Method of prolonging the service life and reducing noise signals, sensor and testing device

Abstract

The application belongs to the technical field of oxygen sensors. A method for prolonging service life and reducing noise signals, a sensor and a testing device are provided. According to a first closed current signal of a first electrode, a first closed current signal of a second electrode, a first testing current signal of the first electrode and a first testing current signal of the second electrode, a real signal generated by oxygen molecule reaction of the first electrode is determined, noise signals caused by derived current are shielded to a higher degree, and the measurement accuracy of the sensor is greatly improved. When the current signal attenuation of the first electrode is greater than a set threshold, the second electrode is enabled, and the service life is prolonged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oxygen sensor, in particular to a method for prolonging service life and reducing noise signal, a sensor and a testing device. BACKGROUND

[0002] The statements in this section merely provide background information related to the present application and do not necessarily constitute the prior art.

[0003] The electrochemical oxygen sensor detects the oxygen concentration by the reaction of oxygen molecules entering the sensor and active substances in the sensor to generate current, one oxygen molecule generates four electrons, and the oxygen content of the measured gas can be derived by measuring the output current of the sensor. However, the current electrochemical oxygen sensor has the following problems:

[0004] (1) As the oxygen molecules and active substances continue to react, the active substances will be gradually consumed, at this time the output signal of the sensor will be greatly attenuated, and the sensor can no longer be used; (2) The current output by the sensor includes not only the current generated by the reaction of oxygen molecules, but also some derivative currents generated by non-oxygen molecules, which are noise signals for the current generated by oxygen molecules, seriously affecting the accuracy of the sensor. SUMMARY

[0005] In order to solve the problems of the prior art, the present application provides a method for prolonging service life and reducing noise signal, a sensor and a testing device, which has a high shielding effect on the noise signal caused by the derivative current, greatly improving the measurement accuracy of the sensor.

[0006] In order to achieve the above purpose, the present application adopts the following technical scheme:

[0007] In the first aspect, the present application provides a method for prolonging service life and reducing noise signal.

[0008] A method for prolonging service life and reducing noise signal, using a first electrode and a second electrode installed in the same sensor shell, comprising the following processes:

[0009] The first electrode and the second electrode are separately closed to obtain a first closed current signal of the first electrode and a first closed current signal of the second electrode;

[0010] The first electrode is introduced into the test gas, and the second electrode is kept closed to obtain a first test current signal of the first electrode and a first test current signal of the second electrode;

[0011] The real signal of the oxygen molecule reaction of the first electrode is determined according to the first closed current signal of the first electrode, the first closed current signal of the second electrode, the first test current signal of the first electrode and the first test current signal of the second electrode.

[0012] In an implementation form of the first aspect of the application, the real signal of the oxygen molecule reaction of the first electrode is:

[0013] A = A' - B0n1 - (A01 - B01);

[0014] Wherein, A' is the first test current signal of the first electrode, B0n1 is the first test current signal of the second electrode, A01 is the first closed current signal of the first electrode, B01 is the first closed current signal of the second electrode, and A is the real signal of the oxygen molecule reaction of the first electrode.

[0015] In an implementation form of the first aspect of the application, the first closed current signal of the first electrode and the first closed current signal of the second electrode change synchronously with temperature.

[0016] In an implementation form of the first aspect of the application, when the current signal attenuation of the first electrode is greater than a set threshold, the first electrode and the second electrode are respectively closed alone to obtain the second closed current signal of the first electrode and the second closed current signal of the second electrode.

[0017] Then the second electrode is introduced into the test gas, and the first electrode remains closed to obtain the second test current signal of the second electrode and the second test current signal of the first electrode.

[0018] The real signal of the oxygen molecule reaction of the second electrode is determined according to the second closed current signal of the first electrode, the second closed current signal of the second electrode, the second test current signal of the second electrode and the second test current signal of the first electrode.

[0019] As a further limitation, the real signal of the oxygen molecule reaction of the second electrode is:

[0020] B = B' - A0n2 - (B02 - A02);

[0021] Wherein, B' is the second test current signal of the second electrode, A0n2 is the second test current signal of the first electrode, A02 is the second closed current signal of the first electrode, B02 is the second closed current signal of the second electrode, and B is the real signal of the oxygen molecule reaction of the second electrode.

[0022] As a further limitation, the second closed current signal of the first electrode and the second closed current signal of the second electrode change synchronously with temperature.

[0023] In a second aspect, the present application provides an electrochemical oxygen sensor.

[0024] An electrochemical oxygen sensor comprises: a first electrode and a second electrode installed in a same sensor housing;

[0025] The first electrode and the second electrode are arranged in isolation from each other in the sensor housing, the first electrode is arranged in a first space, and the second electrode is arranged in a second space;

[0026] The first space is provided with a first gas inlet and a first gas outlet, and the second space is provided with a second gas inlet and a second gas outlet, the first gas inlet, the second gas inlet, the first gas outlet and the second gas outlet are respectively arranged with corresponding plugs;

[0027] The first electrode is connected with a first electrode lead, and the second electrode is connected with a second electrode lead;

[0028] The first electrode and the second electrode are respectively individually closed to obtain a first closed current signal of the first electrode and a first closed current signal of the second electrode;

[0029] The first electrode is supplied with a test gas, and the second electrode is kept closed to obtain a first test current signal of the first electrode and a first test current signal of the second electrode;

[0030] The first closed current signal of the first electrode, the first closed current signal of the second electrode, the first test current signal of the first electrode and the first test current signal of the second electrode are used to determine a real signal generated by an oxygen molecule reaction of the first electrode.

[0031] In an implementation form of the second aspect of the present application, when the current signal attenuation of the first electrode is greater than a set threshold, the first electrode and the second electrode are respectively individually closed to obtain a second closed current signal of the first electrode and a second closed current signal of the second electrode;

[0032] Then the second electrode is supplied with a test gas, and the first electrode is kept closed to obtain a second test current signal of the second electrode and a second test current signal of the first electrode;

[0033] The second closed current signal of the first electrode, the second closed current signal of the second electrode, the second test current signal of the second electrode and the second test current signal of the first electrode are used to determine a real signal generated by an oxygen molecule reaction of the second electrode.

[0034] As a further limitation, the first closed current signal of the first electrode and the first closed current signal of the second electrode change synchronously with temperature; the second closed current signal of the first electrode and the second closed current signal of the second electrode change synchronously with temperature.

[0035] In a third aspect, the present application provides an oxygen permeability testing device, comprising the electrochemical oxygen sensor of the second aspect of the present application.

[0036] Compared with the prior art, the present application has the following beneficial effects:

[0037] 1、The present application innovatively provides a method for prolonging the service life and reducing noise signals, according to the first closed current signal of the first electrode, the first closed current signal of the second electrode, the first test current signal of the first electrode and the first test current signal of the second electrode, the real signal generated by the oxygen molecule reaction of the first electrode is determined, the noise signal caused by the derived current is shielded to a higher degree, and the measurement accuracy of the sensor is greatly improved.

[0038] 2、The present application innovatively provides a method for prolonging the service life and reducing noise signals, when the current signal attenuation of the first electrode is greater than the set threshold value (i.e. the first electrode attenuates and cannot be used), according to the second closed current signal of the first electrode, the second closed current signal of the second electrode, the second test current signal of the second electrode and the second test current signal of the first electrode, the real signal generated by the oxygen molecule reaction of the second electrode is determined, the two electrodes cooperate, the service life is doubled under the premise of ensuring the measurement accuracy of the sensor.

[0039] The advantages of the additional aspects of the present application will be partially given in the following description, partially will become obvious from the following description, or will be known by the practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0040] The drawings accompanying the specification of the present application form a part thereof, serve to provide further understanding of the present application, and together with the description of the exemplary embodiments of the present application and their description serve to explain the present application, and do not constitute improper limitations on the present application.

[0041] Figure 1 The schematic diagram of the electrochemical oxygen sensor provided for an exemplary embodiment of the present application Figure One ;

[0042] Figure 2 The schematic diagram of the electrochemical oxygen sensor provided for an exemplary embodiment of the present application Figure Two ;

[0043] Figure 3 The schematic diagram of the method for prolonging the service life and reducing noise signals provided for an exemplary embodiment of the present application Figure One ;

[0044] Figure 4 The schematic diagram of the method for prolonging the service life and reducing noise signals provided for an exemplary embodiment of the present application Figure Two ;

[0045] Wherein, 1, first electrode; 2, first electrode lead; 3, sensor shell; 4-1, first air inlet; 4-2, first air outlet; 5-1, first air inlet plug; 5-2, first air outlet plug; 6, second electrode lead; 7, second electrode; 8-1, second air inlet plug; 8-2, second air outlet plug; 9-1, second air inlet; 9-2, second air outlet. DETAILED DESCRIPTION

[0046] The application will be further described below in conjunction with the accompanying drawings and examples.

[0047] It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the application. Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0048] The present implementation proposes an electrochemical oxygen sensor, as shown in Figure 1 and Figure 2 comprising: a first electrode 1 and a second electrode 7 installed in the same sensor shell 3;

[0049] The first electrode 1 and the second electrode 7 are arranged in isolation from each other in the sensor shell 3, the first electrode 1 is arranged in a first space, and the second electrode 7 is arranged in a second space;

[0050] The first space is provided with a first air inlet 4-1 and a first air outlet 4-2, and the second space is provided with a second air inlet 9-1 and a second air outlet 9-2, the first air inlet 4-1, the second air inlet 9-1, the first air outlet 4-2 and the second air outlet 9-2 are respectively arranged with corresponding plugs (first air inlet plug 5-1, second air inlet plug 8-1, first air outlet plug 5-2 and second air outlet plug 8-2 respectively), the first electrode 1 is connected with the first electrode lead 2, and the second electrode 7 is connected with the second electrode lead 6.

[0051] Based on the above-mentioned electrochemical oxygen sensor, the present application proposes a method for prolonging the service life and reducing the noise signal, specifically, when the first electrode 1 is used for testing, as shown in Figure 3 comprising the following processes:

[0052] S101: First, two groups of electrodes are separately closed, at this time the output current signals of the first electrode 1 and the second electrode 7 are measured, respectively obtaining the first closed current signal A01 of the first electrode 1 and the first closed current signal B01 of the second electrode 7, because there is no gas input, the signal obtained at this time is the noise signal generated by the electrode derived reaction, the difference between the two is Δ0, that is: .

[0053] S102: The first electrode 1 is connected to the test gas, and the second electrode 7 is still closed. At this time, the first test current signal of the first electrode 1 is A' (essentially A+A0n1), A is the true signal generated by the oxygen molecule reaction (i.e. the true signal essentially desired by the present application), A0n1 is the noise signal generated by the derivative reaction, and the first test current signal of the second electrode 7 is B0n1;

[0054] The current signals A0n1 and B0n1 generated by the derivative reaction are determined by impurities in the electrode material and the manufacturing process. Once a set of electrodes is made, the derivative current as its inherent characteristic is also formed, which only changes with the ambient temperature. The materials and processes of the first electrode 1 and the second electrode 7 are completely consistent, and they are in the same temperature space, so the difference between A0n1 and B0n1 is not large. The two sets of electrodes fluctuate synchronously with temperature, and there is a small difference Δ0n, that is: Δ0n=A0n1-B0n1.

[0055] S103: The signals of the two electrodes are processed, and the signal A output by the oxygen molecule reaction of the first electrode 1 is obtained:

[0056] A=A'-B0n1-△0=A'-B0n1-(A01-B01) (1);

[0057] The proof process is as follows:

[0058] As described in S102, the first test current signal A' is measured when the first electrode 1 is connected to the gas. The second electrode 7 is closed when the first electrode 1 is connected to the gas, but is affected by various factors, and the output current of the second electrode 7 is no longer B01, but B0n1. At this time, if the first electrode 1 is closed, its output current should be A0n1, but A0n1 cannot be measured at this time, so A0n1 needs to be calculated and derived first. Because the closed currents of the first electrode 1 and the second electrode 7 are noise signals, and are inherent to the electrodes, regardless of how the noise signal changes with environmental factors, the difference is fixed and unchanged, so we can get:

[0059] A01-B01=A0n1-B0n1 (2);

[0060] According to equation (2), we can get:

[0061] A0n1=A01-B01+B0n1 (3);

[0062] Then:

[0063] (4);

[0064] The true signal generated by the oxygen molecule reaction of the first electrode 1 can be obtained by the above method The test results are shown in Table 1.

[0065] Table 1: Test results of the first electrode

[0066]

[0067] It can be seen that, by using the above method, the noise signal caused by the derived current is almost completely shielded, and the measurement accuracy of the sensor is improved. The traditional calculation method of the true current signal generated by the oxygen molecule reaction is A = A' - A01, and the value obtained according to the data in Table 1 is A = 6.1783 - 1.5518 = 4.6265, which is 12% larger than the A value calculated by the method of the present application in Table 1. This is mainly because the noise signal of the first electrode is a variable value during the test, and using a fixed closed current signal A01 as the noise signal will have deviation.

[0068] When the signal of the first electrode 1 decays to the extent that it cannot be used (for example, the decay amount of the signal of the first electrode 1 is greater than a set threshold value, which is limited according to specific circumstances and will not be described here), the second electrode 7 is started to be used, as shown in Figure 4 The specific process includes:

[0069] S201: First, close the two electrodes to obtain the static derived current signals A02 (i.e. the second closed current signal of the first electrode 1) and B02 (i.e. the second closed current signal of the second electrode 7) at this time. At this time, the signals obtained are noise signals generated by electrode derived reactions, and the difference between the two is Δ1, i.e. Δ1 = B02 - A02. The calculation method of Δ1 is derived from the final derivation result of formula (8) below. The final derivation is to subtract "B02 - A02", i.e. subtract Δ1, so Δ1 is set as the difference between B02 and A02.

[0070] S202: The second electrode 7 is connected to the test gas, and the first electrode 1 remains closed. At this time, the second test current signal of the second electrode 7 is B' (i.e. B + B0n2), B is the signal generated by the oxygen molecule reaction of the second electrode 7, B0n2 is the noise signal generated by the derived reaction, and the second test current signal of the first electrode is A0n2.

[0071] S203: The signals of the two groups of electrodes are operated and processed to obtain the signal B output by the oxygen molecule reaction of the second electrode 7:

[0072] B = B' - A0n2 - Δ1 = B' - A0n2 - (B02 - A02) (5);

[0073] The proof process is as follows:

[0074] As described in S202, the second test current signal B' is measured when the second electrode 7 is ventilated, the first electrode 1 is closed when the second electrode 7 is ventilated, but the output current of the first electrode 1 is no longer A02, but A0n2, at this time, if the second electrode 7 is closed, the output current should be B0n2, but at this time, B0n2 cannot be measured, so B0n2 needs to be derived here. Because the closed current of the first electrode 1 and the second electrode 7 are both noise signals, and are inherent to each electrode, regardless of how the noise signal changes with environmental factors, the difference is fixed, so it can be obtained that:

[0075] A02-B02=A0n2-B0n2(6);

[0076] According to formula (6), it can be obtained that:

[0077] B0n2=A0n2+B02-A02(7);

[0078] Then:

[0079] (8);

[0080] The final real signal B of the oxygen molecule reaction of the second electrode 7 can be obtained by the above-mentioned manner, and the test results are shown in Table 2.

[0081] Table 2: Test results of the second electrode

[0082]

[0083] The traditional calculation method for calculating the real current signal of the oxygen molecule reaction is B=B'-B02, and the value obtained according to the data in Table 2 is B=17.6806-0.8872=16.7934, which is 2.1% larger than the B value calculated by the method of the patent in Table 2. Because the noise signal of the second electrode is a variable value during the test, using a fixed closed current signal B02 as the noise signal will have deviation.

[0084] As can be seen from the above, by the above-mentioned method, one sensor of the present application is configured with the first electrode 1 and the second electrode 7, the second electrode 7 is enabled after the attenuation of the first electrode 1, so that the service life of the sensor is doubled.

[0085] The present application also provides an oxygen permeability test device, which comprises the above-mentioned electrochemical oxygen sensor, and the specific oxygen permeability test device adopts the existing method, only the electrochemical oxygen sensor therein is replaced by the form of the present application, and details are not described herein.

[0086] The above merely provides the preferred embodiments of the present application, and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the principles and technical scope of the present application shall fall into the scope of the present application.

Claims

1. A method for extending service life and reducing noise signals, characterized in that, Using a first electrode and a second electrode mounted within the same sensor housing, the following process is included: The first electrode and the second electrode are sealed separately to obtain the first sealing current signal of the first electrode and the first sealing current signal of the second electrode. The test gas is introduced into the first electrode, and the second electrode is kept closed, so that the first test current signal of the first electrode and the first test current signal of the second electrode are obtained. Based on the first closed current signal of the first electrode, the first closed current signal of the second electrode, the first test current signal of the first electrode, and the first test current signal of the second electrode, the actual signal generated by the oxygen molecule reaction of the first electrode is determined. When the attenuation of the current signal of the first electrode is greater than the set threshold, the first electrode and the second electrode are individually closed to obtain the second closed current signal of the first electrode and the second closed current signal of the second electrode. Then, the test gas is introduced into the second electrode while the first electrode remains closed, and the second test current signal of the second electrode and the second test current signal of the first electrode are obtained. Based on the second closed current signal of the first electrode, the second closed current signal of the second electrode, the second test current signal of the second electrode, and the second test current signal of the first electrode, the true signal generated by the oxygen molecule reaction of the second electrode is determined.

2. The method for extending service life and reducing noise signals as described in claim 1, characterized in that, The actual signal generated by the oxygen molecule reaction at the first electrode is: A = A' - B0n1 - (A01 - B01); Where A' is the first test current signal of the first electrode, B0n1 is the first test current signal of the second electrode, A01 is the first closed current signal of the first electrode, B01 is the first closed current signal of the second electrode, and A is the actual signal generated by the oxygen molecule reaction of the first electrode.

3. The method for extending service life and reducing noise signals as described in claim 1, characterized in that, The first closed current signal of the first electrode and the first closed current signal of the second electrode change synchronously with temperature.

4. The method for extending service life and reducing noise signals as described in claim 1, characterized in that, The actual signal generated by the oxygen molecule reaction at the second electrode is: B = B' - A0n2 - (B02 - A02); Wherein, B' is the second test current signal of the second electrode, A0n2 is the second test current signal of the first electrode, A02 is the second closed current signal of the first electrode, B02 is the second closed current signal of the second electrode, and B is the actual signal generated by the oxygen molecule reaction of the second electrode.

5. The method for extending service life and reducing noise signals as described in claim 1, characterized in that, The second closed current signal of the first electrode and the second closed current signal of the second electrode change synchronously with temperature.

6. An electrochemical oxygen sensor, characterized in that, include: Utilizing a first electrode and a second electrode installed within the same sensor housing; The first electrode and the second electrode are arranged isolated from each other within the sensor housing, with the first electrode arranged in a first space and the second electrode arranged in a second space. The first space has a first air inlet and a first air outlet, and the second space has a second air inlet and a second air outlet. The first air inlet, the second air inlet, the first air outlet and the second air outlet are respectively provided with corresponding plugs. The first electrode is connected to the first electrode lead, and the second electrode is connected to the second electrode lead; The first electrode and the second electrode are sealed separately to obtain the first sealing current signal of the first electrode and the first sealing current signal of the second electrode. The test gas is introduced into the first electrode, and the second electrode is kept closed, so that the first test current signal of the first electrode and the first test current signal of the second electrode are obtained. Based on the first closed current signal of the first electrode, the first closed current signal of the second electrode, the first test current signal of the first electrode, and the first test current signal of the second electrode, the actual signal generated by the oxygen molecule reaction of the first electrode is determined. When the attenuation of the current signal of the first electrode is greater than the set threshold, the first electrode and the second electrode are individually closed to obtain the second closed current signal of the first electrode and the second closed current signal of the second electrode. Then, the test gas is introduced into the second electrode while the first electrode remains closed, and the second test current signal of the second electrode and the second test current signal of the first electrode are obtained. Based on the second closed current signal of the first electrode, the second closed current signal of the second electrode, the second test current signal of the second electrode, and the second test current signal of the first electrode, the true signal generated by the oxygen molecule reaction of the second electrode is determined.

7. The electrochemical oxygen sensor as described in claim 6, characterized in that, The first closed current signal of the first electrode and the first closed current signal of the second electrode change synchronously with temperature; the second closed current signal of the first electrode and the second closed current signal of the second electrode change synchronously with temperature.

8. An oxygen permeability testing device, characterized in that, Including the electrochemical oxygen sensor as described in claim 6.

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