Device and method for monitoring gas concentration and sensor

Abstract

The present invention discloses a device, method and sensor for monitoring gas concentration, wherein the device includes a sensing device and a processing device, the sensing device includes a first selective water-permeable membrane layer, a first sensing electrode and a second sensing electrode, wherein the first selective water-permeable membrane layer is used to allow the first sensing electrode to contact water molecules but not contact gas molecules to be measured, the first sensing electrode is used to generate an electrical signal caused by humidity changes, and the second sensing electrode is used to generate a superimposed electrical signal caused by humidity changes and gas molecules to be measured; the processing device is used to obtain the concentration of the gas to be measured based on the electrical signal caused by humidity changes and the superimposed electrical signal. The sensor, device and method of the present invention can quickly and effectively perform environmental temperature and humidity correction, thereby accurately calculating the concentration of the gas to be measured.

Description

Technical Field

[0001] The present invention relates to the technical field of atmosphere monitoring, and in particular to a device for monitoring gas concentration, a sensor for monitoring gas concentration, and a method for monitoring gas concentration. Background Art

[0002] Accurately measuring the concentration of atmospheric pollutants and accurately outlining the distribution patterns of atmospheric pollutants with ultra-high temporal and spatial resolution are becoming the main work directions for atmospheric pollution prevention and control, such as locating pollution sources and monitoring emission characteristics, improving air quality, and studying the health effects of humans caused by exposure to atmospheric pollutants.

[0003] To achieve the above monitoring objectives, miniaturized gas sensors, such as metal oxide semiconductor sensors and electrochemical sensors, must be used. However, miniaturized gas sensors, such as electrochemical sensors, are generally used to monitor air pollutants at the ppm (part per million) concentration level, and their main purpose is to provide early warning for safe production. 2 、Ozone 3 and sulfur dioxide SO 2 ) concentration is generally less than 1ppm, some gases such as NO 2 and O 3 Its common concentration range is only a few ppb (part per billion) to dozens of ppb, generally not exceeding 200 ppb, which means that the sensitivity of traditional small gas sensors is not enough to detect the concentration of air pollutants in outdoor environments.

[0004] In recent years, electrochemical sensors have gradually reached ppb-level sensitivity by increasing the electrode surface area and reducing the electronic noise of the supporting circuit. However, changes in environmental temperature and humidity will cause changes in the electrode voltage of the electrochemical sensor, and this voltage change will be superimposed on the target electrical signal generated by the electrochemical redox reaction of the gas on the electrode surface, interfering with gas measurement. When the concentration of the gas to be measured is at the ppb level, the electrochemical reaction signal of the gas is very weak. In comparison, the so-called baseline change caused by the change in temperature and humidity of the sensor environment cannot be ignored and must be correctly corrected. The current correction methods for the change in sensor baseline signal caused by temperature and humidity changes mainly include single variable or multivariate linear regression methods, machine learning, artificial neural networks or high-dimensional model characterization methods, but these methods all have some defects, such as black box operation, not reflecting the real physical laws, complex algorithms, large deviations in calculated concentration results, and low versatility. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, one object of the present invention is to provide a device for monitoring gas concentration, which can quickly and effectively perform environmental temperature and humidity correction, so as to accurately calculate the gas concentration.

[0006] A second object of the present invention is to provide a sensor for monitoring gas concentration.

[0007] The third object of the present invention is to provide a method for monitoring gas concentration.

[0008] In order to achieve the above-mentioned purpose, an apparatus for monitoring gas concentration according to an embodiment of the first aspect of the present invention comprises a sensing device and a processing device, wherein the sensing device comprises a first selective water-permeable membrane layer, a first sensing electrode and a second sensing electrode, wherein the first selective water-permeable membrane layer is used to allow the first sensing electrode to contact with water molecules but not with gas molecules to be measured, the first sensing electrode is used to generate an electrical signal caused by a change in humidity, and the second sensing electrode is used to generate a superimposed electrical signal caused by a reaction between a change in humidity and gas molecules to be measured; and the processing device is used to obtain the concentration of the gas to be measured based on the electrical signal caused by the change in humidity and the superimposed electrical signal.

[0009] The device for monitoring gas concentration of the embodiment of the present invention proposes a new method for monitoring gas concentration. The sensing device is provided with a first selective water-permeable membrane layer, a first sensing electrode and a second sensing electrode. The first sensing electrode detects the electrical signal caused by humidity change, and the second sensing electrode detects the superimposed electrical signal caused by the reaction between humidity change and gas molecules to be measured. The humidity electrical signal is separated by the first selective water-permeable membrane layer, and the processing device can deduct the temperature-related term, the humidity-related term, and the baseline-related term from the superimposed electrical signal to obtain the electrical signal associated with the gas molecules to be measured, thereby quickly and effectively performing environmental temperature and humidity correction, accurately determining the concentration of the gas to be measured, and having high versatility.

[0010] In some embodiments, the sensing device includes a first sensor and a second sensor, the first sensor includes the first sensing electrode, the second sensor includes the second sensing electrode, the first sensing electrode is connected to the outside world through the sensing surface of the first sensor, and the second sensing electrode is connected to the outside world through the sensing surface of the second sensor; wherein the first selective water-permeable membrane layer is arranged on the sensing surface of the first sensor and completely covers the sensing surface, or the first selective water-permeable membrane layer is arranged on the surface of the first sensing electrode;

[0011] In some embodiments, the sensing device further includes: a second selectively water-permeable membrane layer, wherein the second selectively water-permeable membrane layer is used for not covering the sensing surface of the second sensor or not covering the sensing surface portion of the second sensing electrode connected to the outside world when monitoring gas concentration, and, when calibrating the coefficient, covering the sensing surface of the second sensor or covering the sensing surface portion of the second sensing electrode connected to the outside world.

[0012] In some embodiments, the sensing device includes: a sensor, the sensor including the first sensing electrode and the second sensing electrode, the first sensing electrode and the second sensing electrode are connected to the outside world through the sensing surface of the sensor, wherein the first selective water permeable membrane layer is arranged on the surface of the first sensing electrode, or the first selective water permeable membrane layer is arranged on the sensing surface portion of the first sensing electrode connected to the outside world; the first selective water permeable membrane layer is also used for not covering the sensing surface portion of the second sensing electrode connected to the outside world when monitoring gas concentration, and covering the sensing surface portion of the second sensing electrode connected to the outside world when calibrating the coefficient.

[0013] In some embodiments, the sensing device further includes: a second selectively water-permeable membrane layer, the second selectively water-permeable membrane layer being used for not covering the sensing surface portion of the second sensing electrode of one of the sensors connected to the outside world when monitoring gas concentration, and covering the sensing surface portion of the second sensing electrode connected to the outside world when calibrating the coefficient.

[0014] In order to achieve the above object, a sensor for monitoring gas concentration according to an embodiment of the present invention comprises:

[0015] Sensor body;

[0016] a first sensor electrode and a first selective water-permeable membrane layer, wherein the first sensor electrode is disposed on the sensor body and is connected to the outside world through a sensing surface;

[0017] Wherein, the first selective water-permeable membrane layer is arranged on the sensing surface of the first sensing electrode connected to the outside world and completely covers the sensing surface portion of the first sensing electrode connected to the outside world, so that the first sensing electrode can contact with water molecules but not with the gas molecules to be measured, so as to generate the electrical signal change characteristics caused by the humidity change; or, the first selective water-permeable membrane layer is arranged on the surface of the first sensing electrode, so that the first sensing electrode can contact with water molecules but not with the gas molecules to be measured, so as to generate the electrical signal change characteristics caused by the humidity change.

[0018] According to the sensor for monitoring gas concentration of an embodiment of the present invention, by setting a first selective water-permeable membrane layer, the first sensing electrode can be in contact with water molecules only to generate a humidity electrical signal, and the electrical signal generated by humidity changes can be separated to provide data support for monitoring the concentration of the gas to be measured.

[0019] In some embodiments, the sensor also includes a second sensing electrode arranged in the sensor body, and the second sensing electrode is connected to the outside world through the sensing surface; the first selective water permeable membrane layer is also used not to cover the sensing surface portion of the second sensing electrode connected to the outside world when monitoring gas concentration, and to cover the sensing surface portion of the second sensing electrode connected to the outside world when calibrating the coefficient.

[0020] In some embodiments, the sensor also includes a second sensing electrode arranged in the sensor body, and the second sensing electrode is connected to the outside world through the sensing surface; the sensor also includes a second selective water-permeable membrane layer, and the second selective water-permeable membrane layer is used for not covering the sensing surface of the second sensing electrode connected to the outside world or not covering the surface of the second sensing electrode when monitoring gas concentration, and covering the sensing surface of the second sensing electrode connected to the outside world or covering the surface of the second sensing electrode when calibrating the coefficient.

[0021] In order to achieve the above-mentioned purpose, the method for monitoring gas concentration of an embodiment of the present invention is used for the device for monitoring gas concentration, and the method includes: obtaining an electrical signal generated by humidity change and a superimposed electrical signal caused by humidity change and gas molecules to be measured; and obtaining the concentration of the gas to be measured based on the electrical signal and the superimposed electrical signal.

[0022] According to the method for monitoring gas concentration of an embodiment of the present invention, based on a selective water-permeable membrane layer, a first sensing electrode and a second sensing electrode, the humidity electrical signal caused by water molecules is separated, and then the temperature-related term and the humidity-related term are deducted from the superimposed electrical signal caused by the water molecules and the gas molecules to be measured to obtain the electrical signal associated with the gas molecules to be measured. The method can quickly and effectively perform environmental temperature and humidity correction, accurately determine the concentration of the gas to be measured, and has high versatility.

[0023] In some embodiments, the concentration of the gas to be measured is obtained according to the following formula:

[0024]

[0025] Alternatively, the sensing device includes a first sensor and a second sensor, the first sensor includes the first sensing electrode and a first auxiliary electrode, the second sensor includes the second sensing electrode and a second auxiliary electrode, and the concentration of the gas to be measured is obtained according to the following formula:

[0026]

[0027] Where [P](t) is the concentration of the gas to be measured, W 2 (t) is the detection signal of the second sensing electrode, W 1 (t) is the detection signal of the second auxiliary electrode, A 2 (t) is the detection signal of the first sensing electrode, A 1 (t) is the detection signal of the first auxiliary electrode, and a, b, c and s are empirical coefficients to be calibrated.

[0028] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0030] Figure 1 is a block diagram of an apparatus for monitoring gas concentration according to an embodiment of the present invention;

[0031] Figure 2 is a block diagram of an apparatus for monitoring gas concentration according to another embodiment of the present invention;

[0032] Figure 3 is a block diagram of an apparatus for monitoring gas concentration according to another embodiment of the present invention;

[0033] Figure 4 is a block diagram of an apparatus for monitoring gas concentration according to another embodiment of the present invention;

[0034] Figure 5 is a block diagram of a sensor for monitoring gas concentration according to one embodiment of the present invention;

[0035] Figure 6 is a block diagram of a sensor for monitoring gas concentration according to another embodiment of the present invention;

[0036] Figure 7 is a block diagram of a sensor for monitoring gas concentration according to another embodiment of the present invention;

[0037] Figure 8 is a block diagram of a sensor for monitoring gas concentration according to another embodiment of the present invention;

[0038] Fig. 9 is a flow chart of a method for monitoring gas concentration according to an embodiment of the present invention. DETAILED DESCRIPTION

[0039] Embodiments of the present invention are described in detail below. The embodiments described with reference to the accompanying drawings are exemplary. Embodiments of the present invention are described in detail below.

[0040] In the related art, the methods for monitoring gas concentration are optimized based on the functional relationship between the baseline signal change of the electrochemical sensor and the temperature and humidity of the environment. The algorithm is complex and similar to a black box operation, and it is difficult for users to intervene in the optimization process. It does not understand and explain the baseline drift caused by temperature and humidity from the real physical laws, and the obtained parameterized scheme cannot be truly explained by physical laws. In essence, it only builds and trains related algorithm models through measurement data over a period of time. The obtained algorithm is local and often cannot be applied to new measurement environments. In addition, due to the variety of temperature and humidity change trends in the natural environment, it is difficult to truly use parameterized mathematical formulas to nearly perfectly calculate the baseline drift signal of the electrochemical sensor caused by temperature and humidity in various environments, and the measurement results are inaccurate.

[0041] In response to the problems in the related art, the device and method for monitoring gas concentration in the embodiments of the present invention can accurately measure and deduct the baseline drift signal of the gas sensor caused by changes in ambient temperature and humidity, thereby achieving the purpose of accurately measuring the concentration of the gas to be measured in the environment.

[0042] Reference below Figure 1 An apparatus for monitoring gas concentration according to an embodiment of the present invention is described.

[0043] Figure 1 is a device for monitoring gas concentration according to an embodiment of the present invention, such as Figure 1 As shown, the device 1 according to the embodiment of the present invention includes a sensing device 10 and a processing device 20 .

[0044] The sensing device 10 at least comprises a first sensing electrode 11, a second sensing electrode 12 and a first selective water-permeable membrane layer 13. The first selective water-permeable membrane layer 13 is used to allow the first sensing electrode 11 to contact water molecules but not contact gas molecules to be measured; the first sensing electrode 11 is used to generate an electrical signal caused by humidity change, and the second sensing electrode 12 is in contact with water molecules and gas molecules to be measured, and is used to generate a superimposed electrical signal caused by humidity change and sensing reaction of gas molecules to be measured.

[0045] The processing device 20 is electrically connected to the sensing device 10, and is used to obtain detection signals from the first sensing electrode 11 and the second sensing electrode 12, and obtain the concentration of the gas to be measured based on the electrical signal caused by the humidity change output by the first sensing electrode 11 and the superimposed electrical signal caused by the humidity change and the gas molecules to be measured generated by the second sensing electrode 12.

[0046] Specifically, the sensing device 10 of the embodiment of the present invention may include an electrochemical gas sensor, a semiconductor sensor, and any other chemical and physical sensor that is affected by changes in ambient temperature and humidity, and no specific restrictions are made here. The device 1 for monitoring gas concentration of the embodiment of the present invention proposes a new way of monitoring gas concentration, by setting a first selective water-permeable membrane layer 13, a first sensing electrode 11, and a second sensing electrode 12, the first sensing electrode 11 mainly detects the humidity electrical signal caused by water molecules, the second sensing electrode 12 detects the superimposed electrical signal caused by water molecules and the gas molecules to be measured, and the humidity electrical signal is separated by the first selective water-permeable membrane layer 13, and the processing device 20 deducts the temperature-related term, the humidity-related term, and the baseline-related term from the superimposed electrical signal caused by the water molecules and the gas molecules to be measured to obtain the electrical signal associated with the gas molecules to be measured, so that the ambient temperature and humidity correction can be performed quickly and effectively, and the concentration of the gas to be measured can be accurately determined, and the versatility is high.

[0047] Furthermore, in order to make the first sensing electrode 11 contact with water molecules but not contact with the gas molecules to be measured, in the embodiment, this can be achieved by disposing a first selective water-permeable membrane layer 13 at the corresponding position of the sensor. The first selective water-permeable membrane layer 13 can be understood as one or more membrane layers that only allow water molecules to selectively permeate, and can basically block the gas molecules to be measured from permeating, that is, the permeability of the membrane layer to water molecules is much greater than the permeability of the gas molecules to be measured.

[0048] In some embodiments, Figure 2 As shown, the sensing device 10 includes two sensors, namely a first sensor 101 and a second sensor 102. The first sensor 101 includes a first sensing electrode 11, and the first sensing electrode 11 is connected to the outside through the sensing surface of the first sensor 101. The first selective water-permeable membrane layer 13 is arranged on the sensing surface of the first sensor 101 and covers the first sensing electrode 11, for example, a selective water-permeable membrane is attached to the sensing surface, so that the first sensing electrode 11 in the first sensor 101 can only contact with water molecules, which is used to generate an electrical signal caused by humidity changes, and transmit the humidity electrical signal and the detection signal of the first auxiliary electrode 15 to the processing device 20, so as to provide data support for monitoring the concentration of the gas to be measured. Among them, the sensing surface can be understood as the side of the sensor where the external gas molecules enter the sensor.

[0049] Taking electrochemical sensors as an example, in order to provide the performance of electrochemical sensors, four electrodes can be used, such as a sensing electrode, an auxiliary electrode, a counter electrode, and a reference electrode. Among them, the sensing electrode oxidizes or reduces the target gas, the counter electrode balances the generated current, the reference electrode anchors the work at the correct potential, and the auxiliary electrode compensates the zero current. There is no current flowing between the reference electrode and the sensing electrode, so the potential of the sensing electrode always remains consistent with that of the reference electrode.

[0050] Specifically, a thin film that only allows water molecules to selectively penetrate is covered on the sensing surface of the electrochemical sensor. External gas molecules must pass through the thin film to enter the sensor. The thickness of the film can be from a few microns to several hundred microns, but the premise is that, compared with the sensor without the film on the sensing surface, its presence does not significantly slow down the diffusion of water molecules in and out of the sensor, but at the same time it can completely isolate the gas molecules to be measured, making it impossible for them to enter the sensor. To achieve this goal, the film used has the following characteristics: water molecules have a strong diffusion ability inside the film, so that the first sensing electrode 11 can effectively sense changes in external humidity to generate humidity electrical signals caused by water molecules, but the diffusion coefficient of the gas to be measured in the film is extremely low, so the first sensing electrode 11 has no response to the target gas to be monitored.

[0051] Different from the solutions in the related art, in which a semi-permeable membrane is used to pass the gas to be measured and filter out interfering components, the present application uses a first selective water-permeable membrane to pass water and filter out other components, wherein water is an interfering component relative to the gas to be measured.

[0052] In an embodiment, the first selective water-permeable membrane layer may be, but is not limited to, a proton exchange membrane, a polymer semipermeable membrane that can pass water and filter other components, such as a SPEEK (Sulfonated polyetheretherketon) membrane layer, a PEO-PBT (poly(ethylene oxide)–poly(butylene terephthalate) membrane layer, a poly-dopamine membrane layer, a Polyether block amide membrane layer, etc., as well as other membrane layers that can achieve selective water-permeable membrane layer performance through modification.

[0053] Preferably, a proton exchange membrane is used, which has a barrier effect on the gas molecules to be measured and a conductive effect on the water molecules. The proton exchange membrane mainly includes perfluorosulfonic acid proton exchange membrane, non-fluorinated polymer proton exchange membrane, novel composite proton exchange membrane, etc., wherein the perfluorinated treatment is mainly to make the membrane have better anti-oxidation, aging and chemical corrosion capabilities, so the perfluorinated membrane generally has a longer service life. For example, applicable perfluorosulfonic acid proton exchange membranes include Nafion membranes, DOW membranes, Xus-B204 membranes, Aciplex membranes, Flemion membranes, Gore-Select membranes and Dongyue membranes, etc. The good diffusion performance of water molecules in the proton transfer exchange membrane mainly comes from the strong intermolecular interaction between water molecules and the hydrophilic groups in the membrane (such as the sulfonic acid groups in the perfluorosulfonic acid proton transfer exchange membrane), and most other inorganic molecules are described below. Important atmospheric pollution gas molecules cannot form intermolecular interactions of sufficient strength with these hydrophilic groups, so they cannot effectively diffuse to the working electrode surface through the membrane layer to generate signals by electrochemical reactions.

[0054] Taking Nafion proton transfer exchange membrane as an example, many important atmospheric pollutants, such as NO, NO 2 、SO 2 , CO and O 3 etc., because of their extremely low diffusion coefficients, they cannot effectively penetrate the Nafion proton transfer exchange membrane and cannot react on the surface of the sensor electrode to generate electrical signals. However, water molecules can quickly diffuse through the membrane, so the electrical signals caused by changes in external relative humidity can still be effectively recorded by the sensor.

[0055] The selective water-permeable membrane layer of the embodiment of the present invention is not limited to Nafion membrane, and any other proton exchange membrane or a membrane that can selectively permeate water molecules but cannot permeate the gas to be measured can be used as the first selective water-permeable membrane layer.

[0056] Furthermore, the first sensor 101 cannot contact the gas to be measured due to the first selective water-permeable membrane layer 13 being set on the sensing surface, and will not be able to achieve the purpose of measurement. The second sensor 102 without the first selective water-permeable membrane layer 13 can contact the gas to be measured and the water molecules in the air at the same time. The second sensor 102 includes a second sensing electrode 12, and the second sensing electrode 12 is connected to the outside world through the sensing surface of the second sensor 102. The electrical signal detected by the second sensing electrode 12 is a superimposed electrical signal caused by both the gas molecules to be measured and the water molecules, and the superimposed electrical signal is transmitted to the processing device 20, thereby providing data support for monitoring the concentration of the gas to be measured.

[0057] In other embodiments, the surface of the sensing electrode inside the first sensor 101 may be covered with the first selective water permeable membrane layer 13, such as Figure 3As shown, the sensing device 10 includes a first sensor 101 and a second sensor 102. The first sensor 101 includes a first sensing electrode 11, and a first selective water-permeable membrane layer 13 is provided on the surface of the first sensing electrode 11. For example, a membrane layer that only allows water molecules to pass is coated on the surface of the first sensing electrode 11, so that the first sensing electrode 11 can contact with water molecules but basically not contact with gas molecules to be measured, so as to generate an electrical signal caused by humidity changes. The first sensing electrode 11 transmits the humidity electrical signal to the processing device 20, thereby providing data support for monitoring the concentration of the gas to be measured. In addition, the second sensor 102 without a selective water-permeable membrane layer can contact the gas to be measured and water molecules in the air at the same time. The second sensor 102 includes a second sensing electrode 12, and the second sensing electrode 12 is connected to the outside world through the sensing surface of the second sensor 102. The electrical signal generated by the second sensing electrode 12 is a superimposed electrical signal caused by both the gas molecules to be measured and the water molecules, and the superimposed electrical signal is transmitted to the processing device 20, thereby providing data support for monitoring the concentration of the gas to be measured.

[0058] For example, a selective water-permeable membrane layer is coated on the surface of the sensing electrode inside the electrochemical sensor. For example, the electrode is immersed in an emulsion of Nafion material and then lifted up. After the solvent dries, the electrode surface is naturally covered with a layer of Nafion polymer membrane layer. The thickness of the membrane layer can be between several microns and several hundred microns. It is sufficient that the membrane layer does not affect the speed at which water molecules penetrate and contact the electrode, and at the same time can prevent the gas to be measured from penetrating and contacting the electrode.

[0059] In other embodiments of the present invention, the electrode coated with the selective water-permeable membrane layer can be integrated into the sensor and arranged as a single electrode, so that the structure is simplified. This electrode is in the same environment as the normal sensing electrode without the water-permeable membrane layer inside the sensor, so the responses of the two to humidity changes are nearly consistent. Specifically, the sensing device 10 of the embodiment of the present invention includes a sensor, which includes a first sensing electrode 11 and a second sensing electrode 12, wherein the first selective water-permeable membrane layer 13 is arranged on the surface of the first sensing electrode 11, for example, the first selective water-permeable membrane layer 13 is coated on the surface of the first sensing electrode 11 in the manner described above; or, the first selective water-permeable membrane layer 13 is arranged on the sensing surface of the sensor and only covers the part of the first sensing electrode 11 connected to the outside world, so that the first sensing electrode 11 can contact with water molecules but not with the gas molecules to be measured, so as to generate a humidity electrical signal caused by humidity changes; the second sensing electrode 12 is used to contact with water molecules and gas molecules to be measured to generate a superimposed electrical signal caused by water molecules and gas molecules to be measured. The humidity electrical signal and the superimposed electrical signal are transmitted to the processing device 20, thereby providing data support for monitoring the concentration of the gas to be measured.

[0060] In the above embodiment, it is equivalent to replacing the first sensor 101 with the first selective water-permeable membrane layer 13 on the sensing surface with the first sensing electrode 11 coated with a selective water-permeable membrane material or provided with the first selective water-permeable membrane layer 13 on the sensing surface part in contact with the air. The coated first sensing electrode 11 can share the auxiliary electrode and the reference electrode with the normal sensing electrode, i.e., the second sensing electrode 12, inside the same sensor, thereby further simplifying the configuration, i.e., only one sensor is needed to achieve the humidity deduction instead of two sensors.

[0061] In an embodiment, each sensor may include at least one auxiliary electrode or reference electrode, for example, may include one or two auxiliary electrodes, or one or two reference electrodes, and may be implemented in any one or more of a variety of combinations as required.

[0062] For example, in Example 1, the sensor device 10 includes two sensors, both of which include a sensing electrode, a counter electrode and a reference electrode, and a selective water permeable membrane layer 13 is arranged on the sensing surface of one of the sensors or the surface of the sensing electrode is covered with the selective water permeable membrane layer; in Example 2, the sensor device 10 includes two sensors, both of which include a sensing electrode, an auxiliary electrode, a counter electrode and a reference electrode, and a selective water permeable membrane layer 13 is arranged on the sensing surface of one of the sensors or the surface of the sensing electrode is covered with the selective water permeable membrane layer; in Example 4, the sensor device 10 includes a sensor, which includes two sensing electrodes, an auxiliary electrode, two counter electrodes and a reference electrode, and the surface of one of the sensing electrodes is covered with the first selective water permeable membrane layer 13. In short, the sensor device 10 can be implemented in a variety of combinations, and the above are only examples of the combinations given. Other combinations are also within the structural scope of the sensor device 10 of the present application, and are not listed here one by one.

[0063] In some embodiments, for a sensor device 10 that does not include an auxiliary electrode, such as the sensor device 10 in the above-mentioned embodiment 1, the processing device 20 can obtain the concentration of the gas to be measured according to the following formula:

[0064]

[0065] Alternatively, in some embodiments, for the sensing device 10 including an auxiliary electrode, for example Figure 4 As shown, the sensing device 10 includes a first sensor 101 and a second sensor 102, the first sensor 101 includes a first sensing electrode 11, a first auxiliary electrode 15, and a first selective water-permeable membrane layer 13, and the second sensor 102 includes a second sensing electrode 12 and a second auxiliary electrode 16, then the processing device 20 can obtain the concentration of the gas to be measured according to the following formula:

[0066]

[0067] In the above two equations, [P](t) is the concentration of the gas to be measured at different times t, W 2 (t) is the detection electrical signal of the second sensing electrode, W 1 (t) is the detection signal of the second auxiliary electrode, A 2 (t) is the detection signal of the first sensing electrode, A 1 (t) is the detection signal of the first auxiliary electrode, and a, b, c and s are empirical coefficients that can be obtained through calibration experiments.

[0068] The above are just two examples of calculating the concentration of the gas to be measured. Specifically, the formula can be transformed according to the detection of the specific environment or parameters. The changed formula obtained by transforming the above formula also falls within the protection scope of this application.

[0069] Furthermore, one of the core steps of using the gas sensor is to determine the relevant constants such as a, b, c and s in the above formula by an appropriate method. This process is usually called the calibration process of the sensor. During the calibration, the sensor device 10 can be placed in the gas environment to be measured, which is generally an outdoor environment where the temperature, humidity and concentration of the gas to be measured are constantly changing, but can also be other environments such as a laboratory environment where the temperature and humidity can be controlled.

[0070] by Figure 4 As an example, the sensor device 10 shown in FIG. 1 is used, wherein the superimposed electrical signal generated by the second sensor electrode 12 is set to W 2 (t), the electrical signal generated by the second auxiliary electrode 16 is set to W 1 (t). Correspondingly, the humidity electrical signal generated by the first sensing electrode 11 is set to A 2 (t), the electrical signal generated by the first auxiliary electrode 15 is set to A 1 (t). For sensors with a common auxiliary electrode, W 1 (t) = A 1(t). At the same time, it is assumed that the concentration of the gas to be measured in the gas environment to which the sensor is exposed is [P](t). This concentration can be measured by a standard instrument (including but not limited to outdoor environment), or can be calculated based on the standard gas concentration in a laboratory environment or based on specific gas distribution conditions, and is not specifically limited here. In an embodiment, multivariate linear regression can be carried out by the above formula (2), wherein a, b, and c are parameters to be determined, which roughly correspond to the temperature compensation term coefficient, the humidity compensation term coefficient, and the sensor baseline compensation coefficient, respectively. Among them, a and b have no units, and the unit of c is consistent with the output voltage unit obtained after the output current of the sensor is converted by IV, which is generally mV (millivolt). s is the concentration response coefficient of the sensor to the gas P to be measured, and its unit is generally mV / ppb (part per billion, gas mixture concentration unit), or other units, depending on the output voltage unit of the sensor and the specific gas concentration unit selected.

[0071] The specific duration of the calibration process, the calibration environment, the selected temperature and humidity variation range, etc. can be determined by an experienced sensor user and are not specifically limited here. As long as the experimental data and information obtained during the calibration period are helpful to accurately determine the parameters to be determined in formula (2), it is sufficient. Further, in the above formula (2), the concentration response coefficient s can be set as a function of temperature, that is, the sensitivity of the sensor changes with temperature changes, but this depends on the temperature and humidity variation range and variation rate during the calibration period, the gas concentration variation range and the accuracy of the standard instrument data. When the experimental data does not allow further determination of the temperature dependence of s, it can be assumed that s is a constant and does not change with temperature. In other words, sometimes the amount of information contained in the experimental data is not enough to accurately determine the dependence of s on temperature. Similarly, a, b, and c may have a certain functional relationship with temperature, humidity, and air pressure, but whether the above functional relationship can be accurately extracted depends on whether the amount of information contained in the data during the calibration period is sufficient. Therefore, in an embodiment of the present invention, the user can intervene in the optimization process and select different parameterization schemes of a, b, c, and s according to specific environmental characteristics.

[0072] The above formula (2) can also be further simplified, especially when the calibration data does not allow accurate determination of values ​​such as a or b. Generally speaking, electrochemical sensor manufacturers try to make the sensing and auxiliary electrodes as close to the same as possible, which means that a or b can often be fixed to 1 without significantly reducing the calibration quality.

[0073] In summary, the core of the calibration algorithm is multivariate linear regression, which mainly includes the approximate temperature compensation term a×W 1 (t), approximate humidity compensation term b×(A 2 (t)-A 1 (t)) and the baseline compensation term c.

[0074] After calibration, each coefficient is a known value, and then the processing device 20 can deduct the temperature and humidity and the baseline drift according to the obtained electrical signal of the first sensing electrode 11, the electrical signal of the second sensing electrode 12 and the detection signal of the auxiliary electrode. For example, the electrical signal drift caused by the temperature and humidity change can be corrected by the above formula (2) to obtain the concentration of the gas to be measured, thereby improving the accuracy of the calculation result. The algorithm is simple.

[0075] Another method for determining parameters such as a, b, c and s is introduced below. In this calibration method, the first sensor 101 with a selective water permeable membrane layer or the first sensing electrode 11 coated with a selective water permeable membrane material remains in the film-attached or coated state, but the second sensor 102 or the second sensing electrode 12 that is not originally sealed with the selective water permeable membrane layer or the material can add or remove the membrane manually or electrically, and the adding method needs to ensure good sealing, that is, to ensure that the gas molecules to be measured cannot contact the surface of the second sensing electrode.

[0076] The first and second sensors are placed in the above-mentioned outdoor environment or in a laboratory environment where the temperature and humidity can be controlled. When the second sensor 102 or the second sensing electrode 12 is sealed and covered by the film, W at different times is continuously recorded. 1 (t), W 2 (t), A 1 (t)…etc. The recording duration, the selection of specific calibration environment, the temperature and humidity range, etc. can be determined by experienced users. After the experiment is completed, the following formula is used for multivariate regression:

[0077] 0=(W 2 (t)-a×W 1 (t)-b×(A 2 (t)-A 1 (t))-c); Formula (3)

[0078] The values ​​of a, b, and c can also be accurately determined.

[0079] In this method, since the second sensor or the second sensing electrode cannot contact the gas to be measured, it is theoretically impossible to measure the sensitivity coefficient s of the sensor or the sensing electrode in response to the gas to be measured by this method. In this case, when the sensor or the sensing electrode is not covered by the film, the value of s can be accurately measured by running it in parallel with the standard instrument in an outdoor environment or exposing the sensor to the gas to be measured with a known concentration in the laboratory, which is not specifically limited here.

[0080] It is understood by those skilled in the art that the above calibration method can be continuously implemented in a manual or automatic form so as to be repeated as needed at different time points and different positions of the sensor, which is not limited here. In the specific implementation process, one or more parameter values ​​of a, b, c and s that have been determined through the historical calibration process can also be selectively fixed, while only other parameters are allowed to be freely floated and optimized, which is not limited here.

[0081] Among them, by operating the second sensor 102 or the second sensing electrode 12, the user can conveniently calibrate the relevant parameters in the concentration calculation formula at the required time and place. For example, the second sensor 102 or the second sensing electrode 12 can be set in at least the following ways.

[0082] In some embodiments, for a sensor device 10 using one sensor, the first selective water-permeable membrane layer 13 can be disposed on the sensing surface of the sensor and covers the sensing surface portion where the first sensing electrode 11 is connected to the outside, and the first selective water-permeable membrane layer 13 can selectively cover or not cover the second sensing electrode 12. For example, the first selective water-permeable membrane layer 13 is in a foldable form, and when calibrating, the first selective water-permeable membrane layer 13 is unfolded, and the first selective water-permeable membrane layer 13 is arranged to cover the second sensing electrode 12, and the constants such as a, b, and c can be calibrated with reference to the above embodiments; when the first selective water-permeable membrane layer 13 is folded, the first selective water-permeable membrane layer 13 does not cover the sensing surface portion where the second sensing electrode 12 is connected to the outside, and at this time, the second sensing electrode 12 can contact and monitor the concentration of the target gas to be measured.

[0083] In other embodiments, similar to the arrangement of the first selective water-permeable membrane layer 13, the second sensor 102 or the second sensing electrode 12 can also be selectively operated so that the second sensing electrode 12 can be used to monitor the gas concentration and can enter the coefficient calibration mode as needed. Specifically, the sensing device 10 can also include a second selective water-permeable membrane layer, which can have the same characteristics and functions as the first selective water-permeable membrane layer 13, and the second selective water-permeable membrane layer can be detachably or movably arranged on the sensing surface of the second sensor 102, or the second selective water-permeable membrane layer can be detachably or movably arranged on the sensing surface portion of the second sensing electrode 12 that is connected to the outside. For example, when performing coefficient calibration, the second selective water-permeable membrane layer can be covered on the sensing surface of the second sensor 102, so that the second sensing electrode 12 can contact with water molecules but not with the gas molecules to be measured, and at this time, the electrical signals of the first sensing electrode 11, the second sensing electrode 12, etc. are synchronously recorded, and the values ​​of a, b, and c are determined based on the calibration process and formula (3) above. Thereafter, when gas concentration monitoring is required, the second selective water permeable membrane layer can be disassembled or removed, and gas concentration monitoring can be achieved by referring to the above embodiment.

[0084] As described above, for the second sensing electrode 12, by adopting a selectively permeable membrane layer that can be freely installed and removed, the user of the sensor device can conveniently calibrate the empirical coefficient when necessary, thereby minimizing the necessity of returning to the factory or requiring intervention by specific professionals.

[0085] Furthermore, the above formula (2) allows users to understand temperature and humidity drift from the perspective of real physical laws, and the resulting parameterization scheme corresponds to a clear physical explanation such as temperature compensation, humidity compensation, and baseline compensation terms, which makes the calibration process easier for sensor users to understand and the rationality of the results obtained easier to identify.

[0086] A sensor for monitoring gas concentration according to an embodiment of the present invention will be described below with reference to the accompanying drawings.

[0087] Figure 5 A block diagram of a sensor according to an embodiment of the present invention is shown in FIG. Figure 5As shown, the sensor 100 of the embodiment of the present invention includes a sensor body 14, a first sensing electrode 11 and a first selective water-permeable membrane layer 13, wherein the first sensing electrode 11 is arranged on the sensor body 14, and the first sensing electrode 11 is connected to the outside through the sensing surface; wherein the first selective water-permeable membrane layer 13 can be arranged on the sensing surface where the first sensing electrode 11 is connected to the outside and completely covers the portion where the first sensing electrode 11 is connected to the outside, so that the first sensing electrode 11 can contact with water molecules but not with gas molecules to be measured, so as to generate the characteristics of the change of the electrical signal caused by the change of humidity; or, the first selective water-permeable membrane layer 13 is arranged on the surface of the first sensing electrode 11, for example, a selective water-permeable membrane is coated on the surface of the first sensing electrode 11, so that the first sensing electrode 11 can contact with water molecules but not with gas molecules to be measured, so as to generate the characteristics of the change of the electrical signal caused by the change of humidity. The sensor 100 can be combined with a sensor without the selective water-permeable membrane layer 13 to monitor the concentration of the gas to be measured, with high accuracy.

[0088] According to the sensor 100 of the embodiment of the present invention, by providing the first selective water-permeable membrane layer 13, the electrical signal generated by humidity change can be separated to provide data support for the detection of the concentration of the gas to be measured.

[0089] In some embodiments, Figure 6 As shown, the sensor 100 also includes a second sensing electrode 12 disposed on the sensor body 14, and the second sensing electrode 12 is connected to the outside through the sensing surface. When monitoring the gas concentration, the second sensing electrode 12 is used to contact the water molecules and the gas molecules to be measured at the same time to detect the superimposed electrical signals caused by the water molecules and the gas molecules to be measured. Specifically, for the sensor 100 in which the first selective water-permeable membrane layer 13 covers the sensing surface of the first sensing electrode 11 or wraps the surface of the first sensing electrode 11, the concentration of the gas to be measured can be obtained based on the electrical signals generated by the first sensing electrode 11 and the second sensing electrode 12. The specific calculation process can refer to the description of the above embodiment.

[0090] In an embodiment of the present invention, the sensor 100 includes at least one auxiliary electrode or a reference electrode, for example, may include one or two auxiliary electrodes, one or two reference electrodes, and may be implemented in any one or more of a variety of combinations as needed, which are not listed here one by one.

[0091] In some embodiments, by operating the second sensing electrode 12, the second sensing electrode 12 can be used for gas concentration monitoring and, after proper processing, for calibration of relevant parameters in the gas concentration calculation formula. For example, the second sensor 101 or the second sensing electrode 12 can be set in at least the following ways.

[0092] In some embodiments, the first selective water-permeable membrane layer 13 may be disposed on the sensing surface of the sensor and cover the portion of the first sensing electrode 11 that is in communication with the outside world, and the first selective water-permeable membrane layer 13 may selectively cover or not cover the portion of the sensing surface of the second sensing electrode 12 that is in communication with the outside world. For example, when the first selective water-permeable membrane layer 13 is disposed not to cover the second sensing electrode 12, the gas concentration may be monitored with reference to the above embodiment; when the first selective water-permeable membrane layer 13 covers the second sensing electrode 12, the values ​​of a, b, and c may be determined by recording the electrical signal of the second sensing electrode 12 and referring to the above calibration process.

[0093] In other embodiments, similar to the configuration of the first selective water-permeable membrane layer 13, the second sensor 102 or the second sensing electrode 12 may also be selectively operated so that the user can conveniently calibrate the empirical coefficient in the gas concentration calculation formula. Figure 7 As shown in FIG. 8 , the sensor 100 may further include a second selective water-permeable membrane layer 17. The second selective water-permeable membrane layer 17 may have the same properties and functions as the first selective water-permeable membrane layer 13. The second selective water-permeable membrane layer 17 may be detachably or movably disposed on the sensing surface where the second sensing electrode 12 is connected to the outside world, so as to selectively cover or not cover the portion where the second sensing electrode 12 is connected to the outside world. For example, when the second selective water-permeable membrane layer 17 is disposed on the sensing surface of the sensor 100, it covers the portion where the second sensing electrode 12 is connected to the outside world, as shown in FIG. Figure 7 Alternatively, the second selective water-permeable membrane layer 17 is detachably or movably disposed on the surface of the second sensing electrode 12, such as Figure 8 The schematic diagram shown is a second selective water permeable membrane layer wrapped on the surface of the second sensing electrode 12. Figure 7 and Figure 8 This is only an example of the arrangement of the first selective water permeable membrane layer 13 and the second selective water permeable membrane layer 17. The two membrane layers may be arranged in other combinations, which are not specifically limited herein.

[0094] For example, when performing coefficient calibration, the second selective water-permeable membrane layer 17 can be closely attached to the sensing surface of the second sensor 102 and cover the part of the second sensing electrode 12 connected to the outside world. The second sensing electrode 12 can contact with water molecules but not with the gas molecules to be measured. The response signal of the second sensing electrode 12 to temperature and humidity and its baseline signal are recorded, and the values ​​of a, b, and c are determined based on the calibration process described above. Alternatively, when performing gas concentration monitoring, the second selective water-permeable membrane layer 17 is removed, and gas concentration monitoring is achieved by referring to the above embodiment.

[0095] As described above, for the second sensing electrode 12, by adopting a selective water-permeable membrane layer that can be freely installed and removed, it is convenient to realize repeated calibration of the empirical coefficient when needed, without returning to the factory or requiring intervention by specific professionals, which is time-saving and convenient.

[0096] Based on the devices and sensors of the above embodiments, the embodiments of the present invention further provide a method for monitoring gas concentration. Fig. 9 is a flow chart of a method for monitoring gas concentration according to an embodiment of the present invention. Fig. 9 As shown, the method at least includes step S1 and step S2.

[0097] Step S1, obtaining an electrical signal generated by humidity change and a superimposed electrical signal caused by humidity change and gas molecules to be detected.

[0098] The configuration of the sensor device and the configuration of each electrode may refer to the description of the above embodiment.

[0099] Step S2, obtaining the concentration of the gas to be measured according to the electrical signal generated by the humidity change and the superimposed electrical signal.

[0100] Specifically, the concentration of the gas to be measured can be obtained according to the formula (1) given above, wherein the calibration of each parameter can refer to the description of the above embodiment.

[0101] Alternatively, for a sensor device including an auxiliary electrode, the concentration of the gas to be measured can be obtained according to the formula (2) given above. The detection signal of the second auxiliary electrode can be used as a temperature-related term, and the humidity electrical signal and the detection signal of the first auxiliary electrode can be used as humidity-related terms, so that the processing device can obtain the electrical signal associated with the gas molecules to be measured by deducting the temperature-related term and the humidity-related term from the superimposed electrical signal caused by the water molecules and the gas molecules to be measured, thereby determining the concentration of the gas to be measured.

[0102] According to the method for monitoring gas concentration of an embodiment of the present invention, based on a selective water-permeable membrane layer, a first sensing electrode and a second sensing electrode, the humidity electrical signal caused by water molecules is separated, and then the temperature-related term and the humidity-related term are deducted from the superimposed electrical signal caused by the water molecules and the gas molecules to be measured to obtain the electrical signal associated with the gas molecules to be measured. The method can quickly and effectively perform environmental temperature and humidity correction, accurately determine the concentration of the gas to be measured, and has high versatility.

[0103] It should be noted that any sensor that responds to changes in temperature and humidity, such as electrochemical sensors or other equivalent sensors, can accurately measure the humidity response signal of the sensor used through the above design concept, that is, by setting a selective water-permeable membrane layer on the sensor surface or wrapping or coating the surface of the sensing material with a membrane layer, and further perform mathematical analysis, baseline subtraction, etc. to correct the sensor baseline drift caused by humidity.

[0104] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example.

[0105] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A device for monitoring gas concentration, characterized in that: include: An electrochemical sensing device comprising a first selectively water-permeable membrane layer, a first sensing electrode, and a second sensing electrode, wherein the first selectively water-permeable membrane layer is configured to allow the first sensing electrode to contact water molecules but not contact gas molecules to be detected, the first sensing electrode is configured to generate an electrical signal caused by a change in humidity, and the second sensing electrode is configured to generate a superimposed electrical signal caused by a reaction between the change in humidity and the gas molecules to be detected; a processing device for obtaining the concentration of the gas to be measured based on the electrical signal caused by the humidity change and the superimposed electrical signal; The concentration of the gas to be measured is obtained according to the following formula: Alternatively, the electrochemical sensing device includes a first sensor and a second sensor, the first sensor includes the first sensing electrode and a first auxiliary electrode, and the second sensor includes the second sensing electrode and a second auxiliary electrode, and the concentration of the gas to be measured is obtained according to the following formula: ; Among them, [P]( t ) is the concentration of the gas to be measured, W 2( t ) is the detection signal of the second sensing electrode, W 1( t ) is the detection signal of the second auxiliary electrode, A 2( t ) is the detection signal of the first sensing electrode, A 1( t ) is the detection signal of the first auxiliary electrode, t is time, a is the temperature compensation term coefficient, b is the humidity compensation term coefficient, c is the baseline compensation coefficient of the electrochemical sensor device, and s is the concentration response coefficient of the electrochemical sensor device to the gas to be measured.

2. The device for monitoring gas concentration according to claim 1, characterized in that: The electrochemical sensing device includes a first sensor and a second sensor, the first sensor includes the first sensing electrode, the second sensor includes the second sensing electrode, the first sensing electrode is connected to the outside world through the sensing surface of the first sensor, and the second sensing electrode is connected to the outside world through the sensing surface of the second sensor; Wherein, the first selective water-permeable membrane layer is arranged on the sensing surface of the first sensor, or the first selective water-permeable membrane layer is arranged on the surface of the first sensing electrode.

3. The device for monitoring gas concentration according to claim 2, characterized in that: The electrochemical sensing device further comprises: a second selectively water-permeable membrane layer, wherein the second selectively water-permeable membrane layer is used not to cover the sensing surface of the second sensor or the portion of the sensing surface of the second sensing electrode connected to the outside world when monitoring gas concentration, and, during coefficient calibration, to cover the sensing surface of the second sensor or the portion of the sensing surface of the second sensing electrode connected to the outside world.

4. The device for monitoring gas concentration according to claim 1, characterized in that: The electrochemical sensing device comprises: A sensor, wherein the sensor comprises the first sensing electrode and the second sensing electrode, wherein the first sensing electrode and the second sensing electrode are connected to the outside world through a sensing surface of the sensor, wherein the first selective water-permeable membrane layer is provided on a surface of the first sensing electrode, or the first selective water-permeable membrane layer is provided on a portion of the sensing surface of the first sensing electrode that is connected to the outside world; The first selective water-permeable membrane layer is configured to selectively cover or not cover the second sensing electrode. When monitoring gas concentration, it does not cover the sensing surface portion of the second sensing electrode that is connected to the outside world. When calibrating the coefficient, it covers the sensing surface portion of the second sensing electrode that is connected to the outside world.

5. The device for monitoring gas concentration according to claim 4, characterized in that: The electrochemical sensing device further comprises: A second selectively water-permeable membrane layer is detachably or movably arranged to selectively cover or not cover the second sensing electrode, and does not cover the sensing surface portion of the second sensing electrode of one of the sensors that is connected to the outside world when monitoring gas concentration; and covers the sensing surface portion of the second sensing electrode that is connected to the outside world when calibrating the coefficient.

6. An electrochemical sensor for monitoring gas concentration, characterized in that: The electrochemical sensor comprises: sensor body; a first sensing electrode and a first selective water-permeable membrane layer, wherein the first sensing electrode is disposed on the sensor body and is connected to the outside world through the sensing surface; The first selective water-permeable membrane layer is provided on the sensing surface of the first sensing electrode that is in communication with the outside world and completely covers the sensing surface, so that the first sensing electrode can come into contact with water molecules but not with gas molecules to be measured, thereby generating an electrical signal variation characteristic caused by humidity change; Alternatively, the first selective water-permeable membrane layer is disposed on the surface of the first sensing electrode so that the first sensing electrode can contact water molecules but not contact gas molecules to be measured, thereby generating an electrical signal change characteristic caused by humidity change; The electrochemical sensor further comprises a second sensing electrode disposed on the sensor body, wherein the second sensing electrode is connected to the outside world through the sensing surface; The concentration of the gas to be measured is obtained according to the following formula: Alternatively, the concentration of the gas to be measured is obtained based on two electrochemical sensors, where the two electrochemical sensors are a first sensor and a second sensor, the first sensor includes the first sensing electrode and a first auxiliary electrode, and the second sensor includes the second sensing electrode and a second auxiliary electrode, and the concentration of the gas to be measured is obtained according to the following formula: ; Among them, [P]( t ) is the concentration of the gas to be measured, W 2( t ) is the detection signal of the second sensing electrode, W 1( t ) is the detection signal of the second auxiliary electrode, A 2( t ) is the detection signal of the first sensing electrode, A 1( t ) is the detection signal of the first auxiliary electrode, t is time, a is the temperature compensation term coefficient, b is the humidity compensation term coefficient, c is the baseline compensation coefficient of the electrochemical sensor device, and s is the concentration response coefficient of the electrochemical sensor device to the gas to be measured.

7. The electrochemical sensor for monitoring gas concentration according to claim 6, characterized in that: The first selective water-permeable membrane layer is also used for not covering the sensing surface portion of the second sensing electrode connected to the outside when monitoring gas concentration, and for covering the sensing surface portion of the second sensing electrode connected to the outside when calibrating coefficients.

8. The electrochemical sensor for monitoring gas concentration according to claim 6, characterized in that: The sensor also includes a second selectively water-permeable membrane layer, which is used to not cover the sensing surface of the second sensing electrode connected to the outside world or the surface of the second sensing electrode when monitoring gas concentration, and to cover the sensing surface of the second sensing electrode connected to the outside world or the surface of the second sensing electrode when calibrating the coefficient.

9. A method for monitoring gas concentration, characterized in that: For the device for monitoring gas concentration according to claim 1, the method comprises: Obtaining the electrical signal generated by humidity change and the superimposed electrical signal caused by humidity change and the gas molecules to be measured; Obtaining the concentration of the gas to be measured according to the electrical signal and the superimposed electrical signal; The concentration of the gas to be measured is obtained according to the following formula: Alternatively, the sensing device includes a first sensor and a second sensor, the first sensor includes the first sensing electrode and a first auxiliary electrode, and the second sensor includes the second sensing electrode and a second auxiliary electrode, and the concentration of the gas to be measured is obtained according to the following formula: ; Among them, [P]( t ) is the concentration of the gas to be measured, W 2( t ) is the detection signal of the second sensing electrode, W 1( t ) is the detection signal of the second auxiliary electrode, A 2( t ) is the detection signal of the first sensing electrode, A 1( t ) is the detection signal of the first auxiliary electrode, t is time, a is the temperature compensation coefficient, b is the humidity compensation coefficient, c is the baseline compensation coefficient of the electrochemical sensor device, and s is the concentration response coefficient of the electrochemical sensor device to the gas to be measured.

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