WO2020015030A1

WO2020015030A1 - Oxygen permeability testing device, system, and method

Info

Publication number: WO2020015030A1
Application number: PCT/CN2018/099575
Authority: WO
Inventors: 姜允中
Original assignee: 济南兰光机电技术有限公司
Priority date: 2018-07-16
Filing date: 2018-08-09
Publication date: 2020-01-23

Abstract

An oxygen permeability testing device, system, and method. The device comprises at least one testing cavity, a sensor assembly, and a switch component. The sensor assembly comprises at least two oxygen sensors (1, 3) connected in parallel and having different measuring ranges and/or precision. Oxygen passes through the testing cavity accommodating a sample, and connection pipelines between the testing cavity and the oxygen sensors (1, 3) are selectively controlled by the switch component to connect or disconnect. In the device, system, and method, a sensor having the most suitable measuring range and precision is selected to perform a test according to an oxygen concentration of a gas under test and a testing precision requirement. An apparatus utilizing a sensor set having the multiple oxygen sensors (1, 3) is capable of meeting testing requirements of various measuring ranges and precision.

Description

Oxygen transmission rate testing device, system and method

This application claims the priority of Chinese invention patent with application number 2018107792724 filed on July 16, 2018 and utility model patent with application number 2018211254274 filed on the same day.

Technical field

The invention relates to an oxygen transmission rate testing device, system and method.

Background technique

The barrier property of materials to oxygen is an important indicator of whether the materials are suitable for certain fields: for packaging materials, it directly affects the shelf life of the items in the package; for engineering materials such as oxygen barrier pipes, it means that tap water is in the pipeline Whether it is susceptible to oxidation and deterioration during transportation; for materials that require flame retardancy such as building materials, ships, vehicles, and home appliances, the barrier to oxygen means whether the flame retardant index has been reached and whether there are hidden safety hazards. For some special electronic components, after being oxidized and corroded, the electrical properties such as the resistance of the components are affected. The basic method for testing a material's oxygen permeability (ie, the material's barrier to oxygen) is to measure the amount of oxygen in the gas that has penetrated the material. There are many test methods, and domestic and international standards have determined the use of electrochemical oxygen sensors to detect the oxygen barrier performance of packaging materials.

The core component of the entire test is an oxygen sensor. The performance and accuracy of the sensor directly determines the performance and accuracy of the entire instrument. The advantages of electrochemical oxygen sensors are high detection accuracy, which can reach the level of ppm (ie, parts per million / concentration). The disadvantage is that the sensor consumes fast, and each oxygen molecule detected by the sensor and the sensor's actives occur. The chemical reaction consumes the active substance in the sensor. If too many oxygen molecules enter the sensor, the active substance will be consumed quickly. A ppm-level electrochemical oxygen sensor can normally work for about 2 years, but if it is exposed to the air, it will be completely scrapped within one day.

When testing the oxygen permeability of high-barrier materials, the molecular weight of oxygen permeating through the sample is relatively small. In order to ensure the detection accuracy, it is desirable that all oxygen molecules enter the sensor reaction as much as possible. This can generate a relatively large current signal and output a current signal. The difficulty of processing will be reduced, and measurement results close to the absolute true value can be obtained. This electrochemical sensor, which reacts with almost all oxygen molecules entering it, has a small range and high accuracy. For low-barrier materials, the molecular weight of the transmitted oxygen is large. If all the oxygen molecules react with the sensor, it will greatly reduce the life of the sensor, so only a certain percentage of the oxygen molecules enter the sensor and the active material of the sensor reacts. Part of the oxygen reacts with the sensor to produce an electrical signal. It is not known what percentage of the oxygen actually reacts with the sensor. Processing of current signal data in the later stages is difficult, resulting in large detection errors. This sensor has a large range and low accuracy.

The technical difficulties of the oxygen barrier performance testing instruments for packaging materials are:

At present, only one oxygen sensor is installed in an oxygen transmission rate test instrument, which cannot take into account the large-scale and high-precision detection requirements;

At the same time, when the sensor is disassembled, the sensor is inevitably exposed to the air, and a large amount of oxygen enters the system pipeline, which greatly reduces the life of the sensor. An instrument cannot achieve a variety of ranges by frequently disassembling and disassembling oxygen sensors with different measuring ranges. A variety of precision detection.

The corresponding test instrument only has one oxygen sensor installed, and the sensor will be quickly consumed and scrapped. Frequent scrapping and replacement of the sensor will undoubtedly increase the customer's use and maintenance costs.

Summary of the invention

In order to solve the above problems, the present invention proposes an oxygen transmission rate test device, system, and method. The present invention changes the problem that one device uses one sensor in the past, and cannot take into account the problems of large range and high accuracy. Single sensor, the problem of fast sensor loss and short life.

In order to achieve the above objective, the present invention adopts the following technical solutions:

The invention provides an oxygen transmission rate testing device, which includes at least one test chamber, a sensor component, and a switching device. The sensor component includes at least two oxygen sensors with different ranges or / and different accuracy in parallel. The selection of the test chamber through the switch device controls the on-off of the connection pipeline connecting the test chamber with each oxygen sensor. Use an oxygen sensor whose range or / and accuracy is adapted to the concentration of the gas to be tested for detection.

Further, there are at least three oxygen sensors connected in parallel in the sensor assembly, and at least the range or accuracy is different between each two oxygen sensors.

Further, the sensor assembly includes at least two oxygen sensor branches connected in parallel, and at least one oxygen sensor branch includes a plurality of oxygen sensors connected in series, and the accuracy of the series of oxygen sensors increases in order along the airflow direction.

Further, the sensor assembly includes at least two oxygen sensor branches connected in parallel, and at least one oxygen sensor branch includes a plurality of oxygen sensor units connected in series, and each oxygen sensor unit is an oxygen sensor or a plurality of oxygen sensors connected in parallel, Along the airflow direction, the accuracy of the series of oxygen sensors increases in sequence.

Further, there are multiple test chambers, and the test chambers are connected in parallel, and each test chamber is connected to the sensor assembly through a respective connection pipeline.

Further, the switching device is a selection switch, a three-way valve, or a switch matrix.

Of course, those skilled in the art can improve the selection of the above-mentioned switching devices on the basis of the present invention. For example, a solenoid valve is provided on the connecting pipe of each oxygen sensor or a branch of the oxygen sensor group. Electricity, to control the conduction of the connecting pipeline, etc., all belong to the simple replacement by those skilled in the art and should belong to the protection scope of the present invention.

Further, the test device further includes at least one exhaust pipe connected to the test chamber, and directly discharges the gas in the lower chamber of the test chamber.

Further, the test device further includes an oxygen inlet line, and each oxygen inlet line is in communication with the upper cavity of the test cavity to send oxygen.

Further, the test device further includes a carrier gas (the carrier gas may be an inert gas such as nitrogen, helium, etc., and the present invention takes nitrogen as an example) pipeline, and each of the carrier gas pipelines communicates with the lower chamber of the test chamber and is fed into the carrier. gas.

Further, the sensor component is in direct communication with the carrier gas pipeline through a gas path.

Further, a control valve is provided on the connecting pipeline and the air circuit.

The invention provides an oxygen transmission rate test system, which includes the above-mentioned test device and a data processor. The data processor is connected to each oxygen sensor, receives its detection data, and obtains test results based on the data of each oxygen sensor.

The present invention provides a method for testing oxygen transmission rate, including the following steps:

1) The test gas flows into the upper chamber: oxygen enters the upper chamber of each test chamber until the gas in the test chamber is stable;

2) Purge the lower cavity with carrier gas: nitrogen carrier gas flows through the lower cavity of each test cavity;

3) Obtain the zero value: start the test, introduce the lower chamber gas into the atmosphere, and select an oxygen sensor whose range matches the oxygen transmission amount. At this time, the oxygen concentration read by the oxygen sensor is the zero line oxygen concentration value z, which will be stable. The subsequent z value is recorded as the zero oxygen concentration;

4) Measure the oxygen concentration of the sample penetration: Introduce the zero point gas path to the atmosphere, and introduce the gas in the lower chamber to the corresponding oxygen sensor. At this time, the oxygen concentration read by the oxygen sensor is the infiltration of the sample between the upper and lower chambers. The oxygen concentration value a, the value of a when the recording is stable is recorded as the oxygen concentration of the sample, and the difference between the oxygen concentration value a and the zero oxygen concentration z is the oxygen concentration penetrated by the sample.

Further, when the oxygen permeation amount of the sample is unknown, the first oxygen sensor with a larger range is selected to test the zero oxygen concentration, and then the permeate oxygen concentration is measured. If the measured oxygen concentration value a in the test cavity is greater than the range, The maximum range of the small second oxygen sensor continues to be measured by the first oxygen sensor;

If it is found that the oxygen concentration value a in the test chamber is within the measurement range of the second oxygen sensor, the gas is introduced into the second oxygen sensor and the above test process is repeated. Both the oxygen concentration value a and the zero oxygen concentration z should be determined by the smaller range. Dioxin sensor.

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

1. The present invention can realize total absorption measurement. According to the oxygen concentration of the gas to be measured and the need for detection accuracy, selecting an appropriate range and accuracy sensor detection can effectively improve the accuracy of the oxygen transmission rate test;

2. The present invention can realize a sensor group using multiple oxygen sensors in one device, which can meet the detection requirements of multiple ranges and multiple precisions, and solves the problem that a single device uses one sensor in the past, which cannot take into account the large range and high accuracy. ; It also solves the problems of fast sensor loss and short life using a single sensor in traditional equipment;

3. The present invention provides series and parallel oxygen sensors to form detection branches with different ranges or / and accuracy. The modular design can be used to flexibly change the test accuracy or range of the sensor to achieve customization and meet multiple ranges and multiple This kind of accuracy requires detection.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which form a part of this application, are used to provide further understanding of the application. The schematic embodiments of the application and the descriptions thereof are used to explain the application, and do not constitute an improper limitation on the application.

FIG. 1 is a schematic diagram of Embodiment 1 of the present invention;

2 is a schematic diagram of Embodiment 2 of the present invention;

3 is a schematic diagram of a third embodiment of a sensor group according to the present invention;

4 is a schematic diagram of a fourth embodiment of a sensor group according to the present invention;

5 is a schematic diagram of a fifth embodiment of a sensor group according to the present invention;

6 is a schematic diagram of Embodiment 6 of a sensor group according to the present invention;

Among them: 1, first oxygen sensor, 2, valve IV, 3, second oxygen sensor, 4, pipeline I, 5, three-way valve I, 6, valve I, 7, pipeline II, 8, lower cavity I , 9, pipeline III, 10, pipeline IV, 11, pipeline V, 12, pipeline VI, 13, valve II, 14, pipeline VII, 15, pipeline VIII, 16, valve III, 17, three Port valve II, 18, three-way valve III, 19, line IX, 20, line X, 21, line XI, 22, line XII, 23, line XIII, 24, three-way valve IV, 25, Pipeline XIV, 26. Data processing system, 27. Upper cavity I, 28. Upper cavity II, 29. Lower cavity II, 30. Pipeline XV, 31. Valve VI, 32. Pipeline XVI.

1-1. Three-way valve, 4-1. Data processing system, 5-1. Sensor III, 6-1. Sensor IV, 7-1. Sensor V, 8-1. Sensor VI, 9-1. Sensor VII 10-1. Sensor VIII, 11-1. Sensor IX, 12-1. Sensor X, 13-1. Sensor XI, 14-1. Sensor XII, 15-1. Sensor XIII, 16-1. Sensor XIV, 17-1. Sensor XV, 18-1. Sensor XVI, 19-1. Sensor XVII, 20-1. Sensor XVIII.

In the figure, air indicates air or atmosphere, O ₂ represents oxygen, and N ₂ represents nitrogen.

detailed description:

The present invention is further described below with reference to the accompanying drawings and embodiments.

It should be noted that the following detailed descriptions are all exemplary and are intended to provide further explanation of the present application. Unless defined otherwise, 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.

It should be noted that the terminology used herein is only for describing specific embodiments, and is not intended to limit the exemplary embodiments according to the present application. As used herein, the singular forms are intended to include the plural forms as well, unless the context clearly indicates otherwise, and it should also be understood that when the terms "including" and / or "including" are used in this specification, they indicate There are features, steps, operations, devices, components, and / or combinations thereof.

In the present invention, terms such as "up", "down", "left", "right", "front", "rear", "vertical", "horizontal", "side", "bottom" and the like indicate The orientation or positional relationship is based on the orientation or positional relationship shown in the drawings, and is only a relational term determined for the convenience of describing the structural relationship of each component or element of the present invention, and does not specifically refer to any component or element in the present invention, and cannot be understood as a reference to the present invention. Limitations of invention.

In the present invention, terms such as "fixed connection", "connected", "connected" and the like should be understood in a broad sense, and can mean fixed connection, integral connection or detachable connection; it can be directly connected, or through the middle. The media are indirectly connected. For a related scientific research or technical person in this field, the specific meanings of the above terms in the present invention may be determined according to specific conditions, and cannot be understood as a limitation on the present invention.

As pointed out in the background art, there is an existing oxygen transmission rate testing instrument for packaging materials, which has only one oxygen sensor. It cannot meet the requirements of large-scale and high-precision detection. It is unavoidable to be exposed to the air, and a large amount of oxygen enters the system pipeline, which greatly reduces the life of the sensor. It is impossible to achieve the detection of multiple ranges and multiple accuracy by frequently disassembling oxygen sensors with different ranges of accuracy. The sensor will be consumed quickly Scraping has increased many problems of maintenance costs.

The invention provides an oxygen transmission rate testing device with an oxygen sensor group, which includes a sensor group, a test cavity, and a gas path component. The sample is placed in the test chamber, and the gas that has penetrated the sample enters the sensor group through the gas path component. The sensing group includes at least a first oxygen sensor, a second oxygen sensor in parallel, and the range and / or accuracy of the first oxygen sensor and the second oxygen sensor are different. According to the oxygen concentration of the gas to be measured and the accuracy of the detection, the selection is more suitable. The range or / and accuracy of the sensor is detected.

The mentioned gas path assembly includes pipelines and valves, and the sensor group and test chamber are connected by pipelines. A valve is provided on the pipeline. The valve may include an on-off valve and a three-way valve. The on-off valve controls the closing and conduction of the corresponding pipeline, and the three-way valve selects the pipeline.

Of course, the selection and on-off of the corresponding pipeline can be controlled in other ways, such as each pipeline is connected to the sensor group separately, and each pipeline is provided with a solenoid valve.

Such a design can realize the use of multiple oxygen sensors in one device, which can meet the detection requirements of multiple ranges and multiple accuracy. Changed the problem that one device used one sensor in the past, which could not take into account the large range and high accuracy. It also solved the problems of fast sensor loss and short life when using a single sensor in traditional devices.

Of course, as a more preferred embodiment, the sensor group includes several sensors connected in series, and multiple ones can be connected in series. In theory, the more sensors connected in series, the more oxygen is absorbed by the sensor, the less excess oxygen is, and the detection of the sensor group is. The higher the accuracy.

When connected in series, the gas to be measured flows through each sensor in turn. The design principle of each sensor is that the range of the sensor flowing first is greater than the range of the sensor flowing later, but the accuracy of the sensor flowing later is higher than that of the sensor flowing first. The accuracy.

Such a design can ensure that a large range of sensors can absorb most of the oxygen first, and as the oxygen concentration becomes smaller and smaller, later sensors with higher accuracy can have a more accurate measurement.

As an implementation manner, the sensor group is a parallel-series sensor group, and the parallel-series sensor group has several parallel sensors. A parallel sensor may be a single sensor or a series sensor group.

As an embodiment, the sensor group is a series-parallel sensor group, and the series-parallel sensor group has several groups of series sensors, and a group of series sensors may be a single sensor or a parallel sensor group.

Then, an oxygen transmission rate test system is provided to transmit the data detected by the sensor group to a data processing system for processing. The oxygen transmission rate of the sample can be calculated automatically.

The oxygen sensor group has multiple oxygen sensors with inconsistent ranges or inconsistent accuracy. When measuring, first use a larger range oxygen sensor to measure to ensure that its detection range can withstand the oxygen concentration in the gas to be measured. The oxygen concentration in the gas is within the measurement range of an oxygen sensor, and the difference from the maximum range of the oxygen sensor is small, and it is switched to the oxygen sensor for measurement.

In terms of accuracy, you can first use an oxygen sensor that is close to the oxygen detection accuracy of the gas to be measured, but you must ensure that the measurement range of the oxygen sensor is greater than the oxygen concentration of the gas to be measured.

As a typical embodiment, the following implementations are used for detailed description.

Example 1

As shown in FIG. 2, an oxygen transmission rate testing device with an oxygen sensor group includes a sensor group, a test chamber, and a gas path component. The sample is placed in the test chamber, and the gas that has penetrated the sample enters the sensor group through the gas path component.

The sensing group includes the first oxygen sensor 1 and the second oxygen sensor 3 in parallel. The ranges of the first oxygen sensor 1 and the second oxygen sensor 3 are different, and the accuracy is different. According to the oxygen concentration of the gas to be measured and the accuracy of the detection, the choice is more Adaptive range and accuracy sensor detection. A variety of detection ranges and accuracy of an oxygen transmission rate test instrument. Pneumatic components include pipes and valves. One end of the pipeline III9, the pipeline V11 is connected to the upper cavity I27, and the other end of the pipeline V11 is connected to the atmosphere; the pipeline II7, the pipeline IV10 is connected to the lower cavity I8, and the pipeline II7 with the valve I6 is connected to the lower cavity I8 and the pipeline. VIII15, the pipeline VIII15 is provided with a valve III16 and a three-way valve III18 in sequence; the three-way valve III18 is divided into two ways: one way passes through the pipeline X20 to the sensor group, and the other way passes through the pipeline IX19 to the outside atmosphere; the pipeline IV10 is connected To the three-way valve I5, the three-way valve I5 is divided into two paths: one is connected to the pipeline X20 through the pipeline I4, and the other is connected to the external atmosphere through the pipeline XIII23.

The pipeline X20 is connected to a parallel sensor group through a three-way valve IV24. In the direction of air flow, a valve VI31 is connected behind the first oxygen sensor 1 and a valve IV2 is connected behind the second oxygen sensor 3.

The sensor group is also connected to a data processing system 26 to form a test system.

The test system works as follows:

1. Oxygen enters the upper chamber I27 from the pipeline III9, and is then discharged into the atmosphere through the pipeline V11. This process passes the test gas into the upper chamber of the test chamber.

2. Nitrogen flows through the lower chamber I8 through the valve I6, and then reaches the three-way valve I5 through the pipeline IV10. At the same time, nitrogen passes through the valve III16 to the three-way valve III18.

3. At the beginning of the test, the three-way valve I5 was connected to the pipeline XII23, and the lower chamber gas was introduced into the atmosphere. The three-way valve III18 is connected to the pipeline IX20, and the gas flows to the three-way valve IV24. Without knowing the approximate oxygen permeation amount of the sample, the three-way valve IV24 selects the first range of the first oxygen sensor 1 by default. The oxygen concentration read by the first oxygen sensor 1 of the process is the zero point oxygen concentration value z. After a period of nitrogen purge, the z value becomes stable and does not change. The z value at this time is recorded as the zero oxygen concentration.

4. The three-way valve III18 is switched, the pipeline VIII15 and the pipeline VIII19 are connected, the zero point gas path is introduced into the atmosphere, the three-way valve I5 is switched, the pipeline IV10 and the pipeline I4 are connected, and the gas in the lower chamber I8 is introduced into the three-way valve IV24 The three-way valve IV24 communicates with the large-range first oxygen sensor 1 by default. At this time, the oxygen concentration value read by the large-range first oxygen sensor 1 is a. After this process continues for a period of time, the value of a stabilizes and does not change. Let the value of a at this time be the measured oxygen concentration, and the difference az between the oxygen concentration value a and the zero oxygen concentration z is the oxygen concentration penetrated by the sample I.

If the oxygen concentration value a of the test chamber measured at this time is greater than the small-range second oxygen sensor 3, the three-way valve IV25 does not need to change state, and the normal test can be performed.

If it is found that the oxygen concentration value a in the test chamber is within the measurement range of the small-range second oxygen sensor 3, the three-way valve IV25 is switched, the pipeline IX20 and the pipeline XV32 are connected, and the gas is introduced into the small-range second oxygen sensor 3 and repeated In the above test process, the z and a values should be measured by the small-range second oxygen sensor 3. The calculation method is consistent with the measurement using the first oxygen sensor.

Example 2

As shown in Figure 1, an oxygen transmission rate test system with an oxygen sensor group can test multiple test chambers, including a sensor group, multiple test chambers (two shown in Figure 1), and gas.路组合。 Road components. The sample I is placed in the upper cavity I27 and the lower cavity I8, the sample II is placed in the upper cavity II28 and the lower cavity II29, and the gas that has penetrated the sample enters the sensor group through the gas path component, and the data detected by the sensor group Transfer to the data processing system for processing. The sensing group includes a first oxygen sensor, a second oxygen sensor connected in parallel, and the first oxygen sensor and the second oxygen sensor have different ranges and different accuracy. According to the oxygen concentration of the gas to be measured and the accuracy of the detection, a more appropriate selection is made. Equipped with range and accuracy sensor detection.

Pneumatic components contain multiple lines and valves. The pipeline III9, the pipeline V11 is connected to the upper cavity I27, the pipeline II7, the pipeline IV10 is connected to the lower cavity I8, the pipeline II7 with the valve I6 is connected to the lower cavity I8 and the pipeline VIII15, and the pipeline VIII15 is provided in this order Valve III16, three-way valve III18; three-way valve III18 is divided into two ways: one way to the sensor group through line IX20, and the other way to the outside atmosphere through line VIII19; line IV10 is connected to three-way valve I5, three-way valve I5 is divided into 2 channels: one is connected to pipeline IX20 through pipeline I4, and the other is connected to external atmosphere through pipeline XII23;

The pipeline IX20 is connected to a parallel sensor group through a three-way valve IV24. In the direction of the air flow, the first oxygen sensor is connected to the valve VI31 and the second oxygen sensor is connected to the valve IV2. The sensor group is also connected to a data processing system to process the sensor. data;

The pipeline V11 and the pipeline XIV30 are connected to the upper cavity II28, and the other end of the pipeline XIV30 is connected to the atmosphere; the pipeline VII14 and the pipeline VI12 with the valve II13 are connected to the lower cavity II29, and the other end of the pipeline VI12 is connected to the pipeline VIII15, the third end of pipeline VII14 is provided with three-way valve II17. Three-way valve II17 is divided into two paths: one is connected to line IX20 through line XI22, and the other is connected to the atmosphere through tube X21.

The working process is as follows:

1. Oxygen enters the upper cavity I27 from the pipeline III9, then enters the upper cavity II28 from the pipeline V11, and then is discharged into the atmosphere through the pipeline XIV30. This process passes the test gas into the upper cavity of the test cavity.

2. Nitrogen passes through valve I6 and valve II13, flows through lower chamber I8 and lower chamber II29, and then reaches three-way valve I5, three-way valve II17, and three-way valve III18 through valve III16.

3. At the beginning of the test, the three-way valve I5 and the three-way valve II17 were connected to the pipeline XIII23 and the pipeline XI21, respectively, and the lower chamber gas was introduced into the atmosphere. The three-way valve III18 is connected to the pipeline X20, and the gas flows to the three-way valve IV24. Without knowing the approximate oxygen permeation of the sample, the three-way valve IV24 selects the first oxygen sensor 1 with a large range by default. At this time, The oxygen concentration read by the large-scale first oxygen sensor 1 is the zero line oxygen concentration value z. After a period of nitrogen purge, the z value becomes stable and no longer changes. The z value at this time is recorded as the zero oxygen concentration.

4. The three-way valve III18 is switched and the line IX19 is connected, and the zero point gas path is introduced into the atmosphere. The three-way valve I5 is switched and the line I4 is connected. The gas in the lower chamber I8 is introduced into the three-way valve IV24 and the large-range first oxygen sensor 1 At this time, the oxygen concentration value of the lower cavity I8 read by the long-range first oxygen sensor 1 is a. After this process continues for a period of time, the value of a tends to be stable and no longer changes. The value of a at this time is measured as The oxygen concentration, the difference az between the oxygen concentration value a and the zero oxygen concentration z is the oxygen concentration penetrated by the sample I.

If the oxygen concentration value a of the test chamber measured at this time is larger than the range of the small-range second oxygen sensor 3, the three-way valve IV24 does not need to change the state, and the normal test can be performed.

If it is found that the oxygen concentration value a in the test chamber is within the measurement range of the small-range second oxygen sensor 3, the three-way valve IV24 is switched, and the pipeline X20 communicates with the pipeline XIV25, and the gas is introduced into the small-range second oxygen sensor 3. Repeat the above test process. Both z and a values should be measured by the small-range second oxygen sensor 3. The calculation method is consistent with the measurement using the first oxygen sensor.

5. The three-way valve I5 is switched to communicate with the pipeline XIII23, and the gas in the lower chamber I8 is introduced into the atmosphere. The three-way valve II17 is switched to communicate with the pipeline XII22, and the lower chamber gas in the lower chamber II29 is introduced into the three-way valve IV24. And the long-range first oxygen sensor 1 at this time, the long-range first oxygen sensor 1 reads the oxygen concentration value of the lower cavity II29 as b. After this process continues for a period of time, the b value stabilizes and no longer changes. The b value at this time is recorded as the measured oxygen concentration, and bz is the oxygen concentration permeated by sample II.

If the oxygen concentration value b of the test chamber measured at this time is larger than the range of the small-range second oxygen sensor 3, the three-way valve IV24 does not need to change the state, and the normal test can be performed.

If it is found that the oxygen concentration value b in the test chamber is within the measurement range of the small-range second oxygen sensor 3, the three-way valve IV24 is switched, the pipeline X20 is connected to the pipeline XIV25, and the gas is introduced into the small-range second oxygen sensor 3, and repeats In the above test process, z and b values should be measured by the small-range second oxygen sensor 3. The calculation method is consistent with the measurement using the first oxygen sensor.

Steps

4 and 5 test the oxygen gas into the oxygen sensor group for different times, so

steps

4 and 5 may be tested by different sensors. Of course, this embodiment is only an example. More test chambers can be added to ensure that the test chambers are independent of each other and can be connected in parallel in order. The connection methods of other test chambers to the connection pipeline and the data processing system can be given with reference to this drawing. The way.

Example 3

As shown in FIG. 3, on the basis of Embodiment 1 and Embodiment 2, the difference is that the sensor group includes multiple sensors in parallel, and three are shown in the figure. However, in other embodiments, it is also possible Expand to connect more sensors in parallel.

Example 4

As shown in FIG. 4, on the basis of Embodiment 1 and Embodiment 2, the difference is that the sensor group includes several sensors connected in series (multiple sensors can be connected in series, as shown in FIG. 3, in theory, the more sensors connected in series , The more oxygen is absorbed by the sensor, the less excess oxygen, the higher the detection accuracy of the sensor group). The rest is the same as in Example 1 or Example 2.

Example 5

As shown in FIG. 5, on the basis of Embodiment 1 and Embodiment 2, the difference is that the sensor group is a parallel-series sensor group, the parallel-series sensor group has several parallel sensors, and one parallel sensor may be a single sensor. Sensor or tandem sensor group.

For several electrochemical oxygen sensors connected in series, the gas to be measured flows through the sensors in sequence through the pipeline, and the range of the several sensors in series changes from large to small in order, and the accuracy of the sensor gradually increases. After the gas to be measured passes a sensor, the remaining oxygen is detected by the subsequent sensors. The more sensors in series, the more oxygen is absorbed by the sensor in the gas to be measured, the more thorough it is, the less excess oxygen is, and the sensor group is. The higher the detection accuracy.

Each sensor connected in parallel has a different range and different accuracy. According to the detection needs, select the sensor with the required accuracy and range. Such an oxygen transmission rate testing instrument can have a variety of detection ranges and accuracy.

Example 6

As shown in FIG. 6, on the basis of Embodiment 1 and Embodiment 2, the difference is that the sensor group is a series-parallel sensor group, the series-parallel sensor group has several groups of series sensors, and the group of series sensors may be Single sensor or parallel sensor group.

Of course, the above specific embodiments are merely examples. For example, in the above embodiments, the three-way valve is used to switch the pipeline, but in fact, a selector switch and multiple pipelines can also be used. Each pipeline is provided with a solenoid valve. By controlling the continuity of the connecting pipeline, etc., by powering the corresponding solenoid valve.

When selecting a corresponding switch or selecting a device or circuit, it should be adapted to the size of the measurement system, the layout of the pipeline, etc., so as to achieve optimization of multiple factors such as cost and pipeline design.

The above description is only a preferred embodiment of the present application, and is not intended to limit the present application. For those skilled in the art, this application may have various modifications and changes. Any modification, equivalent replacement, or improvement made within the spirit and principle of this application shall be included in the protection scope of this application.

Although the specific embodiments of the present invention are described above with reference to the accompanying drawings, they are not a limitation on the protection scope of the present invention. Those skilled in the art should understand that based on the technical solution of the present invention, those skilled in the art do not need to make creative work. Various modifications or variations that can be made are still within the protection scope of the present invention.

Claims

An oxygen transmission rate testing device is characterized in that it includes at least one test cavity, a sensor component, and a switching device. The sensor component includes at least two oxygen sensors with different ranges or / and different accuracy in parallel. The test chamber of the sample is controlled by the switch device to switch on and off the connecting pipeline connecting the test chamber and each oxygen sensor.
The oxygen transmission rate testing device according to claim 1, wherein there are at least three oxygen sensors connected in parallel in the sensor assembly, and at least the range or accuracy is different between each two oxygen sensors.
The oxygen transmission rate testing device according to claim 1, wherein the sensor component includes at least two oxygen sensor branches connected in parallel, at least one oxygen sensor branch includes a plurality of oxygen sensors connected in series, Along the airflow direction, the accuracy of the series of oxygen sensors increases in sequence.
The oxygen transmission rate testing device according to claim 1, wherein the sensor component includes at least two oxygen sensor branches connected in parallel, and at least one oxygen sensor branch includes a plurality of oxygen sensor units connected in series, Each oxygen sensor unit is an oxygen sensor or a plurality of oxygen sensors connected in parallel, and the accuracy of the series of oxygen sensors increases in order along the airflow direction.
The oxygen transmission rate testing device according to claim 1, characterized in that: there are a plurality of test chambers, and the test chambers are connected in parallel, and each test chamber is connected to At the sensor assembly.
The test device for oxygen transmission rate according to claim 1, further comprising at least one exhaust pipe communicating with the test chamber to directly discharge the gas in the lower chamber of the test chamber.
The oxygen transmission rate testing device according to claim 1, further comprising an oxygen inlet line, each of which is in communication with the upper cavity of the test cavity to send oxygen;

Or / and, further comprising a carrier gas pipeline, each carrier gas pipeline is in communication with the lower cavity of the test cavity, and a carrier gas is sent in;

Further, the sensor assembly is directly communicated with a carrier gas pipeline through a gas path.
The oxygen transmission rate testing device according to claim 1, wherein a control valve is provided on the connecting pipeline.
An oxygen transmission rate test system, comprising: the test device according to any one of claims 1 to 8 and a data processor, wherein the data processor is connected to each oxygen sensor and receives its detection data According to the data of each oxygen sensor, the test results are obtained.
An oxygen transmission rate test method is characterized by including the following steps:

1) The test gas flows into the upper cavity: oxygen enters the upper cavity of each test cavity;

2), the lower cavity is purged by the carrier gas: the carrier gas passes through the lower cavity of each test cavity;

3) Obtain the zero value: start the test, introduce the lower chamber gas into the atmosphere, and select an oxygen sensor whose range matches the oxygen transmission amount. At this time, the oxygen concentration read by the oxygen sensor is the zero line oxygen concentration value z, which will be stable. The subsequent z value is recorded as the zero oxygen concentration;

4) Measure the oxygen concentration of the sample penetration: Introduce the zero point gas path to the atmosphere, and introduce the gas in the lower chamber to the corresponding oxygen sensor. At this time, the oxygen concentration read by the oxygen sensor is that the sample between the upper and lower chambers penetrates. The oxygen concentration value a, the value of a when the recording is stable is recorded as the oxygen concentration of the sample, and the difference between the oxygen concentration value a and the zero oxygen concentration z is the oxygen concentration penetrated by the sample.
The method for testing the oxygen transmission rate according to claim 10, wherein the first oxygen sensor with a larger measurement range is selected without knowing the oxygen transmission rate of the sample, and the zero oxygen concentration is tested, and then the penetration is measured. Oxygen concentration, if the measured oxygen concentration value a of the test cavity is greater than the maximum range of the second oxygen sensor with a smaller range, continue to use the first oxygen sensor for measurement;

If it is found that the oxygen concentration value a in the test chamber is within the measurement range of the second oxygen sensor, the gas is introduced into the second oxygen sensor and the above test process is repeated. Both the oxygen concentration value a and the zero oxygen concentration z should be determined by the smaller range. Dioxin sensor.