Reference electrode and electrochemical sensor

Abstract

The embodiment of the utility model relates to the technical field of electrochemical sensors, in particular to a reference electrode and an electrochemical sensor. In the embodiment of the invention, the reference electrode comprises a liquid storage cavity, and the liquid storage cavity is used for accommodating a potassium chloride solution; a concentration indicating ball is further arranged in the liquid storage cavity and placed in the potassium chloride solution. When the concentration indicating ball floats on the liquid level of the potassium chloride solution, a user is prompted that the potassium chloride solution is in a saturated state, and the potassium chloride solution does not need to be replaced; when the concentration indicating ball sinks below the liquid level of the potassium chloride solution, a user is prompted that the potassium chloride solution is in an unsaturated state and needs to be replaced. Therefore, whether the concentration of the potassium chloride solution is changed from an initial saturated state to an unsaturated state can be judged by observing whether the concentration indicating ball floats on the liquid level of the potassium chloride solution, so that whether the potassium chloride solution in the liquid storage cavity needs to be replaced is judged.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of electrochemical sensors, and in particular, to a reference electrode and an electrochemical sensor. Background Art

[0002] In scientific research and engineering applications, the reference electrode is an important electrochemical tool and is widely used in electrochemical analysis, electrodeposition, electrosynthesis and electrolysis. The reference electrode is an electrode that forms a battery together with the working electrode. It acts as a transmission medium for current and is used to provide a stable potential reference so that the potential change of the working electrode can be accurately measured. It is usually made of inert materials such as platinum, gold and silver / silver chloride.

[0003] During the use of the silver / silver-silver chloride reference electrode, as the use time increases, the concentration of the potassium chloride solution in the reference electrode will gradually change from a saturated state to an unsaturated state, causing the potential of the reference electrode to become unstable, affecting the test accuracy of the working electrode potential. The change in the concentration of the potassium chloride solution in the reference electrode is not easy to detect, which is not conducive to timely replacement of the concentration of the potassium chloride solution. Utility Model Content

[0004] An embodiment of the present application provides a reference electrode, which is used for a solute potassium chloride solution and is also provided with a concentration indicator ball in a storage chamber. Whether the potassium chloride solution needs to be replaced can be determined by the relative position of the concentration indicator ball and the liquid surface of the potassium chloride solution.

[0005] In a first aspect of the present application, a reference electrode is provided, the reference electrode comprising: a shell, the shell having a detection hole, a liquid storage cavity arranged in the shell, the liquid storage cavity being connected to the external environment through the detection hole, the liquid storage cavity being used to accommodate a potassium chloride solution; a silver-silver chloride electrode, the silver-silver chloride electrode being mounted on the shell, one end of the silver-silver chloride electrode being used to be connected to an external circuit, the other end of the silver-silver chloride electrode being inserted into the liquid storage cavity and being used to contact the potassium chloride solution; a concentration indicating ball, the concentration indicating ball being arranged in the liquid storage cavity, if the concentration indicating ball floats on the liquid surface of the solution, it indicates that the potassium chloride solution is in a saturated state, if the concentration indicating ball sinks below the liquid surface, it indicates that the potassium chloride solution is in an unsaturated state; a semipermeable membrane, the semipermeable membrane being mounted in the liquid storage cavity, the semipermeable membrane being used to block a connection path between the liquid storage cavity and the detection hole, one side surface of the semipermeable membrane being used to contact the potassium chloride solution, and the other side surface of the semipermeable membrane being used to contact the liquid to be measured input from the detection hole.

[0006] In an embodiment of the present application, the reference electrode includes a liquid storage chamber, which is used to accommodate a potassium chloride solution; a concentration indicator ball is also provided in the liquid storage chamber, and the concentration indicator ball is placed in the potassium chloride solution. When the concentration indicator ball floats on the liquid surface of the potassium chloride solution, it prompts the user that the potassium chloride solution is in a saturated state and does not need to be replaced; when the concentration indicator ball sinks below the liquid surface of the potassium chloride solution, it prompts the user that the potassium chloride solution is in an unsaturated state and needs to be replaced. Therefore, by observing whether the concentration indicator ball floats on the liquid surface of the potassium chloride solution, it can be judged whether the concentration of the potassium chloride solution changes from an initial saturated state to an unsaturated state, thereby judging whether the potassium chloride solution in the liquid storage chamber needs to be replaced.

[0007] In some embodiments, the reference electrode further includes: a partition assembly, the partition assembly is disposed in the liquid storage cavity, the partition assembly separates the liquid storage cavity into a first liquid storage chamber and a second liquid storage chamber; wherein, the first liquid storage chamber is disposed on a side of the partition close to the silver-silver chloride electrode, one end of the silver-silver chloride electrode is inserted into the first liquid storage chamber, and the first liquid storage chamber is used to accommodate a potassium chloride solution; the second liquid storage chamber is disposed on a side of the partition away from the silver-silver chloride electrode, and the second liquid storage chamber is used to accommodate a potassium chloride solution and potassium chloride crystals immersed in the potassium chloride solution; the partition assembly is used to allow the potassium chloride solution to pass through and prevent the potassium chloride crystals from passing through.

[0008] In some embodiments, the partition assembly includes: a partition, the partition is provided with a partition mounting hole, the partition is used to separate the liquid storage cavity into a first liquid storage chamber and a second liquid storage chamber, the first liquid storage chamber is connected to the second liquid storage chamber through the partition mounting hole; a solid-liquid separation device, the solid-liquid separation device is installed in the partition mounting hole, the solid-liquid separator is used to allow the potassium chloride solution to pass through and prevent the potassium chloride crystals from passing through.

[0009] In some embodiments, the solid-liquid separator is a ceramic rod with a microporous structure, the ceramic rod is inserted into the partition mounting hole, and the microporous structure is used to allow the potassium chloride solution to pass through and prevent the potassium chloride crystals from passing through.

[0010] In some embodiments, the reference electrode further includes: a fixing component, the fixing component is disposed in the liquid storage cavity, the fixing component is used to fix the semipermeable membrane to the shell, and is used to seal the connection seam between the semipermeable membrane and the shell; the fixing component is provided with a fixing hole, the fixing hole extends through the fixing component, and the potassium chloride solution contacts the semipermeable membrane through the fixing hole.

[0011] In some embodiments, the fixing hole includes a first fixing hole and a second fixing hole connected to and matched with the first fixing hole; the fixing assembly includes: a pressure ring, the pressure ring having the first fixing hole, the first fixing hole extending through the pressure ring, the pressure ring being used to fix the semipermeable membrane to the shell; a buffer pad, the buffer pad is installed between the pressure ring and the semipermeable membrane, the buffer pad having the second fixing hole, and the second fixing hole extending through the buffer pad.

[0012] In some embodiments, the shell is further provided with a shell mounting through hole, and the liquid storage chamber is connected to the external environment through the shell mounting through hole; the reference electrode also includes: a metal contact, the metal contact is inserted into the shell mounting hole, and the metal contact is used to connect the silver-silver chloride electrode with an external circuit.

[0013] In some embodiments, the metal contacts are gold-plated metal contacts.

[0014] In some embodiments, the shell is further provided with a fluid exchange port, the fluid exchange port is communicated with the fluid storage chamber, and the fluid exchange port is used to introduce or discharge the potassium chloride solution into or out of the fluid storage chamber.

[0015] In a second aspect of the present application, an electrochemical sensor is further provided. The electrochemical sensor comprises a controller, an indicator electrode and the reference electrode described in the first aspect, wherein the controller is connected to the indicator electrode and the reference electrode.

[0016] It should be understood that the contents described in the summary of the invention are not intended to limit the key or important features of the present application, nor are they intended to limit the scope of the present application. Other features of the present application will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 is a schematic structural diagram of a reference electrode from one perspective provided in some embodiments of the present application;

[0019] Figure 2 is a schematic structural diagram of a reference electrode from one perspective provided in some embodiments of the present application;

[0020] Figure 3 It is a schematic diagram of the hardware structure of the electrochemical sensor provided in some embodiments of the present application. DETAILED DESCRIPTION

[0021] The principles and spirit of the present disclosure will be described below with reference to several exemplary embodiments shown in the accompanying drawings. It should be understood that the description of these specific embodiments is only to enable those skilled in the art to better understand and implement the present disclosure, and does not limit the scope of the present disclosure in any way. In the following description and claims, unless otherwise defined, all technical and scientific terms used herein have the meanings commonly understood by those of ordinary skill in the art.

[0022] As used herein, the term "including" and similar terms should be understood as open inclusion, i.e., "including but not limited to". The term "based on" should be understood as "based at least in part on". The term "one embodiment" or "the embodiment" should be understood as "at least one embodiment". The terms "first", "second", etc. may refer to different or the same objects, and are only used to distinguish the objects referred to, and do not imply a specific spatial order, temporal order, or order of importance of the objects referred to.

[0023] For example, Figure 1 The schematic diagram of the structure of the reference electrode provided in the embodiment of the present application is shown. Figure 1 As shown, the reference electrode 100 includes a housing 11, the housing 11 is provided with a detection hole 12, a liquid storage chamber 13 is provided in the housing 11, the liquid storage chamber 13 is communicated with the external environment through the detection hole 12, and the liquid storage chamber 13 is used to accommodate a potassium chloride solution; the reference electrode 100 also includes a silver-silver chloride electrode 14, a concentration indicator ball 15 and a semipermeable membrane 16. The potassium chloride solution is used to maintain the exchange current signal between the silver-silver chloride electrode 14 and the liquid sample, maintain the stability of the potassium chloride solution concentration, and is conducive to improving the stability and reaction rate of the reference electrode 100.

[0024] In some embodiments, the silver-silver chloride electrode 14 is mounted on the housing 11, one end of the silver-silver chloride electrode 14 is used to connect to an external circuit, and the other end of the silver-silver chloride electrode 14 is inserted into the liquid storage chamber 13 and is used to contact the potassium chloride solution in the liquid storage chamber 13. The silver-silver chloride electrode 14 includes a silver rod and a silver chloride layer coated on the surface of the silver chloride.

[0025] In some embodiments, the concentration indicator ball 15 is disposed in the liquid storage chamber 13 to indicate whether the concentration of the potassium chloride solution in the liquid storage chamber 13 changes from a saturated state to an unsaturated state. Under normal circumstances, the potassium chloride solution in the liquid storage chamber 13 is in a saturated state; at this time, the potential of the reference electrode 100 is stable, and the test accuracy of the working electrode potential is high. The density of the concentration indicator ball 15 can be slightly lower than the density of the saturated potassium chloride solution. When the concentration indicator ball 15 floats on the surface of the potassium chloride solution, it prompts the user that the potassium chloride solution is in a saturated state and does not need to be replaced; when the concentration indicator ball 15 sinks below the surface of the potassium chloride solution, it prompts the user that the potassium chloride solution is in an unsaturated state and needs to be replaced.

[0026] In some embodiments, a semipermeable membrane 16 is installed in the liquid storage chamber 13, and the semipermeable membrane 16 is used to block the connection path between the liquid storage chamber 13 and the detection hole 12, and one side surface of the semipermeable membrane 16 is used to contact with the potassium chloride solution, and the other side surface of the semipermeable membrane 16 is used to contact with the liquid to be tested (that is, the liquid sample) input from the detection hole 12. The semipermeable membrane 16 has a suitable molecular weight cutoff, which can control the precipitation rate of the inner filling liquid to the greatest extent without affecting the potential exchange between the inner filling liquid (that is, the potassium chloride solution) and the liquid sample, and prolong the saturation time of the inner filling liquid.

[0027] In an embodiment of the present application, the reference electrode 100 includes a liquid storage chamber 13, which is used to accommodate a potassium chloride solution; a concentration indicator ball 15 is also provided in the liquid storage chamber 13, and the concentration indicator ball 15 is placed in the potassium chloride solution. When the concentration indicator ball 15 floats on the liquid surface of the potassium chloride solution, the potassium chloride solution is in a saturated state, and when the potassium chloride solution is in an unsaturated state, the concentration indicator ball 15 sinks below the liquid surface of the potassium chloride solution. Therefore, by observing whether the concentration indicator ball 15 floats on the liquid surface of the potassium chloride solution, it can be determined whether the concentration of the potassium chloride solution changes from an initial saturated state to an unsaturated state, thereby determining whether the potassium chloride solution in the liquid storage chamber 13 needs to be replaced.

[0028] In some embodiments, the reference electrode 100 further includes: a partition assembly 17, wherein the partition assembly 17 is disposed in the liquid storage chamber 13, and the partition assembly 17 separates the liquid storage chamber 13 into a first liquid storage chamber 131 and a second liquid storage chamber 132; wherein the first liquid storage chamber 131 is disposed on a side of the partition close to the silver-silver chloride electrode 14, one end of the silver-silver chloride electrode 14 is inserted into the first liquid storage chamber 131, and the first liquid storage chamber 131 is used to accommodate a potassium chloride solution; the second liquid storage chamber 132 is disposed on a side of the partition away from the silver-silver chloride electrode 14, and the second liquid storage chamber 132 is used to accommodate a potassium chloride solution and potassium chloride crystals immersed in the potassium chloride solution; the partition assembly 17 is used to allow the potassium chloride solution to pass through and prevent the potassium chloride crystals from passing through. In this embodiment, since the second liquid storage chamber 132 is also provided with potassium chloride crystals immersed in potassium chloride solution, and the potassium chloride solution in the second liquid storage chamber 132 can enter the first liquid storage chamber 131 through the partition assembly 17, when the concentration of the potassium chloride solution in the first liquid storage chamber 131 and / or the second liquid storage chamber 132 is lower than the saturation of potassium chloride, the potassium chloride crystals will automatically dissolve, which is conducive to maintaining the concentration of the potassium chloride solution in the first liquid storage chamber 131 and the second liquid storage chamber 132 at a saturated state for a long time, thereby improving the stability of the reference electrode 100 and extending the service life of the reference electrode 100. Since the potassium chloride crystals in the second liquid storage chamber 132 are solid, the potassium chloride crystals in the second liquid storage chamber 132 cannot enter the first liquid storage chamber 131 through the partition assembly 17. It is prevented that the potassium chloride crystals in the second liquid storage chamber 132 enter the first liquid storage chamber 131 and contact with the silver-silver chloride electrode 14 of the first liquid storage chamber 131, causing an adverse effect on the silver-silver chloride electrode 14, thereby further improving the stability of the reference electrode 100.

[0029] In some embodiments, the partition assembly 17 includes: a partition 171 and a solid-liquid separator 172 installed on the partition 171, wherein the partition 171 is provided with a partition installation through hole, the first liquid storage chamber 131 is connected with the second liquid storage chamber 132 through the partition installation through hole, and the solid-liquid separator 172 is installed in the partition installation through hole. The partition 171 is used to separate the liquid storage cavity 13 into the first liquid storage chamber 131 and the second liquid storage chamber 132; the solid-liquid separator 172 is used to allow the potassium chloride solution to pass through and prevent the potassium chloride crystals from passing through.

[0030] Specifically, in some embodiments, the solid-liquid separator 172 is a ceramic rod with a microporous structure, the ceramic rod is inserted into the partition mounting through hole, and the microporous structure is used to allow the potassium chloride solution to pass through and prevent the potassium chloride crystals from passing through. In this embodiment, the potassium chloride solution in the second liquid storage chamber 132 and the first liquid storage chamber 131 can be exchanged through the micropores of the ceramic rod, and the potassium chloride crystals in the second liquid storage chamber 132 cannot enter the first liquid storage chamber 131 through the microporous structure of the ceramic rod.

[0031] In some embodiments, the reference electrode 100 further includes a fixing component 18, which is disposed in the liquid storage chamber 13, and is used to fix the semipermeable membrane 16 to the shell 11, and to seal the connection seam between the semipermeable membrane 16 and the shell 11; the fixing component 18 is provided with a fixing hole, which extends through the fixing component 18, and the potassium chloride solution contacts the semipermeable membrane 16 through the fixing hole.

[0032] In some embodiments, the fixing hole includes a first fixing hole 1811 and a second fixing hole 1821 connected to and matched with the first fixing hole 1811; the fixing assembly 18 includes: a pressure ring, the pressure ring has a first fixing hole 1811, the first fixing hole 1811 extends through the pressure ring 181, and the pressure ring is used to fix the semipermeable membrane 16 to the shell 11; a buffer pad 182, the buffer pad is installed between the pressure ring and the semipermeable membrane 16, the buffer pad has a second fixing hole 1821, and the second fixing hole 1821 extends through the buffer pad.

[0033] In some embodiments, the shell 11 is also provided with a shell mounting through hole 19, and the liquid storage chamber 13 is connected to the external environment through the shell mounting through hole 19; the reference electrode 100 also includes: a metal contact 20, the metal contact 20 is inserted into the shell mounting through hole 19, and the metal contact 20 is used to connect the silver-silver chloride electrode 14 with an external circuit. In some embodiments, the metal contact is a gold-plated metal contact. The corrosion resistance of the gold-plated layer is higher than that of Ag, so that the metal contact 20 is not prone to the phenomenon of unstable electrical signal transmission due to oxidation. Specifically, the gold-plated metal contact includes a copper substrate and a gold-plated layer disposed on the copper substrate. Specifically, in some embodiments, one end of the silver-silver chloride electrode 14 is welded to the metal contact 20, and the other end of the silver-silver chloride electrode 14 is inserted into the liquid storage chamber 13.

[0034] In some embodiments, the housing 11 is further provided with a liquid exchange port 21, the liquid exchange port 21 is in communication with the liquid storage chamber 13, and the liquid exchange port 21 is used to introduce or discharge the potassium chloride solution into or out of the liquid storage chamber 13. In other embodiments, the reference electrode 100 is further provided with a cover body used in conjunction with the liquid exchange port 21, and the opening and closing of the liquid exchange port 21 is controlled by the cover body.

[0035] In a second aspect of the present application, an electrochemical sensor, such as an electrolyte analyzer, is also provided. Exemplarily, Figure 3 The hardware structure of the electrochemical sensor is shown. Figure 3As shown, the electrochemical sensor 300 includes a controller 310, an indicator electrode 320 and a reference electrode 330 provided in the above embodiment, and the controller 310 is connected to the indicator electrode 320 and the reference electrode 330. In the embodiment of the present application, the electrode whose potential value changes with the change of the activity (concentration) of the measured ion is called the indicator electrode. The electrode whose potential value is known and constant is called the reference electrode; that is, the potential value of the reference electrode is not affected by the activity (concentration) of the measured ion in the solution.

[0036] In the embodiments of the present application, the service life of the reference electrode is increased, which can reduce the instrument maintenance cost of the customer. Moreover, the internal filling liquid of the reference electrode is always in a saturated state, the stability of the reference electrode is guaranteed, and the test accuracy of the electrolyte analyzer is also improved.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. Under the concept of the present invention, the technical features in the above embodiments or different embodiments may also be combined, the steps may be implemented in any order, and there are many other changes in different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they may still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A reference electrode, characterized in that The reference electrode comprises: A shell, wherein the shell is provided with a detection hole, a liquid storage cavity is provided in the shell, the liquid storage cavity is communicated with the external environment through the detection hole, and the liquid storage cavity is used to contain a potassium chloride solution; A silver-silver chloride electrode, wherein the silver-silver chloride electrode is mounted on the housing, one end of the silver-silver chloride electrode is used to be connected to an external circuit, and the other end of the silver-silver chloride electrode is inserted into the liquid storage cavity and is used to contact the potassium chloride solution; A concentration indicator ball, wherein the concentration indicator ball is disposed in the liquid storage cavity. If the concentration indicator ball floats on the liquid surface of the solution, it indicates that the potassium chloride solution is in a saturated state; if the concentration indicator ball sinks below the liquid surface, it indicates that the potassium chloride solution is in an unsaturated state; A semipermeable membrane is installed in the liquid storage cavity, the semipermeable membrane is used to block the connection path between the liquid storage cavity and the detection hole, one side surface of the semipermeable membrane is used to contact with the potassium chloride solution, and the other side surface of the semipermeable membrane is used to contact with the liquid to be tested input from the detection hole.

2. The reference electrode according to claim 1, characterized in that The reference electrode also includes: A partition assembly, wherein the partition assembly is disposed in the liquid storage cavity, and the partition assembly separates the liquid storage cavity into a first liquid storage chamber and a second liquid storage chamber; Wherein, the first liquid storage chamber is arranged on a side of the partition close to the silver-silver chloride electrode, one end of the silver-silver chloride electrode is inserted into the first liquid storage chamber, and the first liquid storage chamber is used to contain potassium chloride solution; The second liquid storage chamber is arranged on a side of the partition away from the silver-silver chloride electrode, and the second liquid storage chamber is used to accommodate potassium chloride solution and potassium chloride crystals immersed in the potassium chloride solution; The partition assembly is used for allowing the potassium chloride solution to pass through and preventing the potassium chloride crystals from passing through.

3. The reference electrode according to claim 2, characterized in that The partition assembly comprises: A partition, wherein the partition is provided with a partition installation through hole, and the partition is used to separate the liquid storage cavity into a first liquid storage chamber and a second liquid storage chamber, and the first liquid storage chamber is connected with the second liquid storage chamber through the partition installation through hole; A solid-liquid separation device is installed in the partition installation through hole, and the solid-liquid separator is used to allow the potassium chloride solution to pass through and prevent the potassium chloride crystals from passing through.

4. The reference electrode according to claim 3, characterized in that The solid-liquid separator is a ceramic rod with a microporous structure, the ceramic rod is inserted into the partition mounting through hole, and the microporous structure is used to allow the potassium chloride solution to pass through and prevent the potassium chloride crystals from passing through.

5. The reference electrode according to any one of claims 1 to 4, characterized in that The reference electrode also includes: A fixing assembly, the fixing assembly is disposed in the liquid storage cavity, the fixing assembly is used to fix the semipermeable membrane to the shell, and is used to seal the connection seam between the semipermeable membrane and the shell; The fixing component is provided with a fixing hole, and the fixing hole extends through the fixing component. The potassium chloride solution contacts the semipermeable membrane through the fixing hole.

6. The reference electrode according to claim 5, characterized in that The fixing hole comprises a first fixing hole and a second fixing hole connected to and matching the first fixing hole; The fixing assembly comprises: A pressing ring, wherein the pressing ring is provided with the first fixing hole, the first fixing hole extends through the pressing ring, and the pressing ring is used to fix the semipermeable membrane to the housing; A buffer pad is installed between the pressure ring and the semipermeable membrane, and the buffer pad is provided with the second fixing hole, and the second fixing hole extends through the buffer pad.

7. The reference electrode according to any one of claims 1 to 4, characterized in that The shell is also provided with a shell installation through hole, and the liquid storage cavity is connected with the external environment through the shell installation through hole; The reference electrode also includes: A metal contact is inserted into the housing mounting hole, and the metal contact is used to connect the silver-silver chloride electrode with an external circuit.

8. The reference electrode according to claim 7, characterized in that The metal contacts are gold-plated metal contacts.

9. The reference electrode according to any one of claims 1 to 4, characterized in that: The shell is also provided with a liquid replacement port, which is communicated with the liquid storage cavity and is used to introduce or discharge the potassium chloride solution into or out of the liquid storage cavity.

10. An electrochemical sensor, characterized in that: The electrochemical sensor comprises a controller, an indicator electrode and a reference electrode according to any one of claims 1 to 9, wherein the controller is connected to the indicator electrode and the reference electrode.

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