An ozone gas titration standard device and traceability method

Abstract

The present invention provides an ozone gas-phase titration standard device and a traceability method, belonging to the technical field of accurate measurement standards for ozone concentration. It includes: a high-pressure gas cylinder of nitric oxide standard gas, which is respectively connected to a gas-phase titration chamber and a four-way valve; a high-pressure gas cylinder of nitrogen dioxide standard gas, which is respectively connected to the gas-phase titration chamber and the four-way valve. The gas-phase titration chamber is connected to the four-way valve, and the four-way valve is also respectively connected to a nitric oxide analyzer and a nitrogen dioxide analyzer; an ozone generator, which is respectively connected to the gas-phase titration chamber, a standard ozone gas analyzer, and a to-be-tested ozone gas analyzer. Since the present invention measures the ozone gas concentration by measuring the reduction amount of nitric oxide and the increase amount of nitrogen dioxide, it avoids the influence of the system deviation of the nitrogen dioxide gas analyzer and the nitric oxide gas analyzer on the measurement of the ozone gas concentration; by introducing nitrogen dioxide standard gas to improve the initial test value of the nitrogen dioxide gas analyzer, the measurement accuracy can be significantly improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of accurate measurement standards for ozone concentration, and particularly relates to an ozone gas-phase titration standard device and a traceability method. Background Art

[0002] Existing traceability methods for ozone concentration measurement standards are divided into two categories. One category is based on Lambert-Beer's law, which relates the accurate measurement of ozone concentration to various physical parameters and spectral absorption coefficients in Lambert-Beer's law. For example, the ozone standard photometer (SRP) metrological reference device adopted globally has a range not exceeding 1 μmol / mol. The other category uses the quantitative and rapid reaction of ozone and nitric oxide for gas-phase titration to trace the ozone concentration to the concentration of nitric oxide standard gas. Currently, the range of such devices does not exceed 1 μmol / mol, and only a nitrogen dioxide analyzer is used to measure the generated nitrogen dioxide concentration. Due to the strong adsorption and poor stability of nitrogen dioxide and the influence of various factors during measurement, the uncertainty value of the measurement is relatively large. Summary of the Invention

[0003] The purpose of the present invention is to solve the problems existing in the above-mentioned prior art, and provide an ozone gas-phase titration standard device and a traceability method, which are an ozone gas-phase titration standard device and a traceability method from low concentration (ppb level) to high concentration (ppm level), especially for the accurate quantitative measurement of ozone gas higher than 1 μmol / mol. The method of the present invention has a self-verification function and can significantly improve the measurement accuracy.

[0004] The present invention is achieved through the following technical solutions:

[0005] In one aspect of the present invention, an ozone gas-phase titration standard device is provided, including:

[0006] A high-pressure gas cylinder of nitric oxide standard gas is connected to a gas-phase titration chamber and a four-way valve respectively;

[0007] A high-pressure gas cylinder of nitrogen dioxide standard gas is connected to a gas-phase titration chamber and a four-way valve respectively. The gas-phase titration chamber is connected to the four-way valve, and the four-way valve is also connected to a nitric oxide analyzer and a nitrogen dioxide analyzer respectively;

[0008] An ozone generator is connected to a gas-phase titration chamber, a standard ozone gas analyzer, and a to-be-tested ozone gas analyzer respectively.

[0009] A further improvement of the present invention lies in:

[0010] A first three-way joint is connected to the high-pressure gas cylinder of nitric oxide standard gas, and the first three-way joint is connected to a gas-phase titration chamber and a four-way valve respectively through gas pipelines;

[0011] A second three-way joint is connected to the high-pressure gas cylinder of the nitrogen dioxide standard gas, and the second three-way joint is respectively connected to the gas-phase titration chamber and the four-way valve through gas pipelines;

[0012] A four-way joint is connected to the ozone generator, and the four-way joint is respectively connected to the gas-phase titration chamber, the standard ozone gas analyzer and the ozone gas analyzer to be tested through gas pipelines;

[0013] A third three-way joint is further connected to the gas-phase titration chamber, and the third three-way joint is respectively connected to the back pressure valve and the four-way valve through gas pipelines; A fourth three-way joint is further connected to the four-way valve, and the fourth three-way joint is respectively connected to the nitric oxide gas analyzer and the nitrogen dioxide gas analyzer through gas pipelines.

[0014] A further improvement of the present invention lies in:

[0015] The four-way valve has four interfaces, namely the first interface, the second interface, the third interface and the fourth interface. During operation, only one of the first interface, the second interface and the fourth interface is connected to the third interface.

[0016] A further improvement of the present invention lies in:

[0017] After the high-pressure gas cylinder of the nitric oxide standard gas is connected to the first three-way joint, it is respectively connected to the gas-phase titration chamber and the second interface of the four-way valve through gas pipelines.

[0018] A further improvement of the present invention lies in:

[0019] After the high-pressure gas cylinder of the nitrogen dioxide standard gas is connected to the second three-way joint, it is respectively connected to the gas-phase titration chamber and the fourth interface of the four-way valve through gas pipelines.

[0020] A further improvement of the present invention lies in:

[0021] After the gas-phase titration chamber is connected to the third three-way joint through a gas pipeline, one way is connected to the back pressure valve through a gas pipeline and then emptied through a gas pipeline, and the other way is connected to the first interface of the four-way valve through a gas pipeline.

[0022] A further improvement of the present invention lies in:

[0023] After the third interface of the four-way valve is connected to the fourth three-way joint through a gas pipeline, it is respectively connected to the nitrogen dioxide gas analyzer and the nitric oxide gas analyzer through gas pipelines.

[0024] In the second aspect of the present invention, a method for tracing the concentration of ozone gas is provided, and the specific steps are as follows:

[0025] Step 1, the nitric oxide standard gas and the ozone generated by the ozone generator are subjected to gas-phase titration in the gas-phase titration chamber:

[0026] NO + O3 → NO2 + O2 (1)

[0027] Control the amount of ozone entering the gas-phase titration chamber so that it is not higher than the amount of nitric oxide standard gas entering the gas-phase titration chamber;

[0028] Step 2: By controlling the four-way valve, connect the second interface to the third interface so that the concentration of the nitric oxide standard gas can be measured by the nitric oxide gas analyzer to calibrate the nitric oxide gas analyzer to make its measurement accurate; and record the concentration value of the nitric oxide standard gas, denoted as C NO.0 ;

[0029] Step 3: By controlling the four-way valve, connect the fourth interface to the third interface so that the concentration of the nitrogen dioxide standard gas can be measured by the nitrogen dioxide gas analyzer to calibrate the nitrogen dioxide gas analyzer to make its measurement accurate; and record the concentration value of the nitrogen dioxide standard gas, denoted as C NO2.0 ;

[0030] Step 4: By controlling the four-way valve, connect the first interface to the third interface so that the concentration of nitric oxide gas in the gas after gas-phase titration in the gas-phase titration chamber is measured by the nitric oxide gas analyzer, and record the nitric oxide gas concentration value, denoted as C NO.1 ; The concentration of nitrogen dioxide gas in this path of gas is measured by the nitrogen dioxide gas analyzer, and the nitrogen dioxide gas concentration value is recorded as C NO2.1 ;

[0031] Step 5: As can be seen from equation (1),

[0032] C O3.1 = C NO.0 - C NO.1 (2)

[0033] C O3.2 = C NO2.1 - C NO2.0 (3)

[0034] C O3.D = C O3.1 - C O3.2 (4)

[0035] where C O3.1 and C O3.2 are ozone concentrations; C O3.D is the difference between two ozone concentration values;

[0036] Step 6: When C O3.D obtained from equation (4) is 0, then take C O3.1 as the ozone gas concentration value generated by the ozone generator, and this C O3.1The value is used to calibrate the standard value of the standard ozone gas analyzer and also serves as the standard value for calibrating the ozone gas analyzer under test;

[0037] Step 7, when the C obtained from Equation (4) O3.D is not 0, then calculate C according to Equations (5), (6), and (7) O3.E1 and C O3.E2

[0038] C O3.M =(C O3.1 +C O3.2 ) / 2 (5)

[0039] C O3.E1 =(C O3.1 -C O3.M ) / C O3.M (6)

[0040] C O3.E2 =(C O3.2 -C O3.M ) / C O3.M (7)

[0041] If both the C O3.E1 value and the C O3.E2 value are within the measurement error range, then take C O3.M as the ozone gas concentration value generated by the ozone generator. This C O3.M value is used to calibrate the standard value of the standard ozone gas analyzer and also serves as the standard value for calibrating the ozone gas analyzer under test.

[0042] A further improvement of the present invention lies in:

[0043] In Step 7, when the ozone concentration is in the range of 0 - 1000 ppb, the maximum allowable error MPE is ±5 ppb or ±5%; when the ozone concentration is in the range of 0 - 1000 ppm, the maximum allowable error MPE is ±2% FS.

[0044] Compared with the prior art, the beneficial effects of the present invention are:

[0045] (1) The ozone gas phase titration standard device and traceability method of the present invention enable the concentration of ozone gas to be traced back to time, flow rate, and amount of substance in moles, and the traceability chain is complete and clear;

[0046] (2) The ozone gas phase titration standard device and traceability method of the present invention have a self - verification function, making the measured ozone gas concentration accurate and reliable, and avoiding the influence of the measurement errors of the nitrogen dioxide gas analyzer and the nitric oxide gas analyzer themselves on the measurement results;

[0047] (3) Since the ozone gas concentration is measured by measuring the reduction of nitric oxide and the increase of nitrogen dioxide, the influence of the system deviation of the nitrogen dioxide gas analyzer and the nitric oxide gas analyzer on the measurement of the ozone gas concentration is avoided;

[0048] (4) Since the nitrogen dioxide standard gas is introduced, the initial value measured by the nitrogen dioxide gas analyzer is increased, and the problems of poor sensitivity and accuracy when analyzing low-concentration nitrogen dioxide gas are avoided.

[0049] (5) The device of the present invention can not only trace and calibrate the ozone concentration, but also detect and calibrate the ozone analyzer to be tested. Description of the Drawings

[0050] Figure 1 is a schematic structural diagram of the ozone gas phase titration standard device of the present invention.

[0051] In the figure, 1. high-pressure gas cylinder of nitric oxide standard gas, 2. high-pressure gas cylinder of nitrogen dioxide standard gas, 3. first three-way joint, 4. gas phase titration chamber, 5. second three-way joint, 6. third three-way joint, 7. back pressure valve, 8. four-way valve, 801. first interface, 802. second interface, 803. third interface, 804. fourth interface, 9. fourth three-way joint, 10. nitrogen dioxide gas analyzer, 11. nitric oxide gas analyzer, 12. ozone generator, 13. four-way joint, 14. standard ozone gas analyzer, 15. ozone gas analyzer to be tested. Detailed Embodiment

[0052] The present invention will be further described in detail below with reference to the drawings:

[0053]

Embodiment 1

[0054] The present invention provides an ozone gas phase titration standard device, as Figure 1 shown, including: high-pressure gas cylinder 1 of nitric oxide standard gas, high-pressure gas cylinder 2 of nitrogen dioxide standard gas, first three-way joint 3, gas phase titration chamber 4, second three-way joint 5, third three-way joint 6, back pressure valve 7, four-way valve 8, fourth three-way joint 9, nitrogen dioxide gas analyzer 10, nitric oxide gas analyzer 11, ozone generator 12, four-way joint 13 and standard ozone gas analyzer 14;

[0055] The high-pressure gas cylinder 1 of nitric oxide standard gas is connected with the first three-way joint 3, and the first three-way joint 3 is respectively connected with the gas phase titration chamber 4 and the four-way valve 8 through gas pipelines;

[0056] The high-pressure gas cylinder 2 of nitrogen dioxide standard gas is connected with the second three-way joint 5, and the second three-way joint 5 is respectively connected with the gas phase titration chamber 4 and the four-way valve 8 through gas pipelines;

[0057] A four-way joint 13 is connected to the ozone generator 12. The four-way joint 13 is respectively connected to the gas-phase titration chamber 4, the standard ozone gas analyzer 14, and the ozone gas analyzer to be tested 15 through gas pipelines. The ozone gas analyzer to be tested 15 is used to detect the ozone concentration.

[0058] A third three-way joint 6 is also connected to the gas-phase titration chamber 4. The third three-way joint 6 is respectively connected to the back pressure valve 7 and the four-way valve 8 through gas pipelines. A fourth three-way joint 9 is also connected to the four-way valve 8. The fourth three-way joint 9 is respectively connected to the nitric oxide gas analyzer 11 and the nitrogen dioxide gas analyzer 10 through gas pipelines.

[0059] The four-way valve 8 has four interfaces, namely the first interface 801, the second interface 802, the third interface 803, and the fourth interface 804. During operation, only one of the first interface 801, the second interface 802, and the fourth interface 804 is in communication with the third interface 803.

[0060] After the high-pressure gas cylinder 1 of the nitric oxide standard gas is connected to the first three-way joint 3, it is respectively connected to the gas-phase titration chamber 4 and the second interface 802 of the four-way valve 8 through gas pipelines.

[0061] After the high-pressure gas cylinder 2 of the nitrogen dioxide standard gas is connected to the second three-way joint 5, it is respectively connected to the gas-phase titration chamber 4 and the fourth interface 804 of the four-way valve 8 through gas pipelines.

[0062] After the gas-phase titration chamber 4 is connected to the third three-way joint 6 through a gas pipeline, one path is connected to the back pressure valve 7 through a gas pipeline and then emptied through a gas pipeline, and the other path is connected to the first interface 801 of the four-way valve 8 through a gas pipeline.

[0063] After the third interface 803 of the four-way valve 8 is connected to the fourth three-way joint 9 through a gas pipeline, it is respectively connected to the nitrogen dioxide gas analyzer 10 and the nitric oxide gas analyzer 11 through gas pipelines.

[0064] After the ozone generator 12 is connected to the four-way joint 13 through a gas pipeline, it is respectively connected to the gas-phase titration chamber 4, the standard ozone gas analyzer 14, and the ozone gas analyzer to be tested 15 through gas pipelines.

[0065] The gas flow direction in the ozone gas-phase titration standard device of the present invention is as follows:

[0066] The nitric oxide standard gas in the high-pressure gas cylinder 1 of nitric oxide standard gas enters the gas-phase titration chamber 4 after passing through the first three-way joint 3; the nitrogen dioxide standard gas in the high-pressure gas cylinder 2 of nitrogen dioxide standard gas enters the gas-phase titration chamber 4 after passing through the second three-way joint 5; the ozone gas generated by the ozone generator 12 enters the gas-phase titration chamber 4 after passing through the four-way joint 13; the gas coming out of the gas-phase titration chamber 4 enters the first interface 801 of the four-way valve 8 after passing through the third three-way joint 6. When the first interface 801 is connected to the third interface 803, the gas enters the nitrogen dioxide gas analyzer 10 and the nitric oxide gas analyzer 11 respectively after passing through the fourth three-way joint 9; the gas coming out of the gas-phase titration chamber 4 can also be emptied after passing through the back-pressure valve 7;

[0067] The nitric oxide standard gas in the high-pressure gas cylinder 1 of nitric oxide standard gas enters the second interface 802 of the four-way valve 8 after passing through the first three-way joint 3. When the second interface 802 is connected to the third interface 803, the gas enters the nitrogen dioxide gas analyzer 10 and the nitric oxide gas analyzer 11 respectively after passing through the fourth three-way joint 9;

[0068] The nitrogen dioxide standard gas in the high-pressure gas cylinder 2 of nitrogen dioxide standard gas enters the fourth interface 804 of the four-way valve 8 after passing through the second three-way joint 5. When the fourth interface 804 is connected to the third interface 803, the gas enters the nitrogen dioxide gas analyzer 10 and the nitric oxide gas analyzer 11 respectively after passing through the fourth three-way joint 9;

[0069] The ozone gas generated by the ozone generator 12 enters the standard ozone gas analyzer 14 after passing through the four-way joint 13; and another way enters the ozone gas analyzer 15 to be tested.

[0070]

Embodiment 2

[0071] The present invention also provides a method for tracing the concentration of ozone gas, which is carried out according to the following steps:

[0072] Step 1, the nitric oxide standard gas and the ozone generated by the ozone generator 12 are subjected to gas-phase titration in the gas-phase titration chamber 4:

[0073] NO + O3 → NO2 + O2 (1)

[0074] Control the amount of ozone entering the gas-phase titration chamber 4 so that it is not higher than the amount of nitric oxide standard gas entering the gas-phase titration chamber 4;

[0075] Step 2: By controlling the four-way valve 8, connect the second interface 802 to the third interface 803, so that the concentration of the nitric oxide standard gas can be measured by the nitric oxide gas analyzer 11, for calibrating the nitric oxide gas analyzer 11 to make its measurement accurate (Calibration of the nitric oxide analyzer 11: Pass the nitric oxide standard gas through the nitric oxide analyzer, and adjust and calibrate the indication value of the instrument according to the concentration value of the nitric oxide standard gas); and record the concentration value of the nitric oxide standard gas, denoted as C NO.0 ;

[0076] Step 3: By controlling the four-way valve 8, connect the fourth interface 804 to the third interface 803, so that the concentration of the nitrogen dioxide standard gas can be measured by the nitrogen dioxide gas analyzer 10, for calibrating the nitrogen dioxide gas analyzer 10 to make its measurement accurate (Calibration of the nitrogen dioxide analyzer 10: Pass the nitrogen dioxide standard gas through the nitrogen dioxide analyzer, and adjust and calibrate the indication value of the instrument according to the concentration value of the nitrogen dioxide standard gas); and record the concentration value of the nitrogen dioxide standard gas, denoted as C NO2.0 ;

[0077] Step 4: By controlling the four-way valve 8, connect the first interface 801 to the third interface 803, so that the concentration of nitric oxide gas in the gas (which is a mixed gas of nitric oxide, nitrogen dioxide, ozone and oxygen at this time) after gas-phase titration in the gas-phase titration chamber 4 is measured by the nitric oxide gas analyzer 11, and record the nitric oxide gas concentration value, denoted as C NO.1 ; The concentration of nitrogen dioxide gas in this path of gas is measured by the nitrogen dioxide gas analyzer 10, and the nitrogen dioxide gas concentration value is recorded as C NO2.1 ;

[0078] Step 5: As can be seen from Equation (1),

[0079] C O3.1 = C NO.0 - C NO.1 (2)

[0080] C O3.2 = C NO2.1 - C NO2.0 (3)

[0081] C O3.D = C O3.1 - C O3.2 (4)

[0082] Among them, C O3.1 and C O3.2 are the ozone concentrations; C O3.D is the difference between two ozone concentration values.

[0083] Theoretically, the ozone concentration C O3.Dshould be 0, that is, the reduced value of the nitric oxide gas concentration should be equal to the increased value of the nitrogen dioxide gas concentration, and these two values should be equal to the measured ozone concentration value. In practice, affected by factors such as the measurement linear range, accuracy, stability, resolution, and response time of the nitrogen dioxide gas analyzer 10 and the nitric oxide gas analyzer 11, the values obtained from Equation (2) and Equation (3) may be different, that is, the C obtained from Equation (4) O3.D is not 0.

[0084] Step 6, when the C obtained from Equation (4) O3.D is 0, then take C O3.1 as the ozone gas concentration value generated by the ozone generator 12. This C O3.1 value is used to calibrate the standard value of the standard ozone gas analyzer 14 and can also be used as the standard value for calibrating the ozone gas analyzer 15 to be inspected.

[0085] It is easy to see that the ozone gas concentration value is traced back to the nitric oxide standard gas through the nitric oxide gas analyzer 11. The total amount of the nitric oxide standard gas is traced back to time, flow rate, and molar concentration, so its traceability chain is complete and clear; similarly, the ozone gas concentration value is traced back to the nitrogen dioxide standard gas through the nitrogen dioxide gas analyzer 10. The mass of the nitrogen dioxide standard gas is traced back to time, flow rate, and molar concentration, so its traceability chain is complete and clear; and the ozone gas concentration value is mutually verified through the nitric oxide standard gas and the nitrogen dioxide standard gas, realizing the "self-verification" function, avoiding measurement errors caused by factors such as the measurement linearity, accuracy, stability, resolution, and response time of the nitrogen dioxide gas analyzer 10 and the nitric oxide gas analyzer 11.

[0086] Step 7, when the C obtained from Equation (4) O3.D is not 0, then calculate C O3.E1 and C O3.E2

[0087] C O3.M =(C O3.1 +C O3.2 ) / 2 (5)

[0088] C O3.E1 =(C O3.1 -C O3.M ) / C O3.M (6)

[0089] C O3.E2 =(C O3.2 -C O3.M ) / C O3.M (7)

[0090] If the C O3.E1 value and the C O3.E2The values are all within the measurement error range (when the ozone concentration is in the range of 0 - 1000 ppb, the maximum allowable error MPE is ±5 ppb or ±5%; when the ozone concentration is in the range of 0 - 1000 ppm, the maximum allowable error MPE is ±2% FS), then take C O3.M as the ozone gas concentration value generated by the ozone generator, and this C O3.M value is used to calibrate the standard value of the standard ozone gas analyzer 14, and can also be used as the standard value for calibrating the ozone gas analyzer 15 to be inspected.

[0091] It is easy to see that, similar to step 6, the ozone gas concentration value is traced back to time, flow rate, and amount of substance in moles respectively, so its traceability chain is clear and complete; and it has a "self-verification" function to avoid measurement errors caused by factors such as the measurement linearity, accuracy, stability, resolution, and response time of the nitrogen dioxide gas analyzer 10 and the nitric oxide gas analyzer 11.

[0092] If C O3.E1 value and C O3.E2 value, any one of them exceeds the allowable measurement error range, then check the nitrogen dioxide gas analyzer 10 and the nitric oxide gas analyzer 11. After eliminating their measurement faults, conduct tests according to steps 6 and 7.

[0093] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0094] Finally, it should be noted that the above technical solution is only one implementation manner of the present invention. For those skilled in the art, based on the disclosed application methods and principles of the present invention, it is very easy to make various types of improvements or deformations, not limited to the methods described in the above specific implementation manner of the present invention. Therefore, the above-described manner is only preferred and does not have a restrictive meaning.

Claims

1. An ozone gas titration standard device, characterized in that, The ozone gas-phase titration standard device includes: A high-pressure cylinder of nitric oxide standard gas, which is respectively connected to a gas-phase titration chamber and a four-way valve; a first three-way joint is connected to the high-pressure cylinder of nitric oxide standard gas, and the first three-way joint is respectively connected to the gas-phase titration chamber and the four-way valve through gas pipelines; A high-pressure cylinder of nitrogen dioxide standard gas, which is respectively connected to the gas-phase titration chamber and the four-way valve, the gas-phase titration chamber is connected to the four-way valve, and the four-way valve is also respectively connected to a nitric oxide gas analyzer and a nitrogen dioxide gas analyzer; a second three-way joint is connected to the high-pressure cylinder of nitrogen dioxide standard gas, and the second three-way joint is respectively connected to the gas-phase titration chamber and the four-way valve through gas pipelines; An ozone generator, a four-way joint is connected to the ozone generator, and the four-way joint is respectively connected to the gas-phase titration chamber, a standard ozone gas analyzer and a to-be-tested ozone gas analyzer through gas pipelines; A third three-way joint is further connected to the gas-phase titration chamber, and the third three-way joint is respectively connected to a back pressure valve and the four-way valve through gas pipelines; a fourth three-way joint is also connected to the four-way valve, and the fourth three-way joint is respectively connected to the nitric oxide gas analyzer and the nitrogen dioxide gas analyzer through gas pipelines; The four-way valve has four interfaces, namely a first interface, a second interface, a third interface and a fourth interface. During operation, only one of the first interface, the second interface and the fourth interface is in communication with the third interface; After the high-pressure cylinder of nitric oxide standard gas is connected to the first three-way joint, it is respectively connected to the gas-phase titration chamber and the second interface of the four-way valve through gas pipelines; After the high-pressure cylinder of nitrogen dioxide standard gas is connected to the second three-way joint, it is respectively connected to the gas-phase titration chamber and the fourth interface of the four-way valve through gas pipelines.

2. The ozone gas titration standard device according to claim 1, wherein After the gas-phase titration chamber is connected to the third three-way joint through a gas pipeline, one path is connected to the back pressure valve through a gas pipeline and then emptied through a gas pipeline, and the other path is connected to the first interface of the four-way valve through a gas pipeline.

3. The standard device for ozone gas titration according to claim 1, characterized in that, After the third interface of the four-way valve is connected to the fourth three-way joint through a gas pipeline, it is respectively connected to the nitrogen dioxide gas analyzer and the nitric oxide gas analyzer through gas pipelines.

4. A method for tracing the concentration of ozone gas, characterized in that, Using the ozone gas-phase titration standard device according to any one of claims 1-3 to trace the concentration of ozone gas, the specific steps of the method are as follows: Step 1, gas-phase titration of nitric oxide standard gas and ozone generated by the ozone generator in the gas-phase titration chamber: NO + O3 → NO2 + O2 (1) Control the amount of ozone entering the gas-phase titration chamber so that it is not higher than the amount of nitric oxide standard gas entering the gas-phase titration chamber; Step 2: By controlling the four-way valve, connect the second interface to the third interface so that the concentration of the nitric oxide standard gas can be measured by the nitric oxide gas analyzer, for calibrating the nitric oxide gas analyzer to make its measured value accurate; and record the concentration value of the nitric oxide standard gas, denoted as C NO.0 ; Step 3: By controlling the four-way valve, connect the fourth interface to the third interface so that the concentration of the nitrogen dioxide standard gas can be measured by the nitrogen dioxide gas analyzer, for calibrating the nitrogen dioxide gas analyzer to make its measured value accurate; and record the concentration value of the nitrogen dioxide standard gas, denoted as C NO2.0 ; Step 4: By controlling the four-way valve, connect the first interface to the third interface, so that the concentration of nitric oxide gas in the gas after gas-phase titration in the gas-phase titration chamber is measured by a nitric oxide gas analyzer, and the nitric oxide gas concentration value is recorded as C NO.1 ; The concentration of nitrogen dioxide gas in this gas path is measured by a nitrogen dioxide gas analyzer, and the nitrogen dioxide gas concentration value is recorded as C NO2.1 ; In step 5, as can be seen from formula (1), C O3.1 = C NO.0 - C NO.1 (2) C O3.2 = C NO2.1 - C NO2.0 (3) C O3.D = C O3.1 - C O3.2 (4) Among them, C O3.1 and C O3.2 are ozone concentrations; C O3.D is the difference between two ozone concentration values; Step 6, when C obtained from formula (4) O3.D is 0, then take C O3.1 as the concentration value of ozone gas generated by the ozone generator, and this C O3.1 value is used to calibrate the standard value of the standard ozone gas analyzer and also serves as the standard value for calibrating the ozone gas analyzer to be tested; Step 7, when C obtained from formula (4) O3.D is not 0, then calculate C according to formulas (5), (6) and (7) O3.E1 and C O3.E2 ; C O3.M = (C O3.1 + C O3.2 ) / 2 (5) C O3.E1 = (C O3.1 - C O3.M ) / C O3.M (6) C O3.E2 = (C O3.2 - C O3.M ) / C O3.M (7) If C O3.E1 value and C O3.E2 value are both within the measurement error range, then take C O3.M as the ozone gas concentration value generated by the ozone generator. This C O3.M value is used to calibrate the standard value of the standard ozone gas analyzer and also serves as the standard value for calibrating the ozone gas analyzer under test.

5. A method for tracing the concentration of ozone gas according to claim 4, characterized in that, In step 7, when the ozone concentration is in the range of 0-1000 ppb, the maximum allowable error MPE is ±5 ppb or ±5%; when the ozone concentration is in the range of 0-1000 ppm, the maximum allowable error MPE is ±2% FS.

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