JP5829149B2 - Abnormality diagnosis device and abnormality diagnosis method for differential pressure sensor - Google Patents

Description

  The present invention relates to an abnormality diagnosis device and an abnormality diagnosis method for a sealed liquid sealing type differential pressure sensor in which a pressure transmission medium is sealed as a sealed liquid.

  Conventionally, there are various types of differential pressure sensors. Among them, there is a sealed liquid sealing type differential pressure sensor in which a pressure transmission medium is sealed as a sealed liquid (for example, see Patent Document 1). . In this sealed liquid-sealed differential pressure sensor, an incompressible fluid such as silicone oil is used as a pressure transmission medium. FIG. 3 shows a cross-sectional view of a main part of an example of a conventional sealed liquid sealing type differential pressure sensor.

  In FIG. 3, reference numeral 1 denotes a metal body, which has a first space 1-2 and a second space 1-3 partitioned by a partition wall 1-1 as internal spaces. The partition wall 1-1 is provided with a through passage 1-4 that communicates the first space 1-2 and the second space 1-3. A first metal diaphragm (first pressure receiving diaphragm) 2-1 is provided in the opening 1-2a of the first space 1-2, and the opening 1-3a of the second space 1-3 is provided in the opening 1-3a. Is provided with a second metal diaphragm (second pressure receiving diaphragm) 2-2.

  Reference numeral 3 denotes a sensor chip, which is composed of a sensor diaphragm 3-1 and a pedestal 3-2. The sensor diaphragm 3-1 is made of silicon or the like, and the pedestal 3-2 is made of silicon or glass. The center portion of the sensor diaphragm 3-1 is thin, and a recess 3-1c is formed on the other surface 3-1b with respect to the one surface 3-1a, and the other of which the recess 3-1c is formed. One end surface 3-2a of the pedestal 3-2 is joined to the surface 3-1c side. The pedestal 3-2 has a cylindrical shape, and the communication passage 3- connected to the other surface 3-1b of the sensor diaphragm 3-1 by the hollow portion 3-2c and the concave portion 3-1c of the sensor diaphragm 3-1. 3 is formed.

  The sensor chip 3 has a communication passage 3-3 that communicates with the other surface 3-1b of the sensor diaphragm 3-1, such that one surface 3-1a of the sensor diaphragm 3-1 faces the first pressure receiving diaphragm 2-1. It is joined to the wall surface 1-1a of the partition wall 1-1 located on the first space 1-2 side so as to communicate with the through passage 1-4 of the partition wall 1-1. That is, the other end surface 3-2b of the pedestal 3-2 is connected to the wall surface 1- 1 of the partition wall 1-1 so that the hollow portion 3-2c of the pedestal 3-2 communicates with the through passage 1-4 of the partition wall 1-1. It is made to join to 1a. Hereinafter, a joint portion between the pedestal 3-2 and the partition wall 1-1 is referred to as a first joint portion 4-1, and a joint portion between the pedestal 3-2 and the sensor diaphragm 3-1 is referred to as a second joint portion 4-2. To do.

  The body 1 is sealed with a first pressure transmission medium 5-1 using the first space 1-2 as the first enclosure chamber 6-1. In addition, the communication path 3-3 that communicates with the second space 1-3, the through passage 1-4 of the partition wall 1-1, and the other surface 3-1b of the sensor diaphragm 3-1 is defined as a second enclosure chamber 6-2. The second pressure transmission medium 5-2 is sealed. The sealing of the first pressure transmission medium 5-1 into the first enclosure chamber 6-1 and the sealing of the second pressure transmission medium 5-2 into the second enclosure chamber 6-2 are as follows. Both are performed under the same conditions (under atmospheric pressure), and the sealing pressures of the first pressure transmission medium 5-1 and the second pressure transmission medium 5-2 are equal.

  In this sealed liquid sealing type differential pressure sensor 100, the pressure P1 received by the first pressure receiving diaphragm 2-1 is one surface 3 of the sensor diaphragm 3-1 via the first pressure transmission medium 5-1. The pressure P2 received by the second pressure receiving diaphragm 2-2 is transmitted to the other surface 3-1b of the sensor diaphragm 3-1 via the second pressure transmitting medium 5-2. As a result, the sensor diaphragm 3-1 bends according to the pressure difference between the pressures P1 and P2, and a signal according to the pressure difference is output from the sensor diaphragm 3-1. The sensor diaphragm 3-1 is formed with a strain resistance gauge whose resistance value changes according to a pressure change as a configuration for outputting a signal according to the pressure difference.

  For example, when the first pressure receiving diaphragm 2-1 side that receives the pressure P1 is the high pressure side and the second pressure receiving diaphragm 2-2 side that receives the pressure P1 is the low pressure side, the differential pressure sensor 100 has a high pressure on the low pressure side. When pressure (back pressure) higher than the side is applied, it has a weak point that it is fragile.

  That is, in this differential pressure sensor 100, when a higher pressure is applied to the high pressure side than to the low pressure side, the first joint portion 4-1 of the sensor chip 3 (the joint between the base 3-2 and the partition wall 1-1). Part (high-pressure side / low-pressure side boundary part)) and the second joint part 4-2 (joint part (high-pressure side / low-pressure side boundary part) between the pedestal 3-2 and the sensor diaphragm 3-1) are pressed. Therefore, the pressure resistance is high, but when a pressure (reverse pressure) higher than the high pressure side is applied to the low pressure side, a force is applied in the direction in which the joints 4-1 and 4-2 of the sensor chip 3 are peeled off. Therefore, it becomes fragile.

  For this reason, normally, the first pressure receiving diaphragm 2-1 side that receives the pressure P1 is used as the high pressure side, and the second pressure receiving diaphragm 2-2 side that receives the pressure P2 is used as the low pressure side.

  However, in the differential pressure sensor 100 having such a structure, the height relationship between the pressure P1 and the pressure P2 can be reversed or the height relationship between the pressure P1 and the pressure P2 is not reversed. The 2-1 side may be erroneously selected as the low-pressure side and the second pressure-receiving diaphragm 2-2 side as the high-pressure side, and the joints 4-1 and 4-2 of the sensor chip 3 may be peeled off or damaged. Abnormalities may occur.

  In this differential pressure sensor 100, when an abnormality such as peeling or breakage occurs in the joint portion 4-1 or 4-2 of the sensor chip 3, it is no longer possible to detect the correct differential pressure. Is desired.

Japanese Patent Laid-Open No. 3-175331 (Patent No. 2595749)

  However, abnormalities such as peeling or breakage of the joint portions 4-1 and 4-2 of the sensor chip 3 cannot be visually observed from the outside of the differential pressure sensor 100. Further, since the sealing pressures of the first pressure transmission medium 5-1 and the second pressure transmission medium 5-2 are equal, the internal pressure changes even if leakage occurs from the joints 4-1 and 4-2. Without this, the abnormality cannot be noticed only by the measured value of the zero point output of the differential pressure sensor 100.

  The measured value of the zero point output of the differential pressure sensor 100 is the output value of the signal from the sensor diaphragm 3-1 when the pressure difference between the pressures P1 and P2 to the pressure receiving diaphragms 2-1 and 2-2 is zero. Say. The measured value of the zero point output does not fluctuate because the internal pressure does not change even if leakage occurs from the joints 4-1 and 4-2. Therefore, the abnormality of the differential pressure sensor 100 cannot be noticed only by the measured value of the zero point output.

  For this reason, when the abnormality of the differential pressure sensor 100 is left for a long time, for example, when the flow control is performed in the plant, the air conditioning control system, or the like based on the differential pressure detected by the differential pressure sensor 100, an accurate flow rate is obtained. The influence of the malfunction due to the abnormality of the differential pressure sensor 100, such as the inability to perform control, is expanded.

  The present invention has been made to solve such a problem, and the object of the present invention is to provide an abnormality of the differential pressure sensor that can immediately know abnormality such as peeling or breakage of the joint portion of the sensor chip. An object of the present invention is to provide a diagnostic device and an abnormality diagnostic method.

  In order to achieve such an object, the present invention provides a body having a first space and a second space partitioned by a partition wall having a through passage, and a first provided in an opening of the first space. Pressure sensing diaphragm, a second pressure sensing diaphragm provided in the opening of the second space, and a sensor diaphragm that outputs a signal corresponding to a pressure difference received on one surface and the other surface, and one of the sensor diaphragms The sensor is joined to the wall surface of the partition wall located on the first space side so that the surface of the sensor diaphragm faces the first pressure receiving diaphragm and the communication path communicating with the other surface of the sensor diaphragm is communicated with the through path of the partition wall A chip, a first pressure transmission medium that is sealed in the first space and transmits the pressure received by the first pressure receiving diaphragm to one surface of the sensor diaphragm, and the second space and the partition wall A differential pressure sensor comprising: a second pressure transmission medium that is sealed in a communication path that communicates with the other surface of the passage and the sensor diaphragm, and that transmits the pressure received by the second pressure receiving diaphragm to the other surface of the sensor diaphragm The sealing pressure of the first pressure transmission medium is different from the sealing pressure of the second pressure transmission medium, and the sealing pressure of the first pressure transmission medium and the second pressure transmission medium are sealed. At least one of the stop pressures is monitored, and the presence / absence of abnormality of the differential pressure sensor is determined based on the fluctuation of the sealing pressure to be monitored from the initial sealing pressure.

  In the present invention, at least one of the sealing pressure of the first pressure transmission medium and the sealing pressure of the second pressure transmission medium is monitored. In this case, both the sealing pressure of the first pressure transmission medium and the sealing pressure of the second pressure transmission medium may be monitored, or one of them may be monitored.

  In the present invention, when both the sealing pressure of the first pressure transmission medium and the sealing pressure of the second pressure transmission medium are monitored, for example, the sealing pressure of the first pressure transmission medium and the second pressure The difference between the pressure transmission medium and the sealing pressure of the medium is monitored as a sealing pressure difference, and the presence or absence of an abnormality of the differential pressure sensor is determined based on a variation from the initial sealing pressure difference of the monitoring target sealing pressure difference. To. In the present invention, when monitoring any one of the sealing pressure of the first pressure transmission medium and the sealing pressure of the second pressure transmission medium, the initial sealing pressure of the sealing pressure to be monitored is monitored. The presence or absence of abnormality of the differential pressure sensor is determined based on the fluctuation.

  In the present invention, since the sealing pressure of the first pressure transmission medium is different from the sealing pressure of the second pressure transmission medium, an abnormality such as peeling or breakage occurs in the joint portion of the sensor chip. The pressure transmission medium flows from the higher sealing pressure to the lower sealing pressure, and the balance between the sealing pressure of the first pressure transmitting medium and the sealing pressure of the second pressure transmitting medium changes. Therefore, by setting the difference between the sealing pressure of the first pressure transmission medium and the sealing pressure of the second pressure transmission medium (sealing pressure difference) as the monitoring target, the initial sealing pressure difference of the monitoring target is determined. It is possible to determine whether or not there is an abnormality in the differential pressure sensor from the fluctuation from the enclosed pressure difference. Further, by setting one of the sealing pressure of the first pressure transmission medium and the sealing pressure of the second pressure transmission medium as a monitoring target, the initial sealing pressure of the monitoring pressure of the monitoring target is set. It becomes possible to determine the presence or absence of abnormality of the differential pressure sensor from the fluctuation from

  In the present invention, the difference between the sealing pressure of the first pressure transmission medium and the sealing pressure of the second pressure transmission medium is monitored as a sealing pressure difference, and the initial sealing of the sealing pressure difference to be monitored is performed. When it is determined whether or not there is an abnormality in the differential pressure sensor based on the fluctuation from the pressure difference, the measured value of the zero point output of the differential pressure sensor is used as the sealing pressure of the first pressure transmission medium and the second pressure transmission. Since it can be monitored as a difference from the sealing pressure of the working medium, abnormality diagnosis becomes easy. Further, in the present invention, if the presence / absence of an abnormality in the differential pressure sensor is determined, the presence / absence of an abnormality in the joint portion of the sensor chip can be determined. Useful for.

  In the present invention, if the sealing pressure of the first pressure transmission medium is higher than the sealing pressure of the second pressure transmission medium, the sealing pressure of the first pressure transmission medium and the second pressure transmission medium The pressure difference with the sealing pressure of the pressure transmission medium always acts in the direction in which the sensor chip joint is pressed, reducing the damage caused by the reverse pressure and making it difficult for the sensor chip joint to peel off. In this case, the pressure difference (sealing pressure difference) between the sealing pressure of the first pressure transmission medium and the sealing pressure of the second pressure transmission medium is the maximum differential pressure that may be applied as a reverse pressure and the sensor. It may be determined in relation to the bonding force of the chip bonding portion. That is, when the maximum differential pressure is applied as a reverse pressure, the first pressure transmission medium and the second pressure transmission medium are sealed with a pressure difference that can withstand the bonding force of the bonding portion of the sensor chip. It is good to do so.

  In the present invention, the sensor chip only needs to include a sensor diaphragm, and may not necessarily have a configuration including a sensor diaphragm and a pedestal. When the sensor chip is configured to include a sensor diaphragm and a pedestal, the joint portion of the sensor chip includes a joint portion between one end surface of the pedestal and the other surface side of the sensor diaphragm, the other end surface of the pedestal, and a partition wall. There are two places at the joint with the wall. When the sensor chip is configured only by the sensor diaphragm, the joint portion of the sensor chip is one place of the joint portion between the wall surface of the partition wall and the other surface side of the sensor diaphragm.

  According to the present invention, the sealing pressure of the first pressure transmission medium of the differential pressure sensor is different from the sealing pressure of the second pressure transmission medium. At least one of the sealing pressures of the second pressure transmission medium is monitored, and the presence / absence of abnormality of the differential pressure sensor is determined based on a change from the initial sealing pressure of the sealing pressure to be monitored. Therefore, the measured value of the zero point output of the differential pressure sensor is monitored as the difference between the sealing pressure of the first pressure transmission medium and the sealing pressure of the second pressure transmission medium, etc. It is possible to immediately know abnormalities such as peeling or breakage of parts.

  In the present invention, if the sealing pressure of the first pressure transmission medium is made higher than the sealing pressure of the second pressure transmission medium, the sealing pressure of the first pressure transmission medium The pressure difference from the sealing pressure of the second pressure transmission medium always acts in the direction in which the sensor chip joint is pressed, reducing the damage caused by the reverse pressure and making it difficult for the sensor chip joint to peel off. .

1 is a configuration diagram of a system provided with an embodiment of a differential pressure sensor abnormality diagnosis apparatus according to the present invention. FIG. It is sectional drawing which shows the principal part of another example of the differential pressure sensor diagnosed using this abnormality diagnosis apparatus. It is sectional drawing which shows the principal part of an example of the conventional sealing liquid sealing type differential pressure sensor.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 shows a system provided with an abnormality diagnosis device that performs abnormality diagnosis of the differential pressure sensor 200 during actual operation. In this system, in order to measure the flow rate of the fluid flowing through the valve 18 provided in the flow path 17, the upstream side (primary side) fluid pressure P1 and the downstream side (secondary side) fluid pressure P2 of the valve 18 The differential pressure is measured by the differential pressure sensor 200.

  1, the same reference numerals as those in FIG. 3 denote the same or equivalent components as those described with reference to FIG. 3, and the description thereof will be omitted. In this embodiment, the sealing pressure of the first pressure transmission medium 5-1 sealed in the first sealing chamber 6-1 of the differential pressure sensor 200 is sealed in the second sealing chamber 6-2. The sealing pressure of the stopped second pressure transmission medium 5-2 is set higher.

  In the differential pressure sensor 200, the sealing pressure of the first pressure transmission medium 5-1 is higher than the sealing pressure of the second pressure transmission medium 5-2. The differential pressure between the sealing pressure of 1 and the sealing pressure of the second pressure transmission medium 5-2 always acts in the direction in which the joint portions 4-1 and 4-2 of the sensor chip 3 are pressed.

  That is, in the conventional differential pressure sensor 100, when the sealing pressure of the first pressure transmission medium 5-1 and the sealing pressure of the second pressure transmission medium 5-2 are the same, a reverse pressure is applied. The joints 4-1 and 4-2 of the sensor chip 3 receive the pressure as it is.

  In contrast, in the differential pressure sensor 200, the sealing pressure of the first pressure transmission medium 5-1 is higher than the sealing pressure of the second pressure transmission medium 5-2. The differential pressure between the sealing pressure of the first pressure transmission medium 5-1 and the sealing pressure of the second pressure transmission medium 5-2 acts in the direction of reducing the reverse pressure. Thereby, the damage of a reverse pressure is reduced and peeling of the joining parts 4-1 and 4-2 of the sensor chip 3 is difficult to occur.

  In this differential pressure sensor 200, the pressure difference (sealing pressure difference) between the sealing pressure of the first pressure transmission medium 5-1 and the sealing pressure of the second pressure transmission medium 5-2 is opposite. It is determined by the relationship between the maximum differential pressure that may be applied as a pressure and the bonding force of the bonding portions 4-1 and 4-2 of the sensor chip 3. That is, when the maximum differential pressure is applied as a reverse pressure, the pressure difference is such that the bonding force of the bonding portions 4-1 and 4-2 of the sensor chip 3 can withstand the first pressure transmission medium 5-1. The second pressure transmission medium 5-2 is sealed.

  In this system, if an abnormality such as peeling or breakage occurs in the joint portion 4-1 or 4-2 of the sensor chip 3 of the differential pressure sensor 200, correct differential pressure cannot be measured. Therefore, in this system, an abnormality diagnosis unit 500 is provided as an abnormality diagnosis apparatus according to the present invention, and a signal ΔP output from the differential pressure sensor 200 is sent to the abnormality diagnosis unit 500 to diagnose whether there is an abnormality in the differential pressure sensor 200. The determination is made by the part 500.

  The abnormality diagnosis unit 500 is realized by hardware including a processor and a storage device, and a program that realizes various functions in cooperation with the hardware. The abnormality diagnosis unit 500 determines whether there is an abnormality in the differential pressure sensor 200 as follows.

  The abnormality diagnosis unit 500 sends an abnormality diagnosis start command sent when the pressures P1 and P2 to the pressure receiving diaphragms 2-1 and 2-2 are equal (for example, when the fluid flow rate Q to the valve 18 is zero). Accordingly, the signal ΔP output from the differential pressure sensor 200 is captured as a monitoring target. The value of the signal ΔP captured as the monitoring target is the difference (sealing) between the sealing pressure of the first pressure transmission medium 5-1 and the sealing pressure of the second pressure transmission medium 5-2 in the pressure sensor 200. Pressure difference).

  Here, if there is no abnormality such as peeling or breakage in the joint portions 4-1 and 4-2 of the sensor chip 3, the value of the signal ΔP taken in as a monitoring target should indicate the initial sealing pressure difference. is there. Here, the initial sealing pressure difference is a sealing pressure difference determined in the manufacturing stage of the differential pressure sensor 200. On the other hand, if abnormality such as peeling or breakage occurs in the joint portions 4-1 and 4-2 of the sensor chip 3, the pressure transmission medium flows from the higher sealing pressure to the lower pressure, and the first pressure The balance between the sealing pressure of the transmission medium 5-1 and the sealing pressure of the second pressure transmission medium 5-2 changes.

  Therefore, the abnormality diagnosis unit 500 determines that the differential pressure sensor 200 is normal if the value of the signal ΔP taken in as a monitoring target indicates an initial sealing pressure difference. On the other hand, if the value of the signal ΔP taken in as a monitoring target varies from the initial sealing pressure difference, it is determined that the differential pressure sensor 200 is abnormal.

  Needless to say, the determination of whether or not the value of the signal ΔP in the abnormality diagnosis unit 500 varies from the initial sealing pressure difference is made with a certain threshold. In addition, when the abnormality diagnosis unit 500 determines that the differential pressure sensor 200 is abnormal, the abnormality diagnosis unit 500 outputs a diagnosis result indicating that the joints 4-1 and 4-2 of the sensor chip 3 are abnormal. As a result, an abnormal part is specified, which is useful when analyzing the cause of the occurrence of the abnormality, and it is possible to take a quick response on site.

  In other words, in the failure analysis of the differential pressure sensor, in order to detect the breakage of the sensor chip joint (high-pressure side / low-pressure side boundary), the pressure change is applied to the differential pressure sensor and the output change rate is observed. Work is required, and it is difficult to find the cause on site. On the other hand, in this system, it is possible to immediately know the failure and the factor at the site based on the diagnosis result from the abnormality diagnosis unit 500, and it is possible to take a quick response.

  In this system, an abnormality diagnosis start command is sent to the abnormality diagnosis unit 500 when the pressures P1 and P2 to the pressure receiving diaphragms 2-1 and 2-2 are equal. The start command may be sent manually or automatically. For example, when this system is an air conditioning control system, an abnormality diagnosis start command is automatically sent to the abnormality diagnosis unit 500 when the fluid flow rate Q to the valve 18 is zero, such as at the start of the morning. .

  In this system, the signal ΔP output from the differential pressure sensor 200 is captured as a monitoring target. However, the sealing pressure of the first pressure transmission medium 5-1 and the second pressure transmission medium 5- One of the two sealing pressures is taken in as a monitoring target, and the presence / absence of abnormality of the differential pressure sensor 200 is determined based on the fluctuation from the initial sealing pressure of the taken-in sealing pressure. It may be.

  Further, in this differential pressure sensor 200, the sensor chip 3 is composed of the sensor diaphragm 3-1 and the pedestal 3-2, but the pedestal 3-2 is omitted and the sensor diaphragm 3 is omitted as shown in FIG. -1 may be the sensor chip 3 and may be configured to be bonded to the wall surface 1-1a of the partition wall 1-1. In the differential pressure sensor 300, the concave portion 3-1c of the sensor diaphragm 3-1 serves as a communication path 3-3 that communicates with the other surface 3-1b of the sensor diaphragm 3-1. Further, the sensor chip 3 has only one joint portion of the joint portion 4-1 between the other surface 3-1b side of the diaphragm 3-1 and the wall surface 1-1a of the partition wall 1-1.

  In the above description, the sealing pressure of the first pressure transmission medium 5-1 is set higher than the sealing pressure of the second pressure transmission medium 5-2. The sealing pressure of the medium 5-2 may be higher than the sealing pressure of the first pressure transmission medium 5-1. If the sealing pressure of the second pressure transmission medium 5-2 is made higher than the sealing pressure of the first pressure transmission medium 5-1, the damage of the reverse pressure cannot be reduced. Presence / absence of abnormality in the joint portions 4-1 and 4-2 of the sensor chip 3 due to a change in the balance between the sealing pressure of the pressure transmission medium 5-1 and the sealing pressure of the second pressure transmission medium 5-2. Can be determined.

  In the above-described embodiment, the sensor diaphragm 3-1 is a type in which a strain resistance gauge whose resistance value changes according to a pressure change is formed, but may be a capacitive sensor chip. A capacitance type sensor chip includes a substrate having a predetermined space (capacitance chamber), a diaphragm disposed in the space of the substrate, a fixed electrode formed on the substrate, and a movable electrode formed on the diaphragm. And. When the diaphragm is deformed by receiving pressure, the distance between the movable electrode and the fixed electrode changes, and the capacitance between them changes.

  In addition, even with a sealed liquid sealing type gauge pressure sensor and absolute pressure sensor, if the sealing part is made higher than the atmospheric release pressure, the sealing liquid leaks and the zero point shifts when the joint is broken. An effect can be obtained.

[Extension of the embodiment]
The present invention has been described above with reference to the embodiment. However, the present invention is not limited to the above embodiment. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the technical idea of the present invention.

  DESCRIPTION OF SYMBOLS 1 ... Body, 1-1 ... Partition, 1-1a ... Wall surface, 1-2 ... 1st space, 1-3 ... 2nd space, 1-4 ... Through-passage, 2-1 ... 1st pressure receiving diaphragm 2-2 ... second pressure receiving diaphragm, 3 ... sensor chip, 3-1 ... sensor diaphragm, 3-1a ... one surface, 3-1b ... other surface, 3-1c ... concave, 2-2 ... pedestal 3-3 ... Communication path, 4-1 ... first joint, 4-2 ... second joint, 5-1 ... first pressure transmission medium, 5-2 ... second pressure transmission Medium, 6-1... First enclosure chamber, 6-2. Second enclosure chamber, 200, 300... Differential pressure sensor, 500.

Claims (6)

A body having a first space and a second space partitioned by a partition wall having a through path;
A first pressure receiving diaphragm provided in an opening of the first space;
A second pressure receiving diaphragm provided in the opening of the second space;
A sensor diaphragm for outputting a signal corresponding to a pressure difference received on one surface and the other surface is provided, and one surface of the sensor diaphragm faces the first pressure receiving diaphragm and communicates with the other surface of the sensor diaphragm. A sensor chip joined to the wall surface of the partition wall located on the first space side so as to communicate the communication path with the through-passage of the partition wall;
A first pressure transmission medium sealed in the first space and transmitting the pressure received by the first pressure receiving diaphragm to one surface of the sensor diaphragm;
The second space, a through-passage of the partition wall, and a communication path that communicates with the other surface of the sensor diaphragm are sealed, and a pressure received by the second pressure receiving diaphragm is transmitted to the other surface of the sensor diaphragm. Two pressure transmission media,
An apparatus for diagnosing abnormality of a differential pressure sensor in which a sealing pressure of the first pressure transmission medium is different from a sealing pressure of the second pressure transmission medium,
At least one of the sealing pressure of the first pressure transmission medium and the sealing pressure of the second pressure transmission medium is monitored, and the monitoring pressure is changed based on a change from the initial sealing pressure. An abnormality diagnosing device for a differential pressure sensor, comprising: an abnormality determining means for determining whether or not there is an abnormality in the differential pressure sensor. In the abnormality diagnosis device for a differential pressure sensor according to claim 1,
The abnormality determining means includes
The difference between the sealing pressure of the first pressure transmission medium and the sealing pressure of the second pressure transmission medium is monitored as a sealing pressure difference, and the fluctuation of the monitoring target sealing pressure difference from the initial sealing pressure difference is monitored. An abnormality diagnosis device for a differential pressure sensor, wherein the presence or absence of abnormality of the differential pressure sensor is determined based on In the abnormality diagnosis device for a differential pressure sensor according to claim 1,
The abnormality determining means includes
The sealing pressure of any one of the sealing pressure of the first pressure transmission medium and the sealing pressure of the second pressure transmission medium is monitored, and the initial sealing pressure of the monitoring target sealing pressure is monitored. An apparatus for diagnosing an abnormality of the differential pressure sensor, wherein presence / absence of an abnormality of the differential pressure sensor is determined based on fluctuation. In the abnormality diagnosis device for a differential pressure sensor according to any one of claims 1 to 3,
The abnormality determining means includes
An apparatus for diagnosing an abnormality in a differential pressure sensor, wherein the presence or absence of an abnormality in a joint portion of the sensor chip is determined as the presence or absence of an abnormality in the differential pressure sensor. In the abnormality diagnosis device for a differential pressure sensor according to any one of claims 1 to 4,
The differential pressure sensor is
The differential pressure sensor abnormality diagnosis device, wherein the sealing pressure of the first pressure transmission medium is higher than the sealing pressure of the second pressure transmission medium. A body having a first space and a second space partitioned by a partition wall having a through path;
A first pressure receiving diaphragm provided in an opening of the first space;
A second pressure receiving diaphragm provided in the opening of the second space;
A sensor diaphragm for outputting a signal corresponding to a pressure difference received on one surface and the other surface is provided, and one surface of the sensor diaphragm faces the first pressure receiving diaphragm and communicates with the other surface of the sensor diaphragm. A sensor chip joined to the wall surface of the partition wall located on the first space side so as to communicate the communication path with the through-passage of the partition wall;
A first pressure transmission medium sealed in the first space and transmitting the pressure received by the first pressure receiving diaphragm to one surface of the sensor diaphragm;
The second space, a through-passage of the partition wall, and a communication path that communicates with the other surface of the sensor diaphragm are sealed, and a pressure received by the second pressure receiving diaphragm is transmitted to the other surface of the sensor diaphragm. An abnormality diagnosis method for a differential pressure sensor including two pressure transmission media,
The sealing pressure of the first pressure transmission medium is different from the sealing pressure of the second pressure transmission medium, and the sealing pressure of the first pressure transmission medium and the sealing of the second pressure transmission medium are different. A differential pressure sensor comprising: Abnormal diagnosis method.

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