A gas analysis sensor

Abstract

The application discloses a gas analysis sensor, which comprises a sensor circuit, a measuring element and a connecting assembly connecting the sensor circuit and the measuring element, wherein the measuring element comprises a shell, a copper sleeve, a partition plate and a resistance wire; the copper sleeve is arranged inside the shell; a vertical air inlet and a circular and vertical air outlet are arranged on the shell; the partition plate is arranged inside the copper sleeve and divides the inner cavity of the copper sleeve into two areas, namely a detection cavity and a reference cavity; the resistance wire is evenly distributed in the detection cavity and the reference cavity; a transversely arranged strip-shaped through hole is arranged on one side of the copper sleeve facing the measured gas; and a circular hole is arranged on the side of the copper sleeve away from the measured gas; in the application, the transversely arranged strip-shaped through hole is arranged on the side of the copper sleeve facing the measured gas, and the circular hole is arranged on the side of the copper sleeve away from the measured gas, so that the gas flux entering the sensor is the same, thereby ensuring the stability and accuracy of the sensor.

Description

Technical Field

[0001] This invention relates to the field of sensor technology, and in particular to a gas analysis sensor. Background Technology

[0002] In the 21st century, with rapid economic development, various sectors are continuously utilizing raw materials to produce resources to meet human needs. Heavy gases are commonly used as raw materials in heavy industries such as nuclear power and petrochemicals. However, heavy gases used as industrial raw materials are usually not pure and contain light impurities. Heavy gases whose purity does not meet industrial requirements not only affect the quality of the products produced but also easily pose safety hazards. Therefore, measuring the percentage of light impurities in heavy gases and detecting their purity is essential to ensuring product quality and eliminating safety risks.

[0003] Light impurity gas analysis and protection sensors are commonly used to measure the percentage content of light impurity gases in heavy gases in practical engineering. The principle is that the gas to be analyzed flows through the measuring chamber and the compensation chamber respectively. In the chamber, heat exchange occurs with the hot wire, causing the temperature of the hot wire to change, resulting in a change in resistance, which in turn generates a change in electrical signal. The electrical signal is detected to analyze the percentage content of light gases.

[0004] Existing gas analysis sensors, such as the one described in patent number CN201420636164.9, provide gas pressure detection and a mechanism to protect the thermal conductivity gas sensor when the gas pressure rises to a certain level. However, the stability and accuracy of the sensor are still affected by variations in gas flux. Summary of the Invention

[0005] The purpose of this invention is to provide a gas analysis sensor that solves the problem that existing sensors suffer from instability and accuracy due to variations in gas flux.

[0006] This invention is implemented as follows: a gas analysis sensor includes a sensor circuit, a measuring element, and a connecting assembly connecting the sensor circuit and the measuring element. The measuring element includes a housing, a copper sleeve, a partition, and a resistance wire. The copper sleeve is placed inside the housing. The housing has a vertical air inlet and a circular air outlet arranged vertically. The partition is placed inside the copper sleeve and divides the inner cavity of the copper sleeve into two regions, namely a detection chamber and a reference chamber. The resistance wire is equally distributed in the detection chamber and the reference chamber. The copper sleeve has a horizontally arranged strip-shaped through hole on the side facing the gas to be measured and a circular hole on the side away from the gas to be measured.

[0007] The gas to be analyzed flows through the sensor's measurement chamber and reference chamber, respectively. The percentage content of the light gas is measured by the change in heat carried away by the introduced gas from the resistance wire. A transverse strip-shaped through-hole is provided on the side facing the gas to be analyzed, while a round hole is provided on the side facing away from the gas to be analyzed, ensuring that the gas flow into the sensor is the same, thereby guaranteeing the stability and accuracy of the sensor.

[0008] A further technical solution of the present invention is: the cavity connected to the incoming flow channel is a detection cavity, and the cavity connected to the outgoing flow channel is a reference cavity.

[0009] A further technical solution of the present invention is: the strip-shaped through holes are multiple and uniformly arranged, the total area of ​​the strip-shaped through holes is the area of ​​the incoming flow channel, the circular holes are multiple and uniformly arranged, and the total area of ​​the circular holes is the area of ​​the outgoing flow channel.

[0010] The square through holes are all the same size and are evenly distributed on the copper sleeve.

[0011] A further technical solution of the present invention is that the area ratio of the incoming flow channel to the outgoing flow channel is (50-80):1.

[0012] The error signal, beneficial signal, and response time are determined by the sensor's structure. The ratio of error signal to beneficial signal is related to the ratio of the inflow and outflow channels of the copper sleeve. When the ratio of the inflow channel area to the outflow channel area of ​​the copper sleeve is between 50:1 and 80:1, the error signal can be lower than the threshold voltage ±0.5V, the beneficial signal can be greater than 3.2V, and the response time can be less than 1s.

[0013] The ratio of the inflow channel area to the outflow channel area is (50-80):1, which results in different exchange rates between the gas medium and the gas being analyzed in the two chambers. This also causes a difference in the equilibrium time between the content of light impurities in the working chamber and the compensation chamber and their content in the gas medium being analyzed. This minimizes the impact of unstable factors such as pressure changes and temperature fluctuations of the gas being analyzed, as well as fluctuations in the power supply voltage.

[0014] A further technical solution of the present invention is: the measuring element further includes a membrane tube, a nickel mesh, and a baffle structure, the membrane tube is sleeved on the outside of the copper sleeve, the nickel mesh is placed on the outside of the membrane tube, and the baffle structure is placed between the copper sleeve and the membrane tube.

[0015] The membrane tube and the bottom of the nickel mesh are fixed to the base plate. The analyzed medium passes through the multilayer nickel mesh, the membrane tube, and the wall holes on the copper sleeve to reach the thermistor for heat exchange, and outputs a measurement signal.

[0016] A further technical solution of the present invention is: the baffle structure includes a body and a baffle, the baffle is inclined at an angle α on the body and the surface of the baffle is arc-shaped.

[0017] The baffle is inclined at an angle α on the main body, and its surface is arc-shaped, serving to block soluble gel and improve the sensor's measurement accuracy. Furthermore, the upper and lower baffles are inclined in opposite directions. When no baffle is installed inside the nickel mesh, the mesh can only effectively block large solid particles, but it cannot effectively block soluble gel particles. This is because, without external interference, soluble gel particles move randomly, and the probability of them moving from the outside to the inside of the nickel mesh is roughly the same as the probability of them moving from the inside to the outside. However, when the sensor is working, the soluble gel particles, carried by the test airflow, move from the outside to the inside of the nickel mesh. A large number of soluble gel particles enter the sensor's core components, affecting the sensor's measurement accuracy and sensitivity, accelerating contamination and aging of the core components, and reducing the sensor's lifespan. When this type of baffle is installed inside the nickel mesh, the probability of soluble gel particles being transported from the outside to the inside of the nickel mesh is much smaller than the probability of them being transported from the inside to the outside. This effectively blocks the soluble gel particles, reducing the probability of them entering the core components of the sensor from 46% to less than 5%. This solves the problems caused by soluble gel particles entering the core components of the sensor. In addition, the baffle structure can also reduce the impact of incoming flow, which is conducive to obtaining a stable test signal and improving the service life of the sensor.

[0018] A further technical solution of the present invention is that the baffle is arranged along the outer periphery of the body, and the upper and lower baffles are inclined in opposite directions.

[0019] A further technical solution of the present invention is that α is 10-30°, and the central angle of the arc is 20-60°.

[0020] A further technical solution of the present invention is that the aperture of the nickel mesh is 250-300 mesh.

[0021] It can filter out large solid particles such as welding slag, protecting the sensor's measuring elements.

[0022] A further technical solution of the present invention is that the membrane tube is made by sintering nickel powder onto a mesh tube.

[0023] A further technical solution of the present invention is that the resistance wire is formed by spirally winding metal wire.

[0024] Compared to straight monofilaments, wound wires use longer wires and occupy less space. Thus, within the same effective sensor space and under the same temperature changes, the signal generated by wound wires is significantly greater than that of straight wires, solving the requirement for large sampling signals in limited space and improving product sensitivity.

[0025] A further technical solution of the present invention is: the partition is a perforated partition to prevent the cylinder cavity from being affected by aerodynamic interference; the partition is covered with a nickel wire mesh to capture aerosols.

[0026] The sensor in this invention is suitable for use in equipment systems where the absolute pressure of the tested medium is 0.13-12 kPa, the ambient air temperature is 10-35°C, and the relative humidity is below 80%.

[0027] The beneficial effects of this invention are as follows: The gas to be analyzed flows through the sensor's measurement chamber and compensation chamber respectively, and the percentage content of light gases is measured by carrying away the heat change of the resistance wire through the introduced gas. This invention has a transverse strip-shaped through-hole on the side facing the gas to be measured, and a round hole on the side away from the gas to be measured, ensuring that the gas flow into the sensor is the same, thereby guaranteeing the stability and accuracy of the sensor. It features high detection reliability, reduced testing costs for light impurity gases, and improved reliability and efficiency in safe production.

[0028] The baffle is set inside the nickel mesh at an angle α and has an arc-shaped surface. This solves the problems of interference from large particles, aerosols, and some interfering gases in the measurement environment, which affect the normal operation of the sensor and reduce its lifespan, while improving the measurement accuracy of the sensor.

[0029] The resistance wire in this invention is made of metal wire wound in a spiral, with a longer wire occupying less space. Thus, within the same effective sensor space and under the same temperature change conditions, the signal generated by the spiral wire is significantly greater than that of the straight wire, solving the requirement for a large sampling signal in a limited space and improving the product's sensitivity. Attached Figure Description

[0030] Figure 1a This is a partial cross-sectional view of a gas analysis protection sensor according to the present invention;

[0031] Figure 1b This is a schematic diagram of the internal structure of the measuring element of a gas analysis protection sensor according to the present invention;

[0032] Figure 2a This is a schematic diagram of the structure with the copper sleeve facing the gas being measured.

[0033] Figure 2b This is a schematic diagram of the structure of the copper sleeve facing away from the gas being measured;

[0034] Figure 3 This is a schematic diagram of a bridge circuit for a sensor detection circuit.

[0035] Figure 4 The output diagram for detecting accident signals using the sensor provided in the specific implementation method;

[0036] Figure 5 This is a schematic diagram of the baffle structure;

[0037] Figure 6 This is a schematic diagram of the measuring element;

[0038] Figure 7 This is a schematic diagram of the structure of the outer shell provided by the present invention, which has an air outlet on one side.

[0039] Figure reference numerals: 1: Resistance wire; 2: Separator; 3: Potentiometer; 4: Adjustment circuit board; 5: Power circuit board; 6: Screw sleeve; 7: Upper fixing plate; 8: Aviation plug; 9: Outer cover; 10: Intermediate plate; 11: Fixing base; 12: Flange; 13: Copper sleeve; 14: Nickel mesh; 15: Outer shell; 16: Strip-shaped through hole; 17: Round hole; 18: Baffle plate; 19: Membrane tube; 20: Connecting cover. Detailed Implementation

[0040] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0041] It should be noted that the structures, proportions, sizes, etc., illustrated in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and to facilitate understanding and reading. They are not intended to limit the scope of the invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of the invention, should still fall within the scope of the technical content disclosed herein. Furthermore, the terms "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity and not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention.

[0042] Example 1:

[0043] Figure 1-7 shows a gas analysis sensor, including a sensor circuit, a measuring element, and a connecting assembly connecting the sensor circuit and the measuring element. The measuring element includes a housing 15, a copper sleeve 13, a partition 2, and a resistance wire 1. The copper sleeve 13 is placed inside the housing 15. The housing 15 has a vertical air inlet and a circular air outlet arranged vertically. The partition 2 is placed inside the copper sleeve 13 and divides the inner cavity of the copper sleeve 13 into two regions, namely a detection chamber and a reference chamber. The resistance wire 1 is evenly distributed in the detection chamber and the reference chamber. The copper sleeve 13 has a horizontally arranged strip-shaped through hole 16 on the side facing the gas to be measured and a circular hole 17 on the side away from the gas to be measured.

[0044] In this embodiment, the sensor circuit includes a potential regulator 3, an adjustment circuit board 4 electrically connected to the potential regulator 3, a power supply circuit board 5 that supplies power to the sensor circuit, a screw sleeve 6 that connects the upper fixing plate and the circuit board, an aviation plug 8, an upper fixing plate 7 for mounting the sensor, and an outer cover 9 that protects the circuit components; the connection assembly includes an intermediate plate 10, a fixing seat 11, and a flange 12 connected in sequence from top to bottom, and the connection assembly is used to connect the sensor circuit and the measuring element.

[0045] In this embodiment, the cavity connected to the incoming flow channel is the detection cavity, and the cavity connected to the outgoing flow channel is the reference cavity.

[0046] In this embodiment, there are multiple strip-shaped through holes 16 that are evenly arranged, and the total area of ​​the strip-shaped through holes 16 is the area of ​​the incoming flow channel. There are multiple circular holes 17 that are evenly arranged, and the total area of ​​the circular holes 17 is the area of ​​the outgoing flow channel.

[0047] In this embodiment, the square through holes are all the same size and evenly distributed on the copper sleeve.

[0048] In this embodiment, the ratio of the incoming flow channel area to the outgoing flow channel area is 50:1. The error signal voltage is 0.3V, the beneficial signal voltage is 3.2V, and the response time is 0.95s.

[0049] In this embodiment, the measuring element further includes a membrane tube 19, a nickel mesh 14, and a baffle structure. The membrane tube is sleeved on the outside of the copper sleeve 13, the nickel mesh 14 is placed on the outside of the membrane tube 19, and the baffle structure is placed between the copper sleeve 13 and the membrane tube 19.

[0050] In this embodiment, the nickel mesh is multi-layered, and the membrane tube and the bottom of the nickel mesh are fixed to the base plate. The analyzed medium passes through the multi-layered nickel mesh, the membrane tube, and the wall holes on the copper sleeve to reach the thermistor for heat exchange, and outputs a measurement signal.

[0051] In this embodiment, the baffle structure includes a body and a baffle 18, the baffle 18 is inclined at an angle α on the body and the surface of the baffle 18 is arc-shaped.

[0052] The baffle 18 is inclined at an angle α on the main body, and its surface is arc-shaped, serving to block soluble gel and improve the sensor's measurement accuracy. Furthermore, the upper and lower baffles are inclined in opposite directions. When no baffle is installed inside the nickel mesh, the mesh can only effectively block large solid particles, but it cannot effectively block soluble gel particles. This is because, without external interference, soluble gel particles move randomly, and the probability of them moving from the outside to the inside of the nickel mesh is roughly the same as the probability of them moving from the inside to the outside. However, when the sensor is working, the soluble gel particles, carried by the test airflow, move from the outside to the inside of the nickel mesh. A large number of soluble gel particles enter the sensor's core components, affecting the sensor's measurement accuracy and sensitivity, accelerating contamination and aging of the core components, and reducing the sensor's lifespan. When this type of baffle is installed inside the nickel mesh, the probability of soluble gel particles being transported from the outside to the inside of the nickel mesh is much smaller than the probability of them being transported from the inside to the outside. This effectively blocks the soluble gel particles, reducing the probability of them entering the core components of the sensor from 46% to less than 5%. This solves the problems caused by soluble gel particles entering the core components of the sensor. In addition, the baffle structure can also reduce the impact of incoming flow, which is conducive to obtaining a stable test signal and improving the service life of the sensor.

[0053] In this embodiment, the baffle 18 is arranged along the outer periphery of the body, and the upper and lower baffles 18 are inclined in opposite directions.

[0054] In this embodiment, α is 10-30°, and the central angle of the arc is 20-60°.

[0055] In this embodiment, the aperture of the nickel mesh 14 is 250-300 mesh.

[0056] It can filter out large solid particles such as welding slag, protecting the sensor's measuring elements.

[0057] In this embodiment, the membrane tube 19 is made by sintering nickel powder onto a mesh tube.

[0058] In this embodiment, the membrane tube has a thickness of 0.7 mm and a diameter of 12 mm.

[0059] In this embodiment, the resistance wire 1 is formed by spirally winding metal wire.

[0060] In this embodiment, the resistance wire is made of a metal wire with a diameter of 0.05 mm wound together, and the resistance of a single resistance wire is 32.5 ± 0.1 Ω at an ambient air temperature of 0 ± 0.5 ℃.

[0061] In this embodiment, each sensor has eight spirally wound metal wires. Compared to straight single wires, the spirally wound wires are longer and occupy less space. Thus, within the same effective sensor space and under the same temperature change conditions, the signal generated by the spirally wound wires is significantly greater than that of the straight wires, solving the requirement of large sampling signals in a limited space and improving the sensitivity of the product.

[0062] As another embodiment, using mandrels of different diameters to wind the resistance wire has different effects on sensitivity; for example, when using a 1mm mandrel to wind the resistance wire to a length of 30mm, the sensor sensitivity is increased by 45 times compared to when the resistance wire is straight. When the system suddenly leaks in light impurity gas, most of it enters the detection chamber through the inflow channel, changing the heat dissipation state inside the detection chamber, thereby changing the resistance value of the thermistor wire inside the detection chamber, and increasing the bridge output signal.

[0063] In this embodiment, the partition 2 is a perforated partition to prevent the cylinder cavity from being affected by aerodynamic interference; the partition 2 is covered with a nickel wire mesh to capture aerosols.

[0064] The working principle of the gas analysis sensor in this embodiment:

[0065] The sensor circuit consists of a detection circuit, an amplification circuit, and a stabilization circuit. The detection circuit is a DC unbalanced bridge circuit, which converts the measured impurity volume content into an electrical signal using a thermal measurement method, and is the basis of the sensor's operation. Four thermistors R5-R8 are connected in the bridge circuit and are placed within the analyzed medium. Its circuit diagram is shown in Figure 3 (powered by DC 15V, output in mV form). Figure 3 In the diagram, R1 = R3: correction resistor, R2: zero-position corrector, R4: sensitivity corrector, R5 = R8: working arm, and R6 = R7: compensation arm.

[0066] Variable resistor R2 serves as a zero-point corrector, and R4 as a sensitivity corrector. The four thermistor elements, R5-R8, in the bridge circuit are made into resistance wires and fixed in two cavities respectively. Figure 1b Its location can be seen in the image. This thermistor has uniform volt-ampere characteristics and uniform heat dissipation. Each resistor consists of two resistance wires with a resistance of 32.5 (±0.1) ohms (0℃).

[0067] In this embodiment, the thermistor is composed of two series-connected resistance wires wound together with nickel wires of 0.05 mm in diameter. The resistance of one resistance wire is (32.5 ± 0.1) ohms at an ambient air temperature of (0 ± 0.5) °C.

[0068] Printed circuit labels (such as) Figure 3 As shown, it is equipped with calibrators R2 and R4, as well as DC resistors R1 and R3 for expanding the calibration range, all of which are fixed on the frame and covered by a connection cover 20. The upper part of the connection cover 20 is provided with a connector pull plug.

[0069] During time intervals when the light impurity content in the two chambers is uneven, a pulsed output signal will be generated. The effect of changes in the volumetric light impurity content in the analyzed medium on the output signal when the load resistance RH = 300Ω and RH = 1000Ω is as follows: Figure 4 As shown.

[0070] Specifically, the output signal increases from 10% to 80% of its peak value within the following timeframes: when the pressure of the measured medium is 0.13–1.8 kPa (0.1–6 mmHg), the increase time does not exceed 5.0 s; when the pressure of the measured medium is 0.8–4.0 kPa (6–30 mmHg), the increase time does not exceed 7.0 s; and when the pressure of the measured medium is 4.0–6.0 kPa (30–45 mmHg), the increase time does not exceed 10.0 s.

[0071] Example 2:

[0072] The difference from Example 1 is that, in this example, the ratio of the incoming flow channel area to the outgoing flow channel area is 70:1. The error signal voltage is 0.38V, the beneficial signal voltage is 4.3V, and the response time is 0.5s.

[0073] Example 3:

[0074] The difference from Example 1 is that, in this example, the ratio of the incoming flow channel area to the outgoing flow channel area is 80:1. The error signal voltage is 0.5V, the beneficial signal voltage is 5.6V, and the response time is 0.7s.

[0075] Comparative Example 1:

[0076] The difference from Example 1 is that, in this example, the ratio of the incoming flow channel area to the outgoing flow channel area is 1:1. The error signal voltage is 6mV, the beneficial signal voltage is 200mV, and the response time is 3.8s.

[0077] Comparative Example 2:

[0078] The difference from Example 1 is that, in this example, the ratio of the incoming flow channel area to the outgoing flow channel area is 95:1. The error signal voltage is 0.56V, the beneficial signal voltage is 6.4V, and the response time is 2.6s.

[0079] The error signal, beneficial signal, and reaction time are determined by the structure of the sensor itself. According to the research of this invention, the ratio of error signal to beneficial signal is related to the ratio of the area of ​​the copper sleeve inlet and outlet channels. Specific embodiments with different ratios of copper sleeve inlet and outlet channels are shown in Table 1.

[0080] Table 1. Relationship between error signal, beneficial signal, and reaction time with the ratio of the inlet and outlet flow areas of the copper bushing.

[0081]

[0082]

[0083] When the ratio of the copper bushing inlet channel area to the copper bushing outlet channel area is between 50:1 and 80:1, the error signal is kept below the threshold voltage by ±0.5V, the beneficial signal is greater than 3.2V, and the response time is less than 1s. At this ratio, the error signal voltage will not exceed the threshold voltage, preventing false alarms; the generated beneficial signal is larger and easier to detect, significantly improving the stability and accuracy of sensor detection. When the ratio of the copper bushing inlet channel area to the copper bushing outlet channel area is 70:1, both the error signal and the beneficial signal greatly meet the relevant measurement requirements, and the response time is only 0.5s. When the ratio is less than 50:1, the beneficial signal is too small, which is not conducive to the acquisition of beneficial signals for detecting light impurities, and the response time is longer. When the ratio is greater than 80:1, the response time is longer, the error signal is too large, exceeding the sensor's alarm threshold voltage, causing false alarms and affecting normal and safe production.

[0084] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A gas analysis sensor, comprising a sensor circuit, a measuring element, and a connecting assembly connecting the sensor circuit and the measuring element, characterized in that: The measuring element includes a housing (15), a copper sleeve (13), a partition (2), and a resistance wire (1). The copper sleeve (13) is placed inside the housing (15). The housing (15) has a vertical air inlet and a circular air outlet arranged vertically. The partition (2) is placed inside the copper sleeve (13) and divides the inner cavity of the copper sleeve (13) into two regions, namely a detection cavity and a reference cavity. The resistance wire (1) is placed in the detection cavity and the reference cavity. The cavity is evenly distributed. The copper sleeve (13) has horizontally arranged strip-shaped through holes (16) on the side facing the gas to be measured, and round holes (17) on the side away from the gas to be measured. There are multiple strip-shaped through holes (16) evenly arranged, and the total area of ​​the strip-shaped through holes (16) is the area of ​​the incoming flow channel. There are multiple round holes (17) evenly arranged, and the total area of ​​the round holes (17) is the area of ​​the outgoing flow channel. The area ratio of the incoming flow channel to the outgoing flow channel is (50-80):

1.

2. A gas analysis sensor according to claim 1, characterized in that, The measuring element also includes a membrane tube (19), a nickel mesh (14), and a baffle structure. The membrane tube is sleeved outside the copper sleeve (13), the nickel mesh (14) is placed outside the membrane tube (19), and the baffle structure is placed between the copper sleeve (13) and the membrane tube (19).

3. A gas analysis sensor according to claim 2, characterized in that, The baffle structure includes a body and a baffle (18), the baffle (18) is inclined at an angle α on the body and the surface of the baffle (18) is arc-shaped.

4. A gas analysis sensor according to claim 3, characterized in that, The baffle (18) is arranged along the outer periphery of the body, and the upper and lower baffles (18) are inclined in opposite directions.

5. A gas analysis sensor according to claim 3, characterized in that, The α is 10-30°, the arc radius is 20-60°, and the aperture of the nickel mesh (14) is 250-300 mesh.

6. A gas analysis sensor according to claim 2, characterized in that, The membrane tube (19) is made by sintering nickel powder onto a mesh tube.

7. A gas analysis sensor according to claim 1, characterized in that, The resistance wire (1) is made of metal wire spirally wound.

8. A gas analysis sensor according to claim 1, characterized in that, The partition (2) is a perforated partition, and the partition (2) is covered with nickel wire mesh.

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