CN214201273U

CN214201273U - Reference electrode potential measuring and calculating device of miniature electrochemical sensor

Info

Publication number: CN214201273U
Application number: CN202023166484.7U
Authority: CN
Inventors: 陆世龙; 黄欣; 吴江
Original assignee: Jiangsu Yingnuomide Technology Co ltd
Current assignee: Jiangsu Yingnuomide Technology Co ltd
Priority date: 2020-12-24
Filing date: 2020-12-24
Publication date: 2021-09-14
Anticipated expiration: 2030-12-24

Abstract

The utility model discloses a miniature electrochemical sensor reference electrode potential measuring device, including airtight casing, reference electrode, temperature sensor, conductivity sensor, measuring circuit and working electrode, be provided with reference electrode, temperature sensor and conductivity sensor in the airtight casing, reference electrode, temperature sensor, conductivity sensor and working electrode all are connected with the measuring circuit electricity through the connecting wire. The utility model belongs to the technical field of the sensor, the utility model aims to solve among the prior art electrochemical sensor stability of reference potential when measuring not high, there is potential drift, and life is limited to the problem of direct measurement reference electrode potential difficulty. The technical effects achieved are as follows: the device solves the problem that the reference electrode of the miniature electrochemical sensor is difficult to directly measure the electrode potential, and further solves the problems of reduced measurement precision and limited service life of the sensor caused by the degradation and drift of the reference electrode.

Description

Reference electrode potential measuring and calculating device of miniature electrochemical sensor

Technical Field

The utility model relates to a sensor technical field, concretely relates to miniature electrochemical sensor reference electrode potential measuring and calculating device.

Background

The electrochemical sensor is a sensor for sensing and detecting based on the electrochemical property of an object to be detected and converting the chemical quantity of the object to be detected into electric quantity, and the electrochemical property of the object to be detected is characterized by measuring the change of electric signals such as electric potential, current and the like generated in the target electrochemical reaction when in use.

Among many sensor types, the electrochemical sensor has the advantages of relatively small size, low power consumption, simple structure, low cost, etc., and has gradually become the key point of the research field and wide application range. But it also has the problems of measurement drift, measurement accuracy degradation, need of regular calibration and maintenance, etc. With further miniaturization, miniaturization and intellectualization of the electrochemical sensor, the electrochemical sensor can be more widely applied to the fields of scientific research, medical treatment, industry, national defense, environment and the like.

Electrochemical sensors are typically composed of an electrode assembly, an electrolyte, and a permeable membrane. The electrode assembly may employ 2 electrodes (2 electrode system) or 3 electrodes (3 electrode system), including a reference electrode (reference electrode), a working electrode (working electrode), and sometimes an auxiliary electrode (counter electrode). The reference electrode is typically used to provide a known solution potential, and is typically of the type used such as a standard hydrogen electrode, calomel electrode, and most typically a silver/silver chloride electrode. The working electrode is typically made of an inert metal, such as platinum, gold, etc. The auxiliary electrode is also typically made of an inert metal, but the electrode area needs to be much larger than the working electrode. The electrolyte provides an ion-exchangeable environment that enables the targeted electrochemical reaction (redox reaction) to occur and efficiently transfer ionic charges to the electrodes. The electrolyte environment needs to remain stable and compatible with the electrode material, forming a stable reference potential with the reference electrode. The change in the electrolyte ion concentration directly affects the stability of the reference potential and thus the actual measurement result. In addition, in order to control the interference caused by other substances or reactions, some electrochemical sensors incorporate a filter membrane (gas permeable membrane) to selectively pass the substance to be detected and generate the target electrochemical reaction.

Electrochemical sensors generally employ chronoamperometry, in which an electrode assembly is in the same electrolyte solution, and when a specific voltage is applied to a working electrode and a reference electrode between the electrode assemblies, a target electrochemical reaction occurs in the electrode assembly, thereby generating a certain current between the electrodes. This reaction current is directly related to the reaction rate in solution, specifically to the rate of diffusion of the dissolved molecules to the surface of the working electrode, determined by its diffusion model, and is generally linear. The diffusion model is related to the concentration of ions to be measured and the shape and size of the electrode. Therefore, a specific voltage is applied to the sensor electrode, the reaction current is measured, and a specific target concentration value can be obtained after calibration calculation. Typical sensors are for example dissolved oxygen concentration sensors.

In addition, some electrochemical sensors characterize physical quantities by measuring the potential difference between electrodes. Such sensors typically employ a selective electrode for a particular ion as a working electrode, in combination with a reference electrode to form an electrode assembly. The electrode potential is the potential difference between the plate and the solution in the electrode, and different types of electrodes will have different potentials. The reference electrode can be generally considered to have stable potential and does not change along with the change of the measurement environment, but the working electrode can generate different potentials in solutions with different ion concentrations, so that the potential difference between the working electrode and the reference electrode is measured by comparing with the reference electrode, and the concentration value of the ions to be measured in the solution can be obtained after calibration calculation.

As mentioned above, the performance and stability of a micro electrochemical sensor is related to a number of factors, among which is directly related to the state, properties, stability of the reference electrode. Whether chronoamperometry or electrode potential difference is used to measure the characterizing physical quantity, a stable reference electrode is required as the reference potential. The chronoamperometry requires that a specific voltage signal is applied to the sensor (between the working electrode and the reference electrode) based on the potential of the reference electrode, and the electrode potential fluctuation of the reference electrode can cause the potential applied to the working electrode to fluctuate and drift, thereby directly influencing the occurrence of target reaction and finally causing the error of the measurement result. As shown in fig. 3, which is a graph of the current/voltage relationship of the reaction between the electrodes of the dissolved oxygen sensor, it can be seen that when the voltage between the electrodes of the sensor is in different ranges, different reactions occur, and thus the reaction current changes to a certain extent, resulting in measurement errors.

The sensor based on electrode potential difference measurement is closely connected with the potential of a reference electrode, such as a commonly used pH sensor (pH value sensor), namely, a voltage signal of a working electrode in a target solution environment relative to the potential of the reference electrode is directly measured, then the pH value is obtained through calibration calculation, and the fluctuation drift of the potential of any reference electrode can directly influence the calculation result. Such as a metal oxide based pH sensor, has a response sensitivity of-59.6 mV/pH,

if the reference electrode produces a potential change of + -10 mV, it will cause an error of + -0.17 pH; if the reference electrode produces a potential change of + -30 mV, an error of over + -0.5 pH will occur.

From the above, it can be seen how important a stable reference electrode is in the design of electrochemical sensors, especially micro electrochemical sensors, and it is also very meaningful to adjust the driving circuit of the electrochemical sensor or calibrate and compensate the measured result by knowing the electrode potential of the reference electrode if a stable reference electrode is not obtained.

However, in the actual use process, the reference electrode is influenced by the environment, and is degraded to a certain extent, so that fluctuation and drift of the electrode potential are caused. Particularly, the reference electrode in the micro electrochemical sensor has a limited volume, so that it is difficult to use a reference electrode having a large area and a large thickness, and thus the stability of the electrode potential is limited.

Such as a silver/silver chloride reference electrode commonly used in miniature electrochemical sensors, the surface of which undergoes a redox reaction, as shown below. The equilibrium is between silver metal (Ag) and its salt, silver chloride (AgCl), maintaining a relatively stable electrode potential.

The potential of the silver | silver chloride reference electrode can be calculated by the Nernst equation where the standard electrode potential (E0) is 0.230V + -10 mV relative to the Standard Hydrogen Electrode (SHE).

It can be seen that the silver/silver chloride reference electrode potential is linked to the ion concentration in the external environment, and in addition, the electrode potential changes with the change of the environmental temperature. As shown in FIG. 4, FIG. 5 and the following table, the ordinate in FIG. 4 is the Ag/AgCl electrode potential (V), the abscissa in FIG. 4 is the ambient Cl-ion concentration (mol/kg), the ordinate in FIG. 5 is the Ag/AgCl electrode potential (V), and the abscissa in temperature (. degree. C.).

In the design of the miniature electrochemical sensor, the stability of the silver/silver chloride reference electrode is improved, the calibration process and times of the sensor are increased, and the stability of the sensor can be improved by directly measuring the electrode potential of the reference electrode. However, sometimes the electrode potential of the reference electrode cannot be measured, or the electrode potential of the reference electrode is difficult to measure directly, and it is a good idea to measure other related parameters indirectly and then calculate the electrode potential of the reference electrode. From the above, it is known that the concentration of Cl-ions and the temperature in the environment are two important references, the temperature can be measured by integrating a micro temperature sensor to further measure the temperature near the silver/silver chloride reference electrode, and the concentration of Cl-ions in the environment can be approximated by measuring the conductivity value of the surrounding solution. In practical application, the silver/silver chloride reference electrode is often packaged with a special electrolyte (such as KCl or NaCl solution) in a relatively closed container, and is connected with an environment to be measured through an ion permeable membrane or a porous substance to form an interface. The composition of the solution around the silver/silver chloride reference electrode is therefore relatively simple and stable, and the ionic composition related to the solution conductivity is closely related to the concentration of Cl "ions in the solution, so that the influencing factor parameter between the solution conductivity and the electrode potential can be further determined by calibration measurements. The electrode potential of the target silver/silver chloride reference electrode can be determined by measuring the temperature and conductivity in the vicinity of the reference electrode, followed by calibration and calculation.

The miniaturized electrochemical sensors described in the references generally have glass electrodes or flat electrodes made by photolithography, but they are subject to the problem of limited sensor volume and the problem of fluctuations and drift of the reference electrodes. Calibration needs to be performed periodically, manual intervention is required for calibration, and an external calibration device needs to be used. Direct measurement of the electrode potential of the reference electrode is also difficult, requiring the introduction of an additional stable reference electrode, and associated test circuitry, which can be difficult to implement in certain sensor designs and applications.

The references are as follows:

utility model patent application: miniature electrochemical sensor based on direct forming mesoporous carbon technology and manufacturing method

Application publication No.: CN104502428A

Utility model patent application: multi-parameter water quality monitoring integrated microarray electrode and preparation method thereof

Application publication No.: CN102495119A

Utility model patent application: electrochemical sensor for detecting blood enzyme

Application publication No.: CN111638256A

Utility model patent application: dissolved oxygen electrochemical sensor

Application publication No.: CN101042365A

Polarography dissolved oxygen sensor

https://www.mt.com/hk/zh/home/products/Process-Analytics/DO-CO2-ozone-sensor/dissolved-oxygen-meter/polarographic-dissolved-oxygen-sensor.html

Utility model patent application: integrated micro-nano sensor and manufacturing method thereof

Application publication No.: CN109813778A

Utility model patent application: novel multifunctional sensor chip and preparation method thereof

Application publication No.: CN106959169B

In summary, the prior art has the following problems:

firstly, due to the fact that the volume and the area of the miniature electrochemical sensor are limited, the area of the reference electrode is small, the volume is limited, the stability of the reference potential is not high when the miniature electrochemical sensor is used for measurement, potential drift exists, and the service life is limited.

Secondly, during the actual use of the reference electrode, periodic calibration is required, or the electrode potential of the reference electrode is measured, so that the measurement error is reduced.

Third, a reference electrode with an external reference is required for calibration.

Fourth, calibration requires the user to calibrate the reference electrode and no simultaneous experiments or measurements can be made.

Fifth, it is difficult to adjust the sensor driving circuit or perform calibration compensation on the measurement result by directly measuring the electrode potential of the reference electrode.

SUMMERY OF THE UTILITY MODEL

Therefore, the utility model provides a miniature electrochemical sensor reference electrode potential measuring device to solve the above-mentioned problem among the prior art.

In order to achieve the above object, the present invention provides the following technical solutions:

according to the utility model discloses an aspect, a miniature electrochemical sensor reference electrode potential measuring device, including airtight casing, reference electrode, temperature sensor, conductivity sensor, measuring circuit and working electrode and other sensor electrode that probably use, be provided with reference electrode, temperature sensor and conductivity sensor in the airtight casing, reference electrode, temperature sensor, conductivity sensor and working electrode and other sensor electrode that probably use all are connected with each measuring circuit electricity through the connecting wire.

Further, the electrolyte is filled in the sealed shell and used for maintaining the stability of the reference electrode.

Furthermore, the device also comprises a small hole, and the bottom end of the closed shell is provided with the small hole.

Further, the device also comprises a communicating interface, wherein the communicating interface is arranged on the small hole, and the communicating interface is one of a breathable film or a porous substance.

Further, the measuring circuit comprises a conductivity measuring circuit, a temperature measuring circuit and an electrochemical sensor measuring circuit, wherein the temperature sensor is electrically connected with the temperature measuring circuit, the conductivity sensor is electrically connected with the conductivity measuring circuit, and the reference electrode, the temperature measuring circuit, the conductivity measuring circuit and the working electrode and other possible sensor electrodes are electrically connected with the electrochemical sensor measuring circuit.

Furthermore, the device also comprises a reference electrode calibration circuit, and the conductivity measurement circuit, the temperature measurement circuit and the electrochemical sensor measurement circuit are all electrically connected with the reference electrode calibration circuit.

Further, the conductivity sensor is a contact conductivity sensor or an inductive conductivity sensor.

Furthermore, the device also comprises a sensor chip, wherein the sensor chip is arranged in the closed shell, and the reference electrode, the temperature sensor and the conductivity sensor are integrated on the sensor chip.

Further, the chip comprises a chip substrate, and the chip is arranged on the chip substrate.

Furthermore, the temperature sensor is formed by a platinum wire thermistor evaporated on the substrate, and the shape of the temperature sensor is in a reciprocating wave shape.

The utility model has the advantages of as follows: firstly, the device solves the problems of reduced sensor measurement accuracy and limited service life caused by the problems of degradation and drift of the reference electrode of the miniature electrochemical sensor. The electrode potential of the reference electrode of the sensor is measured, so that the self-calibration of the potential of the reference electrode is realized, the measurement precision of the sensor is maintained as much as possible, and the service life is prolonged; secondly, certain related indirect parameters are measured, and then the electrode potential of the reference electrode is calculated; thirdly, the self-calibration function of the reference electrode is realized by obtaining the electrode potential of the reference electrode, namely the electrode potential of the reference electrode can be used for adjusting a sensor driving circuit or calibrating and compensating a measurement result; and fourthly, the self-calibration function of the reference electrode can be realized, the real-time or timed self-calibration of the reference electrode can be realized without an external device, the intervention of a user is not needed, and the self-calibration module can be directly fed back to a measurement circuit of the sensor, so that the calibration work can be carried out without suspending experiments or measurement.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. It should be apparent that the drawings in the following description are merely exemplary, and that other embodiments can be derived from the drawings provided by those of ordinary skill in the art without inventive effort.

The structure, ratio, size and the like shown in the present specification are only used for matching with the content disclosed in the specification, so as to be known and read by people familiar with the technology, and are not used for limiting the limit conditions which can be implemented by the present invention, so that the present invention has no technical essential significance, and any structure modification, ratio relationship change or size adjustment should still fall within the scope which can be covered by the technical content disclosed by the present invention without affecting the efficacy and the achievable purpose of the present invention.

Fig. 1 is a schematic structural diagram of a reference electrode potential measuring device of a micro electrochemical sensor according to some embodiments of the present invention.

Fig. 2 is a schematic diagram of a second structure of a reference electrode potential measuring device of a micro electrochemical sensor according to some embodiments of the present invention.

FIG. 3 is a graph showing a current/voltage relationship of a reaction between electrodes of a dissolved oxygen sensor according to the prior art.

FIG. 4 is a graph of the potential of a prior art Ag/AgCl reference electrode as a function of temperature at different Cl-ion concentrations.

FIG. 5 is a graph of the potential of a prior art Ag/AgCl reference electrode as a function of temperature at different Cl-ion concentrations.

In the figure: 1. the electrochemical sensor comprises a reference electrode, 2, a closed shell, 3, an electrolyte, 4, a communication interface, 5, a temperature sensor, 6, a conductivity sensor, 7, a temperature measuring circuit, 8, a conductivity measuring circuit, 9, a reference electrode calibration circuit, 10, an electrochemical sensor measuring circuit, 11 and a working electrode.

Detailed Description

The present invention is described in terms of specific embodiments, and other advantages and benefits of the present invention will become apparent to those skilled in the art from the following disclosure. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

As shown in fig. 1 and fig. 2, the reference electrode potential measuring device for a miniature electrochemical sensor in the embodiment of the first aspect of the present invention includes a sealed housing 2, a reference electrode 1, a temperature sensor 5, a conductivity sensor 6, a measuring circuit, a working electrode and other sensor electrodes 11 that may be used, the reference electrode 1, the temperature sensor 5 and the conductivity sensor 6 are disposed in the sealed housing 2, and the reference electrode 1, the temperature sensor 5, the conductivity sensor 6 and the working electrode 11 are all electrically connected to the measuring circuit through connecting wires.

In the above embodiments, it should be noted that the reference electrode 1 may be a silver/silver chloride reference electrode; the temperature sensor 5 is integrated in the vicinity of the reference electrode 1, and enables measurement of the temperature in the vicinity of the reference electrode 1. The temperature sensor 5 is not limited to a thermistor, a thermocouple, or the like for measuring temperature. The conductivity sensor 6 is integrated in the vicinity of the reference electrode, enabling the measurement of the conductivity value of the solution in the vicinity of the reference electrode 1.

The technical effects achieved by the above embodiment are as follows: the device integrates a temperature sensor 5 and a conductivity sensor 6 near the reference electrode 1, and the concentration of ions is calculated by measuring the temperature of the surrounding environment of the reference electrode 1 and the conductivity of the solution, so that the potential of the reference electrode 1 is calculated. The updated potential of the reference electrode 1 is fed back to the measuring circuit, so that the normal work and the measuring precision of the electrochemical sensor are ensured.

Preferably, as shown in fig. 1 and 2, in some embodiments, the reference electrode further includes an electrolyte 3, the electrolyte 3 is filled in the hermetic case 2, and the electrolyte 3 is used for maintaining the stability of the reference electrode 1.

The beneficial effects of the preferred embodiment are as follows: the electrolyte 3 is arranged so that the potential of the reference electrode 1 is stabilized.

In the above preferred embodiment, it should be noted that the electrolyte 3 is a KCl solution or a NaCl solution, and some of the electrolytes 3 are also doped with silver chloride; wherein, the sealed shell 2 is also filled with a reticular porous structure such as electrolyte colloid, sponge or filter paper, etc., which further stabilizes ions in the electrolyte 3 and weakens ion diffusion with the external environment.

Preferably, as shown in fig. 1 and 2, in some embodiments, the sealing device further includes a small hole, and the bottom end of the sealing housing 2 is provided with the small hole.

The beneficial effects of the preferred embodiment are as follows: the reference electrode 1 is communicated with an external substance to be measured through the arrangement of the small holes.

In the above preferred embodiment, it should be noted that the sealed case 2 is connected with the electrolyte in the sensor body through a small hole or a porous substance to establish an ion channel.

Preferably, as shown in fig. 1 and 2, in some embodiments, the device further includes a communication interface 4, and the communication interface 4 is disposed on the small hole.

The beneficial effects of the preferred embodiment are as follows: the communication interface 4 is used for realizing the communication between the reference electrode 1 and the external substance to be measured.

In the above preferred embodiment, the communication interface 4 is a gas permeable film or a porous material.

Preferably, as shown in fig. 1 and 2, in some embodiments, the measuring circuit includes a conductivity measuring circuit 8, a temperature measuring circuit 7, and an electrochemical sensor measuring circuit 10, the temperature sensor 5 is electrically connected to the temperature measuring circuit 7, the conductivity sensor 6 is electrically connected to the conductivity measuring circuit 8, and the reference electrode 1, the temperature measuring circuit 7, the conductivity measuring circuit 8, and the working electrode, and possibly other sensor electrodes 11, are electrically connected to the electrochemical sensor measuring circuit 10.

The beneficial effects of the preferred embodiment are as follows: the temperature measuring circuit 7 is arranged to measure and drive the temperature fed back by the temperature sensor 5, and the measurement result is fed back to the system, and the conductivity measuring circuit 8 is arranged to measure and drive the conductivity sensor 6, and the measurement result is fed back to the system.

In the above preferred embodiment, it should be noted that the reference electrode 1 and the working electrode and other possible sensor electrodes 11 and other possible electrodes are connected to the electrochemical sensor measuring circuit 10. The electrochemical sensor measurement circuit 10 may be configured by a user to achieve a particular drive waveform for different electrochemical sensors to achieve a measurement. Meanwhile, the driving signal of the electrochemical sensor can be adjusted or the measurement result can be adjusted and calibrated according to the input of the reference electrode calibration circuit.

Preferably, as shown in fig. 1 and 2, in some embodiments, a reference electrode calibration circuit 9 is further included, and the conductivity measurement circuit 8, the temperature measurement circuit 7, and the electrochemical sensor measurement circuit 10 are all electrically connected to the reference electrode calibration circuit 9.

The beneficial effects of the preferred embodiment are as follows: firstly, the device realizes the self-calibration function of the reference electrode through the arrangement of the electrochemical sensor measuring circuit 10 and the reference electrode calibration circuit 9, and the latest potential of the reference electrode 1 can be updated into the system in each calibration along with the gradual drift of the reference electrode 1; secondly, the self-calibration function of the reference electrode 1 of the device realizes the self-calibration of the reference electrode in real time or in a timing manner without an external device, the intervention of a user is not needed, and the calibration result can be directly fed back to the electrochemical sensor measuring circuit 10 by the reference electrode calibration circuit 9, so that the calibration work can be carried out without suspending experiments or measuring.

In the above preferred embodiment, it should be noted that both the conductivity measurement circuit 8 and the temperature measurement circuit 7 feed back the obtained measurement result and signal to the reference electrode calibration circuit 9, and the feedback signals of the conductivity measurement circuit 8 and the temperature measurement circuit 7 may be digital signals, and directly feed back the measured temperature and conductivity values, or may be analog signals after signal conditioning, and directly feed back the analog signals to the reference electrode calibration circuit 9.

Preferably, in some embodiments, the conductivity sensor 6 is a contact conductivity sensor or an inductive conductivity sensor.

In the above preferred embodiment, it should be noted that when the conductivity sensor 6 is a contact sensor, a multi-electrode contact sensor may be used, the multi-electrode forms an electrode group, and the electrode group may be two electrodes, four electrodes, seven electrodes, or the like.

Preferably, in some embodiments, the sensor device further comprises a sensor chip, the sensor chip is arranged inside the closed shell 2, and the reference electrode 1, the temperature sensor 5 and the conductivity sensor 6 are integrated on the sensor chip.

The beneficial effects of the preferred embodiment are as follows: the reference electrode 1, the temperature sensor 5 and the conductivity sensor 6 are integrated on the same sensor chip, so that the temperature and conductivity values of the solution near the reference electrode 1 are measured.

Preferably, in some embodiments, the reference electrode 1, the temperature sensor 5 and the conductivity sensor 6 are disposed on a chip substrate.

The beneficial effects of the preferred embodiment are as follows: the arrangement of the chip substrate provides reliable mounting positions for the reference electrode 1, the temperature sensor 5 and the conductivity sensor 6.

In the above preferred embodiment, it should be noted that the substrate of the chip may be glass or silicon wafer.

Preferably, in some embodiments, the temperature sensor 5 is formed by a platinum thermistor deposited on the chip substrate, and the shape of the temperature sensor 5 is a reciprocating wave shape.

The beneficial effects of the preferred embodiment are as follows: the arrangement of the temperature sensor 5 in a reciprocating wave shape realizes that the length of the platinum wire is increased under a specific area, the width of the platinum wire is controlled, and thus, a specific resistance value is realized.

Although the invention has been described in detail with respect to the general description and the specific embodiments, it will be apparent to those skilled in the art that modifications and improvements can be made based on the invention. Therefore, such modifications and improvements are intended to be within the scope of the invention as claimed.

In the present specification, the terms "upper", "lower", "left", "right", "middle", and the like are used for the sake of clarity only, and are not intended to limit the scope of the present invention, and changes or adjustments of the relative relationship thereof are also considered to be the scope of the present invention without substantial changes in the technical content.

Claims

1. The potential measuring and calculating device for the reference electrode of the miniature electrochemical sensor is characterized by comprising a closed shell (2), the reference electrode (1), a temperature sensor (5), a conductivity sensor (6), a measuring circuit and a working electrode (11), wherein the reference electrode (1), the temperature sensor (5) and the conductivity sensor (6) are arranged in the closed shell (2), and the reference electrode (1), the temperature sensor (5), the conductivity sensor (6) and the working electrode (11) are electrically connected with the measuring circuit through connecting wires.

2. The reference electrode potential measuring device of the miniature electrochemical sensor according to claim 1, further comprising an electrolyte (3), wherein the electrolyte (3) is filled in the sealed housing (2), and the electrolyte (3) is used for maintaining the stability of the reference electrode (1).

3. The reference electrode potential measuring device of the miniature electrochemical sensor as claimed in claim 1, further comprising a small hole, wherein the small hole is opened at the bottom end of the closed shell (2).

4. The reference electrode potential measuring device of the micro electrochemical sensor according to claim 3, further comprising a communication interface (4), wherein the communication interface (4) is disposed on the small hole.

5. The reference electrode potential estimation device of the miniature electrochemical sensor according to claim 1, wherein the measuring circuit comprises a conductivity measuring circuit (8), a temperature measuring circuit (7) and an electrochemical sensor measuring circuit (10), the temperature sensor (5) is electrically connected with the temperature measuring circuit (7), the conductivity sensor (6) is electrically connected with the conductivity measuring circuit (8), and the reference electrode (1), the temperature measuring circuit (7), the conductivity measuring circuit (8) and the working electrode (11) are electrically connected with the electrochemical sensor measuring circuit (10).

6. The reference electrode potential estimation device of the miniature electrochemical sensor according to claim 5, further comprising a reference electrode calibration circuit (9), wherein the conductivity measurement circuit (8), the temperature measurement circuit (7) and the electrochemical sensor measurement circuit (10) are electrically connected to the reference electrode calibration circuit (9).

7. The reference electrode potential estimation device of the miniature electrochemical sensor according to claim 1, wherein the conductivity sensor (6) is a contact conductivity sensor or an inductive conductivity sensor.

8. The reference electrode potential measuring and calculating device of a miniature electrochemical sensor according to claim 1, further comprising a sensor chip, wherein said sensor chip is disposed inside said closed shell (2), and said reference electrode (1), said temperature sensor (5) and said conductivity sensor (6) are integrated on said sensor chip.

9. The reference electrode potential measuring device of the micro electrochemical sensor as claimed in claim 8, further comprising a chip substrate, wherein the chip is disposed on the chip substrate.

10. The reference electrode potential measuring device of the miniature electrochemical sensor as claimed in claim 9, wherein the temperature sensor (5) is formed by a platinum thermistor vapor-deposited on the chip substrate, and the shape of the temperature sensor (5) is a reciprocating wave shape.