which includes an exploded view (left) and a front view (right).
As shown in fig. 1, the dissolved oxygen sensor mainly includes: the sensor comprises an electrolyte cavity 11 with a cylindrical structure, a sensor nut 12 detachably arranged at one end of the electrolyte cavity 11 and a membrane cover 13 detachably arranged at the other end of the electrolyte cavity 11;
a cathode used as a working electrode 14 and an anode used as an auxiliary electrode 15 are also arranged in the electrolyte cavity 11, and leads respectively connected with the working electrode 14 and the auxiliary electrode 15 penetrate out of the sensor nut 12;
the membrane cover 13 comprises a through hole, and an oxygen permeable membrane 16 is arranged between the membrane cover 13 and the electrolyte cavity 11, namely, when the dissolved oxygen sensor is placed in a solution to be detected for detection, the dissolved oxygen in the solution to be detected can penetrate through the oxygen permeable membrane 16 from the through hole of the membrane cover 13 and enter the electrolyte cavity 11; and the sensor screw cap 12, the electrolyte chamber 11, the oxygen permeable membrane 16 and the membrane cover 13 form a sealed chamber for storing electrolyte.
Wherein, the detachable connection mode between sensor nut 12 and electrolyte cavity 11 and between membrane lid 13 and electrolyte cavity 11 all can be through interior external screw thread fit connection, for example, according to the structure shown in fig. 1 (left): the sensor screw cap 12 comprises an external thread, one end of the electrolyte cavity 11 matched with the sensor screw cap comprises an internal thread, the membrane cover 13 comprises an internal thread, one end of the electrolyte cavity 11 matched with the electrolyte cavity comprises an external thread, and the oxygen permeable membrane 16 is tightly pressed between the membrane cover 13 and the electrolyte cavity 11; the threaded connection can provide good sealing of the entire chamber.
In addition, as a possible embodiment, the working electrode 14 and the auxiliary electrode 15 are arranged as shown in fig. 1 (left), and the sensor nut 12 is further connected with an electrode base 17 extending into the electrolyte chamber 11. The working electrode 14 with one end of a cap-shaped cylinder structure is embedded in one end of the electrode base 17, which is not connected with the sensor nut 12 (the structure shown in fig. 1 is that the working electrode 14 is embedded in the lower end of the electrode base 17), and the working electrode 14 includes a surface in contact with the oxygen permeable membrane 16 (in fig. 1, after the sensor nut 12 is arranged on the electrolyte cavity 11, the lower end surface of the working electrode 14 is in contact with the oxygen permeable membrane 16, that is, the cap-shaped structure surface is in contact with the oxygen permeable membrane 16), and in some embodiments, the surface in contact with the oxygen permeable membrane 16 of the working electrode 14 is a convex arc surface (that is, the cap-shaped structure surface is a convex arc surface), so that the contact area with the oxygen permeable membrane 16 can be increased. The auxiliary electrode 15 is a double-spiral structure (similar to a spring structure) sleeved on the electrode base 17, and one end of the auxiliary electrode 15 is fixed on the sensor nut 12. Furthermore, the line of the working electrode 14 runs through the electrode base 17 to the sensor nut 12, while the line of the auxiliary electrode 15 runs directly out of the sensor nut 12.
Further, the working electrode 14 is made of gold, and the auxiliary electrode 15 is made of silver; the ratio of the surface area of the auxiliary electrode 15 to the working electrode 14 is between 28-35. That is, the ratio of the surface area of the auxiliary electrode 15 in contact with the electrolyte to the surface area of the working electrode 14 in contact with the oxygen permeable membrane 16 is between 28 and 35, thereby ensuring good measurement accuracy and response speed.
Accordingly, one possible method of preparing the working electrode 14 (gold cathode) and the auxiliary electrode 15 (silver anode) is as follows:
method for preparing working electrode 14: welding a lead on the bottom of the cylindrical gold electrode by using low-temperature soldering tin, uniformly coating a layer of epoxy resin glue on the side surface of the electrode, embedding the gold electrode into a matched electrode base 17 made of polytetrafluoroethylene, and curing for 12 hours at room temperature. And (3) polishing the front end of the cylindrical electrode to form an arc surface by using alumina sand paper, and cleaning by using deionized water. The circular arc surface was polished with sandpaper and ultrasonically cleaned with deionized water. Finally, removing the metal oxide on the surface by using hot dilute nitric acid, and removing organic matters on the surface by using absolute ethyl alcohol.
The preparation method of the auxiliary electrode 15 comprises the following steps: cutting a plurality of high-purity silver wires with the diameter of 1mm, carrying out ultrasonic cleaning by using deionized water, carrying out annealing treatment for 30 minutes, polishing by using sand paper to remove oxides on the surface, carrying out ultrasonic cleaning by using deionized water, and winding the silver wires into a double-spiral spring shape by using a winding machine.
In addition, the electrolyte is a mixed solution of potassium chloride (KCL) and potassium hydroxide (KOH), wherein the electrolyte comprises the following components in percentage by weight: 74.55 parts of potassium chloride, 0.561 part of potassium hydroxide and 1000 parts of water.
Further, the oxygen permeable membrane 16 may be made of a 10-50 μm thick Fluorinated Ethylene Propylene (FEP) material, with 30 μm being preferred to ensure optimal sensor performance. In addition, the main body of the whole cavity, namely the sensor nut 12, the electrolyte cavity 11, the membrane cover 13 and the electrode base 17 can be made of Polytetrafluoroethylene (PTFE) materials, and the materials have the advantages of chemical corrosion resistance, good insulating property, easiness in processing, difficulty in aging and the like.
In addition, in some embodiments, as shown in fig. 1, the side surface of the electrolyte chamber 11 is further provided with an air hole through the screw cap 18, so that after the screw cap 18 is screwed out, redundant gas inside the chamber can be released through the air hole, and after the redundant gas is released, the sealing performance of the whole chamber can be ensured only by screwing the screw cap 18. Further, a rubber ring (not shown) may be disposed around the screw cap 18 to further prevent the electrolyte inside the chamber from leaking.
The working principle of the dissolved oxygen sensor is as follows:
based on Clark tectorial membrane electrode method, working electrode is made by high-purity gold, and auxiliary electrode is made by silver silk, is full of the mixed solution of KCL and KOH in the electrolyte cavity as the electrolyte, and the top of sensor covers a layer of selective oxygen permeation membrane, and when the polarization voltage of 0.68V is added between working electrode and the auxiliary electrode, the dissolved oxygen of the solution to be measured can pass through the selective oxygen permeation membrane, diffuse to the electrolyte, and be reduced on working electrode, produce a stable diffusion current between working electrode and the auxiliary electrode simultaneously. The magnitude of the diffusion current is proportional to the oxygen concentration at the surface of the working electrode. The concentration of dissolved oxygen in the solution to be detected can be measured by detecting the magnitude of the diffusion current. Wherein, the chemical equation of the electrode surface reaction process is as follows:
a working electrode: o is2+2H2O+4e-→4OH-
Auxiliary electrode: 4Ag +4Cl-→4AgCl+4e-
And (3) total reaction: o is2+2H2O+4Ag+4Cl-→4AgCl+4OH-
In addition, on the basis of above-mentioned scheme, this application still provides a dissolved oxygen sensor system, can carry out remote data processing and demonstration with the detected value teletransmission of dissolved oxygen sensor to the host computer through this system.
Referring to fig. 2, fig. 2 is a schematic diagram illustrating operation of a dissolved oxygen sensor system according to an embodiment of the present disclosure;
as shown in fig. 2, the system includes a temperature sensor 2, a dissolved oxygen sensor 1 according to the foregoing embodiment, a data acquisition module 3 connected to the temperature sensor 2 and the dissolved oxygen sensor 1, a wireless communication module 4 connected to the data acquisition module 3, and an upper computer 5 connected to the wireless communication module 4.
During specific application, dissolved oxygen sensor 1's one end (membrane lid end) stretches into in the inside solution 7 that awaits measuring of sealed flow-through cell 6 to for convenient fixing dissolved oxygen sensor 1, can set up the fixture block (for example the outside ring shape structure of the electrolyte cavity shown in fig. 1) in the outside of electrolyte cavity 11, thereby avoid dissolved oxygen sensor 1 whole to get into in the sealed flow-through cell 6 through the fixture block. Two wires that dissolved oxygen sensor 1 draws are connected with data acquisition module 3, simultaneously temperature sensor 2 wholly immerses in solution 7 that awaits measuring, and be connected with data acquisition module 3 through the wire, thereby data acquisition module 3 can acquire the diffusion current of the inside formation of dissolved oxygen sensor 1, and obtain the content data of dissolved oxygen after carrying out a series of processing to it, and obtain the temperature signal that temperature sensor 2 gathered and obtain the temperature data of the solution that awaits measuring, then pass through wireless sending module with relevant data far to wireless receiving module (wireless sending module and wireless receiving module constitute wireless communication module 4), upload data to host computer 5 through USB serial ports or similar form by wireless receiving module again and carry out data processing and demonstration.
It should be noted that the dissolved oxygen detection is related to the temperature of the solution to be measured, and the temperature needs to be compensated. Based on this, the accuracy of the detected dissolved oxygen data can be ensured by detecting the temperature of the solution to be detected.
More specifically, the circuit structure of the dissolved oxygen sensor system provided in the present application is described with reference to fig. 3, where fig. 3 is a schematic circuit connection diagram of a dissolved oxygen sensor system according to an embodiment of the present application. As shown in fig. 3, the system mainly includes:
a dissolved oxygen detection probe and a temperature sensor which are arranged in the measured solution flow cell; wherein, the temperature sensor adopts a stainless steel waterproof digital temperature sensor, such as a digital temperature sensor with the model number of DS18B 20;
the power supply circuit is used for supplying power to each power utilization circuit;
a polarization voltage circuit and a voltage follower connected thereto for providing a polarization voltage (0.68V) applied between the working electrode and the auxiliary electrode;
the current-voltage conversion circuit is used for converting the obtained diffusion current signal of the dissolved oxygen sensor into a voltage signal;
the amplifying circuit and the filter circuit connected with the amplifying circuit are used for amplifying and filtering the voltage signal;
the microprocessor can adopt an ADuC847 processor with high-precision AD conversion (analog-to-digital conversion) for AD conversion of the amplified and filtered voltage signals; the circuit structure of the power supply circuit, the polarization voltage circuit (including a voltage follower), the current-voltage conversion circuit, the amplifying circuit, the filter circuit, the microprocessor (including an AD conversion circuit) and the like is a component of the data acquisition module, and can be integrated on a circuit board during specific implementation;
the wireless transceiver unit, namely the communication module, comprises a wireless transmitting unit connected with the (microprocessor of the) data acquisition module and a wireless receiving unit connected with the upper computer; in specific implementation, a LoRa long-distance radio transmission scheme can be adopted, so that high-speed long-distance wireless transmission is realized under low power consumption;
and the upper computer is used for processing and displaying the received data so as to be convenient for a user to view.
It should be noted that, the data acquisition module has been widely used in the related schemes in the prior art, so the specific structure of the related circuit directly adopts the scheme in the prior art, and the details are not described here.
Through the scheme, firstly, the dissolved oxygen sensor comprises the electrolyte cavity, the sensor nut and the membrane cover which are detachably connected with the electrolyte cavity, the cathode as the working electrode and the anode as the auxiliary electrode are also arranged inside the electrolyte cavity, the membrane cover comprises the through hole, and the oxygen permeation membrane is arranged between the membrane cover and the electrolyte cavity, so that the sensor nut, the electrolyte cavity, the oxygen permeation membrane and the membrane cover form a sealed cavity for storing electrolyte. The dissolved oxygen sensor obtained by the arrangement has a reasonable structure, so that the detection precision and sensitivity can be improved. In addition, among the system including above-mentioned dissolved oxygen sensor, still include wireless communication module to can realize data teletransmission through wireless communication module, and then can be at inconvenient on-the-spot long-range demonstration detected data when showing detected data, convenience of customers looks over
It is understood that the same or similar parts in the above embodiments may be mutually referred to, and the same or similar parts in other embodiments may be referred to for the content which is not described in detail in some embodiments.
In the description herein, reference to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the application. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
Although embodiments of the present application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present application, and that variations, modifications, substitutions and alterations may be made to the above embodiments by those of ordinary skill in the art within the scope of the present application.
Claims (10)
1. A dissolved oxygen sensor, comprising: the sensor comprises an electrolyte cavity, a sensor nut and a membrane cover, wherein the sensor nut is detachably arranged at one end of the electrolyte cavity;
a cathode used as a working electrode and an anode used as an auxiliary electrode are also arranged in the electrolyte cavity, and leads respectively connected with the working electrode and the auxiliary electrode penetrate out of the sensor nut;
the membrane cover comprises a through hole, and an oxygen permeable membrane is arranged between the membrane cover and the electrolyte cavity; the sensor screw cap, the electrolyte cavity, the oxygen permeation membrane and the membrane cover form a sealed cavity for storing electrolyte.
2. The dissolved oxygen sensor of claim 1, wherein the sensor nut is further coupled with an electrode base that extends into the electrolyte chamber;
the working electrode is embedded in one end of the electrode base, which is not connected with the sensor nut, and comprises a surface which is in contact with the oxygen permeation membrane;
the auxiliary electrode is of a double-spiral structure sleeved on the electrode base.
3. The dissolved oxygen sensor according to claim 2, wherein the material of the working electrode is gold, and the material of the auxiliary electrode is silver; the ratio of the surface area of the auxiliary electrode to the working electrode is between 28-35.
4. The dissolved oxygen sensor according to claim 2 or 3, wherein the surface of the working electrode in contact with the oxygen permeable membrane is a convex arc surface.
5. The dissolved oxygen sensor of claim 1, wherein the oxygen permeable membrane is made of a 10-50 μm thick perfluoroethylene propylene material.
6. The dissolved oxygen sensor of claim 1, wherein the sensor nut and the electrolyte chamber and the membrane cover and the electrolyte chamber are detachably connected by internal and external threads.
7. The dissolved oxygen sensor of claim 1, wherein the side of the electrolyte chamber is further provided with air holes by screw caps.
8. The dissolved oxygen sensor of claim 7, wherein the screw cap outer ring is further provided with a layer of rubber ring.
9. The dissolved oxygen sensor of claim 2, wherein the sensor nut, the electrolyte chamber, the membrane cover, and the electrode base are all made of polytetrafluoroethylene material.
10. A dissolved oxygen sensor system, comprising: the system comprises a temperature sensor, the dissolved oxygen sensor as claimed in any one of claims 1 to 9, a data acquisition module connected with the temperature sensor and the dissolved oxygen sensor, a wireless communication module connected with the data acquisition module, and an upper computer connected with the communication module.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
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| CN202022262233.2U CN213275435U (en) | 2020-10-12 | 2020-10-12 | Dissolved oxygen sensor and system thereof |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202022262233.2U CN213275435U (en) | 2020-10-12 | 2020-10-12 | Dissolved oxygen sensor and system thereof |
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| CN213275435U true CN213275435U (en) | 2021-05-25 |
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| CN202022262233.2U Active CN213275435U (en) | 2020-10-12 | 2020-10-12 | Dissolved oxygen sensor and system thereof |
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