Electromagnetic induction type paramagnetic oxygen sensor

Abstract

According to the electromagnetic induction type paramagnetic oxygen sensor, a power source is turned on, and detection gas enters a detection air gap through a fan in the gas flowing direction and is exhausted through an exhaust port. Primary current input by the primary winding is sine alternating current, the secondary reference winding and the secondary detection winding induce secondary reference electromotive force and secondary detection electromotive force, and in the absence of oxygen, the secondary reference electromotive force and the secondary detection electromotive force are equal in magnitude and opposite in direction, and output current is zero. Under the condition that oxygen exists, the secondary reference electromotive force is not changed, paramagnetic gas oxygen enters a detection air gap, the magnetic flux of the detection air gap is inevitably increased, the magnetic flux in a detection iron core is inevitably larger than the magnetic flux in a reference iron core, the secondary detection electromotive force is increased and larger than the secondary reference electromotive force, and output current is generated. Along with the increase of the oxygen content, the output current is correspondingly increased, so that the oxygen content in the to-be-detected gas is detected. The technology is mature, the structure is simple, and vibration, corrosion and oxidation are prevented.

Description

(1) Technical Field

[0001] The present invention relates to an oxygen sensor, particularly an electromagnetic induction paramagnetic oxygen sensor that utilizes the paramagnetic property of oxygen for detection. (2) Background Art

[0002] According to the introduction of Delta (Beijing) Technology Co., Ltd., paramagnetic oxygen sensors are divided into two types: thermal magnetic wind and optical mechanical magnetic force.

[0003] Thermal magnetic wind paramagnetic oxygen sensor: A magnetic wind paramagnetic oxygen sensor relies on the response principle of paramagnetic gases such as oxygen to a magnetic field. In the magnetic wind method, a gas sample is introduced into a chamber containing a heating wire surrounded by a magnetic field. Oxygen molecules in the sample gas are attracted to the heating wire with a strong magnetic field. When the oxygen molecules reach the heating wire, they are heated and lose their magnetic susceptibility. This causes them to rise upward due to the colder gas entering from below, thus generating a phenomenon called "magnetic wind". The intensity of this magnetic wind is proportional to the oxygen concentration in the sample gas.

[0004] Mechanical optical magnetic force method paramagnetic oxygen sensor: The mechanical optical magnetic force method measures the sensitivity of a gas sample to a magnetic field. A dumbbell-shaped object with a low magnetic susceptibility is suspended in a magnetic field. When a sample gas containing oxygen is introduced near the dumbbell, oxygen molecules are attracted to the point with a strong magnetic field intensity, causing the dumbbell to deflect slightly in the opposite direction. This deflection of the dumbbell is detected by a light source and a reflector connected to a suspension cable. The generated signal is used to generate a current proportional to the oxygen concentration in the sample gas. Compared with other methods, the optical mechanical magnetic force method has a lower resistance to mechanical interference.

[0005] The related patents of paramagnetic oxygen sensors are as follows:

[0006] Patent Application No.: CN 200980146271.5, titled "Compact Paramagnetic Oxygen Sensor". This patent discloses a device for measuring the magnetic susceptibility of a gas mixture, including: a gas sample chamber adapted to accommodate the gas mixture and a test body that can be rotatably suspended in the gas sample chamber; a device for generating a non-uniform magnetic field in the gas sample chamber; a device for detecting the rotational movement of the test body, which includes a compact optical system, the optical system including a light source and a photodetector arranged to detect the optical signal indication of the rotational movement; and an actuation system arranged to keep the test body substantially at the electrical zero position determined by the optical system, where the optical elements include at least one photodetector positioned on either side of a plane perpendicular to the mirror and parallel to the rotational axis of the test body, with a light source positioned in the plane. To improve performance, the optical elements are positioned in front of the light source or the detector to modify the characteristics of the light emitted by the light source or received by the photodetector.

[0007] The magnetic wind paramagnetic oxygen sensor needs to heat oxygen with an electric heating wire, and the sensor needs to be corrosion-proof and oxidation-proof, which is a challenge to the lifespan of the sensor. The mechanical optical magnetic method paramagnetic oxygen sensor has a low resistance to mechanical interference.

[0008] Therefore, it is necessary to design an electromagnetic induction type paramagnetic oxygen sensor that is corrosion-free, oxidation-free, and resistant to mechanical interference. (III) Summary of the Invention

[0009] The content of the present invention is to design an electromagnetic induction type paramagnetic oxygen sensor that is corrosion-free, oxidation-free, and resistant to mechanical interference.

[0010] The object of the present invention is achieved as follows: The electromagnetic induction type paramagnetic oxygen sensor has a housing, a fan, a circuit board, a lower iron core, an upper iron core, a primary winding, a secondary reference winding, a secondary detection winding, a gas flow direction, a wire; an exhaust port, a partition board, a gas blocking board; a connector; a primary iron core, a reference iron core, a detection iron core, a reference air gap, a detection air gap; a primary magnetic head, a reference magnetic head, a detection magnetic head, an adjustment screw; (61) a primary current, a secondary reference electromotive force, a secondary detection electromotive force, a secondary output current.

[0011] The primary current is a sinusoidal alternating current. The lower iron core is a mountain-shaped iron core, with a cylindrical shape in the middle as the primary iron core, a conical shape on the left as the reference iron core, and a blade shape on the right as the detection iron core. The upper iron core is an inverted mountain-shaped iron core, with a cylindrical shape in the middle as the primary magnetic head, a blade shape on the left as the reference magnetic head, and a blade shape on the right as the detection magnetic head. The reference magnetic head is fixed on the upper iron core. The detection magnetic head can slide on the upper iron core, and the up and down position is adjusted by the adjustment screw to change the detection air gap. The lower iron core and the upper iron core are installed opposite to each other, with the primary iron core and the primary magnetic head in the middle aligned, the blade head of the reference iron core on the left aligned with the blade head of the reference magnetic head; the blade head of the detection iron core on the right aligned with the blade head of the detection magnetic head.

[0012] The housing has an exhaust port, a partition board, and a gas blocking board. The partition board isolates the connection between the secondary reference winding and the outside air, and the left side of the partition board is filled with nitrogen. The gas blocking board prevents the detection gas from directly discharging without passing through the detection air gap.

[0013] First, perform calibration. Turn on the power, and the calibration gas nitrogen enters the detection air gap through the fan along the gas flow direction and is discharged from the exhaust port. Observe the output current and adjust the adjustment screw, that is, adjust the detection air gap, so that the output current is zero.

[0014] The detected gas enters the detection air gap along the gas flow direction through the fan and is discharged from the exhaust port. A primary current of sinusoidal alternating current is input to the primary winding. According to the transformer principle, the secondary reference winding and the secondary detection winding will induce a secondary reference electromotive force and a secondary detection electromotive force. In the absence of oxygen, the magnitudes of the secondary reference electromotive force and the secondary detection electromotive force are equal and opposite in direction, and the output current is zero.

[0015] In the presence of oxygen, the secondary reference electromotive force remains unchanged. When the paramagnetic gas oxygen enters the detection air gap, the magnetic constant of the detection air gap will inevitably increase, and the magnetic flux in the detection iron core must be greater than that in the reference iron core, causing the secondary detection electromotive force to increase and become greater than the secondary reference electromotive force, generating an output current. As the oxygen content increases, the output current increases correspondingly. Thus, the oxygen content in the gas to be detected is detected. (4) Description of the Drawings

[0016] The specific structure of the present invention is given by the following embodiments and their drawings:

[0017] Attached Figure 1 is the axonometric view of the electromagnetic induction type paramagnetic oxygen sensor of the present invention. Attached Figure 2 is the internal axonometric view of the electromagnetic induction type paramagnetic oxygen sensor of the present invention. Attached Figure 3 is the sectional view taken along the A-A section of the electromagnetic induction type paramagnetic oxygen sensor of the present invention. Attached Figure 4 is the sectional view taken along the B-B section of the electromagnetic induction type paramagnetic oxygen sensor of the present invention. Attached Figure 5 is the induction principle diagram of the electromagnetic induction type paramagnetic oxygen sensor of the present invention.

[0018] Among them, (1) housing, (2) fan, (3) circuit board, (4) lower iron core, (5) upper iron core, (6) primary winding, (7) secondary reference winding, (8) secondary detection winding, (9) gas flow direction, (10) wire; (11) exhaust port, (12) partition board, (13) gas blocking board; (31) connector; (41) primary iron core, (42) reference iron core, (43) detection iron core, (44) reference air gap, (45) detection air gap; (51) primary magnetic head, (52) reference magnetic head, (53) detection magnetic head, (54) adjustment screw; (61) primary current, (71) secondary reference electromotive force, (81) secondary detection electromotive force, (82) secondary output current.

[0019] Referring to Attached Figure 2 and Attached Figure 3 and Attached Figure 5: The primary current (6) is a sinusoidal alternating current. The lower iron core (4) is a mountain-shaped iron core. The middle cylindrical part is the primary iron core (41), the left conical part is the reference iron core (42), and the right blade-shaped part is the detection iron core (43). The upper iron core (5) is an inverted mountain-shaped iron core. The middle cylindrical part is the primary magnetic head (51), the left blade-shaped part is the reference magnetic head (52), and the right blade-shaped part is the detection magnetic head (53). The reference magnetic head (52) is fixed on the upper iron core (5). The detection magnetic head (53) can slide on the upper iron core (5), and is adjusted up and down by adjusting the screw (54) to adjust the detection air gap (45). The lower iron core (4) and the upper iron core (5) are installed opposite to each other. The middle primary iron core (41) and the primary magnetic head (51) are aligned. The blade head of the left reference iron core (42) is aligned with the blade head of the reference magnetic head (52); the blade head of the right detection iron core (43) is aligned with the blade head of the detection magnetic head (53).

[0020] The housing (1) has an exhaust port (11), a partition plate (12), and a gas blocking plate (13). The partition plate (12) isolates the communication between the secondary reference winding (7) and the outside air. The gas blocking plate (13) prevents the detection gas from directly discharging without passing through the detection air gap (45). (V) Specific implementation mode

[0021] Manufacture each component of the electromagnetic induction paramagnetic oxygen sensor of the present invention according to the attached drawings. Assemble to form the electromagnetic induction paramagnetic oxygen sensor of the present invention.

[0022] Refer to the attached Figure 5 , the left side of the partition plate (12) is filled with nitrogen, the reference air gap (44) is filled with nitrogen, and is isolated from the outside. First, perform calibration. Turn on the power supply. The calibration gas nitrogen enters the detection air gap (45) along the gas flow direction (9) through the fan (2) and is discharged from the exhaust port (11). Observe the output current (82), and adjust the adjustment screw (54), that is, adjust the detection air gap (45), so that the output current (82) is zero.

[0023] The working process of the present invention is as follows:

[0024] Turn on the power supply. The detection gas enters the detection air gap (45) along the gas flow direction (9) through the fan (2) and is discharged from the exhaust port (11). Input a primary current (61) of sinusoidal alternating current to the primary winding (6). According to the transformer principle, the secondary reference winding (7) and the secondary detection winding (8) will induce a secondary reference electromotive force (71) and a secondary detection electromotive force (81). In the absence of oxygen, the magnitudes of the secondary reference electromotive force (71) and the secondary detection electromotive force (81) are equal and the directions are opposite, and the output current (82) is zero.

[0025] In the presence of oxygen, the secondary reference electromotive force (71) remains unchanged. When the detection air gap (45) admits the paramagnetic gas oxygen, the magnetic constant of the detection air gap (45) will necessarily increase. The magnetic flux in the detection iron core (43) will necessarily be greater than that in the reference iron core (42), causing the secondary detection electromotive force (81) to increase and become greater than the secondary reference electromotive force (71), thereby generating an output current (82). As the oxygen content increases, the output current (82) increases correspondingly. In this way, the oxygen content in the gas to be detected is detected.

[0026] The present invention has the following characteristics:

[0027] 1. The electromagnetic induction type paramagnetic oxygen sensor has all the advantages of a paramagnetic oxygen sensor.

[0028] 2. The electromagnetic induction type paramagnetic oxygen sensor applies transformer technology, and the technology is mature.

[0029] 3. It has a simple structure, and is vibration-proof, corrosion-proof, and oxidation-proof.

Claims

1. An electromagnetic induction paramagnetic oxygen sensor, characterized in that Electromagnetic induction paramagnetic oxygen sensors are: Housing (1), fan (2), circuit board (3), lower iron core (4), upper iron core (5), primary winding (6), secondary reference winding (7), secondary detection winding (8), gas flow direction (9), wire (10); exhaust port (11), isolation plate (12), air blocking plate (13); connector (31); primary iron core (41), reference iron core (42), detection iron core (43), reference air gap (44), detection air gap (45); primary magnetic head (51), reference magnetic head (52), detection magnetic head (53), adjustment screw (54); primary current (61); secondary reference electromotive force (71); Secondary detection electromotive force (81), secondary output current (82); The primary current (6) is a sinusoidal alternating current; the lower iron core (4) is a mountain-shaped iron core, the middle cylindrical shape is a primary iron core (41), the left conical shape is a reference iron core (42), and the right blade-shaped shape is a detection iron core (43); the upper iron core (5) is an inverted mountain-shaped iron core, the middle cylindrical shape is a primary magnetic head (51), the left blade-shaped shape is a reference magnetic head (52), and the right blade-shaped shape is a detection magnetic head (53). The reference magnetic head (52) is fixed on the upper iron core (5); the detection magnetic head (53) can slide on the upper iron core (5) and can be adjusted up and down by adjusting screws (54) to adjust the detection air gap (45); the lower iron core (4) and the upper iron core (5) are relatively installed, the middle primary iron core (41) and the primary magnetic head (51) are aligned, the blade head of the left reference iron core (42) is aligned with the blade head of the reference magnetic head (52); the blade head of the right detection iron core (43) is aligned with the blade head of the detection magnetic head (53); The housing (1) comprises an exhaust port (11), an isolation plate (12), and an air blocking plate (13); the isolation plate (12) isolates the secondary reference winding (7) from being connected to the outside air, and the air blocking plate (13) prevents the detection gas from being directly discharged without passing through the detection air gap (45).

2. The electromagnetic induction paramagnetic oxygen sensor according to claim 1, characterized in that: The left side of the isolation plate (12) is filled with nitrogen, and the reference air gap (44) is filled with nitrogen to be isolated from the outside.

3. The electromagnetic induction paramagnetic oxygen sensor according to claim 1, characterized in that: The method for calibrating the electromagnetic induction paramagnetic oxygen sensor is as follows: turning on the power supply, allowing the calibration gas nitrogen to enter the detection air gap (45) along the gas flow direction (9) through the fan (2) and be discharged from the exhaust port (11); Observe the output current (82) and adjust the adjustment screw (54), that is, adjust the detection air gap (45), so that the output current (82) is zero.

4. The electromagnetic induction paramagnetic oxygen sensor according to claim 1, characterized in that: The oxygen detection process is as follows: turn on the power supply, and the detection gas enters the detection air gap (45) along the gas flow direction (9) through the fan (2) and is discharged from the exhaust port (11); the primary current (61) is input into the primary winding (6) as a sinusoidal alternating current. According to the transformer principle, the secondary reference winding (7) and the secondary detection winding (8) will induce a secondary reference electromotive force (71) and a secondary detection electromotive force (81). In the absence of oxygen, the secondary reference electromotive force (71) and the secondary detection electromotive force (81) are equal in magnitude and opposite in direction. , the output current (82) is zero; in the presence of oxygen, the secondary reference electromotive force (71) remains unchanged, and the paramagnetic gas oxygen enters the detection air gap (45), which will inevitably increase the magnetic constant of the detection air gap (45), and the magnetic flux in the detection iron core (43) will inevitably be greater than the magnetic flux in the reference iron core (42), so that the secondary detection electromotive force (81) increases and is greater than the secondary reference electromotive force (71), generating an output current (82); as the oxygen content increases, the output current (82) increases accordingly; thereby detecting the oxygen content in the gas to be detected.

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