JP2023076912A - pressure sensor - Google Patents

Abstract

To easily change at least one of a plurality of measurement ranges.SOLUTION: A pressure sensor 10 includes: a first diaphragm 21 to be deformed by receiving a first pressure P1 of a measured fluid; a second diaphragm 22 to be deformed by receiving a second pressure P2 of the measured fluid; and a plurality of differential pressure sensor chips 61-63 respectively constituted to detect a differential pressure between the first pressure P1 and the second pressure P2 and having a different measurement range. The pressure sensor 10 also includes a pressure transmission member 30 including: a first transmission channel 30A sealed with a first pressure transmission fluid F1 for transmitting the first pressure P1 to each one of the differential pressure sensor chips 61-63; and a second transmission channel 30B sealed with a second pressure transmission fluid F2 for transmitting the second pressure P2 to the respective differential pressure sensor chips 61-63.SELECTED DRAWING: Figure 1

Description

The present invention relates to pressure sensors.

Patent Literature 1 discloses a pressure sensor having multiple measurement ranges. In this pressure sensor, a plurality of diaphragms are provided in one differential pressure sensor chip, and the measurement range is changed by switching the diaphragm used for measurement.

JP-A-2002-13996

In the pressure sensor described in Patent Document 1, since a plurality of diaphragms are formed in one differential pressure sensor chip, for example, when it is desired to change a part of the measurement range in the manufacturing stage of the pressure sensor, , the entire differential pressure sensor chip must be redesigned. Here, the measurement range of the pressure measured by the pressure sensor often differs depending on where the pressure sensor is used, and the measurement range of the pressure sensor can be easily changed according to the delivery destination of the pressure sensor. It is desirable to

SUMMARY OF THE INVENTION It is an object of the present invention to make it possible to easily change at least one of a plurality of measurement ranges.

In order to achieve this object, the pressure sensor according to the present invention comprises a first diaphragm deformed by receiving a first pressure of a fluid to be measured, and a second diaphragm deformed by receiving a second pressure of the fluid to be measured. 2 diaphragms, a plurality of differential pressure sensor chips each configured to detect a differential pressure between the first pressure and the second pressure and having different measurement ranges, and the pressure received by the first diaphragm a first transmission path containing a first pressure transmission fluid for transmitting one pressure to each of the plurality of differential pressure sensor chips; and transmitting the second pressure received by the second diaphragm to each of the plurality of differential pressure sensor chips. and a pressure transmission member including a second transmission path in which a second pressure transmission fluid to be transmitted is enclosed.

The first transmission path extends from a 1-1 transmission path having a pressure receiving chamber at a first end facing the first diaphragm, and a second end opposite to the first end of the 1-1 transmission path. a first-second transmission path that branches off midway through and reaches each of the plurality of sensor chips, wherein the second transmission path has a pressure receiving chamber facing the second diaphragm at a first end; -1 transmission path, and a 2-2 transmission path extending from a second end opposite to the first end of the 2-1 transmission path and branching midway to reach each of the plurality of sensor chips; The pressure transmission member includes a first member forming the 1-1 transmission path and the 2-1 transmission path, and is connected to the first member, and comprises the 1-2 transmission path and the and a second member forming a 2-2 transmission path.

Each of the plurality of differential pressure sensor chips includes a sensor diaphragm that deforms due to the differential pressure, and a detection element that detects deformation of the sensor diaphragm. At least one of a size, a shape, a thickness, and a material differs among the plurality of differential pressure sensor chips so that each measurement range of the plurality of differential pressure sensor chips differs, and the plurality of differential pressure sensor chips is a first differential pressure sensor chip having a measurement range on the highest differential pressure side, and one or more second differential pressure sensor chips having a measurement range on a lower differential pressure side than the measurement range of the first differential pressure sensor chip, wherein at least one of the one or more second differential pressure sensor chips has an overpressure protection mechanism that prevents the sensor diaphragm from being deformed by the differential pressure and from further deformation due to contact with the sensor diaphragm. may be provided.

According to the present invention, the measurement range of the pressure sensor can be changed only by replacing the differential pressure sensor chip, and at least one of the plurality of measurement ranges can be easily changed.

1 is a partial cross-sectional view showing a schematic configuration of a pressure sensor according to an embodiment of the invention; FIG. 2 is a cross-sectional view showing a schematic configuration of a differential pressure sensor chip; FIG.

A pressure sensor according to an embodiment of the present invention will be described below with reference to the drawings. It should be noted that the vertical direction set in the drawings is set for convenience of explanation, and may differ from the actual top-to-bottom direction. For example, the pressure sensor may be installed so that the upper side in FIG. 1 faces the ground side in the vertical direction.

The pressure sensor 10 according to the present embodiment shown in FIG. A differential pressure between P2 and . The fluid to be measured may be liquid or gas. The pressure sensor 10 transmits the detected differential pressure to the outside. The pressure sensor 10 is configured here as a differential pressure transmitter. The transmitted differential pressure is used, for example, to measure the flow rate of the fluid to be measured. The pressure sensor 10 is arranged so that the first pressure P1 is the pressure on the low pressure side and the second pressure P2 is the pressure on the high pressure side.

As shown in FIG. 1, the pressure sensor 10 includes a first diaphragm 21, a second diaphragm 22, a pressure transmission member 30, a circuit section 40, a circuit housing member 50, differential pressure sensor chips 61 to 63, Prepare. In FIG. 1, the second member 32, the pin member 42, and the differential pressure sensor chips 61 to 63, which should be drawn as cross-sectional views, are drawn as elevation views seen from the front of the page of FIG. ing.

The first diaphragm 21 is in contact with the fluid to be measured having the first pressure P1 drawn through the predetermined flow path 91, and deforms by receiving the first pressure P1. The second diaphragm 22 is in contact with the fluid to be measured having the second pressure P2 drawn through the predetermined flow path 92, and is deformed by receiving the second pressure P2. Each of the diaphragms 21 and 22 is fixed to a first surface 31A and a second surface 31B of the four outer surfaces of the first member 31 of the pressure transmission member 30, the details of which will be described later. there is

The pressure transmission member 30 transmits the pressures P1 and P2 received by the diaphragms 21 and 22 respectively to the differential pressure sensor chips 61-63. The pressure transmission member 30 includes a square prism-shaped first member 31 and a second member 32 including three-pronged pipes 32A and 32B connected to the first member 31 . The first member 31 is also called a pressure receiving body. The diaphragms 21 and 22 are fixed to the first member 31 as described above, and the first pressure P1 and the second pressure P2 are received by pressure receiving chambers S1 and S2, which will be described later.

The pressure transmission member 30 has a first transmission path 30A including a 1-1 transmission path 30AA formed by the first member 31 and a 1-2 transmission path 30AB formed by the pipe 32A of the second member 32. Prepare. A first pressure transmission fluid F1 that transmits the first pressure P1 received by the first diaphragm 21 to the differential pressure sensor chips 61 to 63 is sealed in the first transmission path 30A.

The 1-1 transmission path 30AA has, as a first end, a pressure receiving chamber S1 facing the surface of the first diaphragm 21 opposite to the surface in contact with the fluid to be measured. The pressure-receiving chamber S<b>1 is formed of a recess opening in the first surface 31</b>A of the first member 31 . The pressure receiving chamber S<b>1 is sealed by the first diaphragm 21 . A portion of the 1-1 transmission path 30AA other than the pressure receiving chamber S1 is formed of a hole passing through the inside of the first member 31. As shown in FIG. A second end opposite to the first end of the 1-1 transmission path 30AA opens to the upper surface of the first member 31. As shown in FIG. One end of the pipe 32A of the second member 32 forming the 1-2 transmission path 30AB is inserted and connected to the second end of the 1-1 transmission path 30AA.

The 1st-2nd transmission path 30AB is composed of a hollow portion of a three-pronged pipe 32A that branches into three in the middle of the second member 32 . One end of the pipe 32A that is not branched is connected to the first member 31 as described above. The other three branched ends of the pipe 32A are connected to pressure input portions on the low pressure side of the differential pressure sensor chips 61 to 63, respectively. With such a configuration, the 1-2 transmission path 30AB extends from the second end of the 1-1 transmission path 30AA and branches midway to reach the differential pressure sensor chips 61-63.

The pressure transmission member 30 has a second transmission path 30B including a 2-1 transmission path 30BA formed by the first member 31 and a 2-2 transmission path 30BB formed by the pipe 32B of the second member 32. Prepare. A second pressure transmission fluid F2 that transmits the second pressure P2 received by the second diaphragm 22 to the differential pressure sensor chips 61 to 63 is sealed in the second transmission path 30B.

The 2-1 transmission path 30BA has, as a first end, a pressure receiving chamber S2 facing the surface of the second diaphragm 22 opposite to the surface in contact with the fluid to be measured. The pressure-receiving chamber S<b>2 is formed of a recess opening in the second surface 31</b>B of the first member 31 . The pressure receiving chamber S2 is sealed by the second diaphragm 22 . A portion of the 2-1 transmission path 30BA other than the pressure receiving chamber S2 is formed of a hole passing through the inside of the first member 31. As shown in FIG. A second end opposite to the first end of the 2-1 transmission path 30BA opens to the upper surface of the first member 31. As shown in FIG. One end of the pipe 32B of the second member 32 forming the 2-2 transmission path 30BB is inserted and connected to the second end of the 2-1 transmission path 30BA.

The 2-2 transmission path 30BB is composed of a hollow portion of a three-pronged pipe 32B that branches into three in the middle of the second member 32. One end of the unbranched pipe 32B is connected to the first member as described above. 31 is connected. The other three branched ends of the pipe 32B are connected to pressure input portions on the high pressure side of the differential pressure sensor chips 61 to 63, respectively. With this configuration, the 2-2 transmission path 30BB extends from the second end of the 2-1 transmission path 30BB and branches midway to reach the differential pressure sensor chips 61-63.

Circuit section 40 controls the operation of pressure sensor 10 . The circuit unit 40 includes a circuit board 41 on which the differential pressure sensor chips 61 to 63 are mounted, pin members 42 for external connection, and wires 43 connecting the circuit board 41 and the pin members 42 . The pin member 42 includes a plurality of connection pins 42A connected to the wiring 43, and a support portion 42B in which the connection pins 42A are embedded and supports the connection pins 42A.

The circuit housing member 50 houses the circuit section 40 . The circuit housing member 50 is fixed to the first member 31 of the pressure transmission member 30 . The circuit accommodating member 50 includes a tubular member 51 that accommodates the second member 32, the circuit board 41, and the differential pressure sensor chips 61 to 63, and is arranged in the tubular member 51. and a lid body 52 that covers the sensor chips 61 to 63 and the like. The lid 52 supports the pin members 42 of the circuit section 40 . The cylindrical member 51 and the lid 52 form a space S11 for receiving a connector for external wiring connected to the connection pin 42A.

Differential pressure sensor chips 61 to 63 are arranged on the upper surface of circuit board 41 . The pipes 32A and 32B of the second member 32, which are respectively connected to the differential pressure sensor chips 61 to 63, pass through three through-holes formed in the circuit board 41 from the bottom side to the top side of the circuit board 41. being pulled around.

When the first diaphragm 21 receives the first pressure P1 and deforms to swell to the right side of the drawing, the volume of the pressure receiving chamber S1 facing the first diaphragm 21 decreases. As a result, the first pressure transmission fluid F1 sealed in the first transmission path 30A including the pressure receiving chamber S1 is pushed toward the differential pressure sensor chips 61-63. As a result, the first pressure P1 received by the first diaphragm 21 is transmitted to each of the differential pressure sensor chips 61-63.

When the second diaphragm 22 receives the second pressure P2 and deforms to swell leftward in the drawing, the volume of the pressure receiving chamber S2 facing the second diaphragm 22 decreases. As a result, the second pressure transmission fluid F2 sealed in the second transmission path 30B including the pressure receiving chamber S2 is pushed toward the differential pressure sensor chips 61-63. Thereby, the second pressure P2 received by the second diaphragm 22 is transmitted to each of the differential pressure sensor chips 61-63.

Each of the differential pressure sensor chips 61-63 detects the differential pressure between the first pressure P1 transmitted via the first pressure transmission fluid F1 and the second pressure P2 transmitted via the second pressure transmission fluid F2. configured to detect The differential pressure sensor chips 61-63 have different measurement ranges.

The differential pressure sensor chip 61 has a low differential pressure measurement range, which is a relatively low differential pressure measurement range. That is, the differential pressure sensor chip 61 is formed as a highly sensitive sensor chip. The differential pressure sensor chip 62 has a middle differential pressure measurement range, which is a measurement range on the high differential pressure side of the low differential pressure measurement range of the differential pressure sensor chip 61 . The differential pressure sensor chip 63 has a high differential pressure measurement range that is on the high differential pressure side of the medium differential pressure measurement range of the differential pressure sensor chip 62 . The differential pressure sensor chips 61 to 63 are also collectively referred to as the differential pressure sensor chip 60 . The measurement range may be any range in which the reliability of the measured value is ensured. A portion of the high differential pressure side included in the low differential pressure measurement range and a portion of the low differential pressure side included in the middle differential pressure measurement range may overlap. A portion of the high differential pressure side included in the low differential pressure measurement range and a portion of the low differential pressure side included in the middle differential pressure measurement range may overlap. In this way, the measurement ranges that are different from each other may partially overlap.

The structure of the differential pressure sensor chips 61-63 is arbitrary. Here, one example of these structures will be described as the structure of the differential pressure sensor chip 60 with reference to FIG. For example, as shown in FIG. 2, the differential pressure sensor chip 60 has a laminated structure consisting of a first layer 60A, a second layer 60B and a third layer 60C.

The first layer 60A communicates with the recess 60AA formed in the upper surface thereof, the recess 60AA and the first-second transmission path 30AB of the first transmission path 30A shown in FIG. It has an introducing path 60AB. The first layer 60A is made of, for example, silicon.

The second layer 60B is formed on the first layer 60A and covers the recess 60AA of the first layer 60A. A portion of the second layer 60B covering the recess 60AA is a sensor diaphragm SD. A detection element D for detecting displacement of the sensor diaphragm SD is formed on the second layer 60B. The detection element D is composed of a strain gauge or the like using a semiconductor piezoresistive element. The second layer 60B includes, for example, a main layer made of silicon or the like, an active layer forming the detection element D formed by adding an impurity to a predetermined region of the main layer, and a main layer covering the active layer. and an insulating protective layer made of silicon oxide or the like formed in layers (in FIG. 2, the main layer and the insulating protective layer are depicted as one layer).

The third layer 60C is formed on the second layer 60B. The third layer 60C communicates with the recess 60CA covered by the second layer 60B, the recess 60CA and the 2-2 transmission path 30BB of the second transmission path 30B, and introduces the second pressure transmission fluid F2 into the recess 60CA. and an introduction passage 60CB. The lead-in path 60CB passes through the first layer 60A via the second layer 60B, and is thereby connected to the 2-2 transmission path 30BB located on the first layer 60A side. The third layer 60C is made of, for example, silicon.

A first pressure P1 is applied to the sensor diaphragm SD of the second layer 60B by a first pressure transmitting fluid F1 introduced into the recess 60AA of the first layer 60A. A second pressure P2 is applied to the sensor diaphragm SD by a second pressure transmission fluid F2 introduced into the recess 60CA of the third layer 60C. Therefore, the sensor diaphragm SD is deformed by the differential pressure between the first pressure P1 and the second pressure P2. As described above, since the first pressure P1 is lower than the second pressure P2 here, the sensor diaphragm SD deforms so as to expand toward the first layer 60A (lower side in FIG. 2). The detection element D outputs an electrical signal corresponding to the degree of deformation of the sensor diaphragm SD to the circuit board 41 shown in FIG. 1 through wiring (not shown) or the like. This electrical signal is, for example, a voltage signal having a voltage value corresponding to the degree of deformation of the sensor diaphragm SD. In this way, the sensing element D detects deformation of the sensor diaphragm SD.

Returning to FIG. 2, the inner surface Y of the recessed portion 60AA of the first layer 60A contacts the sensor diaphragm SD so that the deformed sensor diaphragm SD bulging toward the recessed portion 60AA is not deformed any more. Therefore, the inner surface Y can mechanically suppress excessive deformation of the sensor diaphragm SD due to excessive differential pressure. Thus, the inner surface Y functions as an overpressure protection mechanism that prevents further deformation of the sensor diaphragm SD, which has been deformed to the allowable upper limit degree of deformation. Hereinafter, this inner surface Y will also be referred to as an overpressure protection mechanism Y.

As described above, the differential pressure sensor chips 61-63 have different measurement ranges. Different measurement ranges are realized by having at least one of the size, shape, thickness and material of the sensor diaphragm SD differ among the differential pressure sensor chips 61-63. Note that the shape of the sensor diaphragm SD also includes an aspect ratio. The overpressure protection mechanism Y, that is, the shape of the inner surface Y is, of course, appropriately changed according to the shape of the sensor diaphragm SD.

Of the differential pressure sensor chips 61 to 63, the recessed portion 60AA of the first layer 60A of the differential pressure sensor chip 63 having the highest differential pressure side measurement range is formed in such a shape that the deformed sensor diaphragm SD does not come into contact with the inner surface Y. good too. That is, the differential pressure sensor chip 63 does not have to include the overpressure protection mechanism Y. This is because the differential pressure sensor chip 63 has a measurement range on the highest differential pressure side, and an excessive differential pressure is unlikely to occur for the differential pressure sensor chip 63 . For example, the recess 60AA may have a cubic shape as indicated by the dashed line in FIG.

When measuring the differential pressure between the first pressure P1 and the second pressure P2, the circuit board 41 of FIG. It is determined whether or not it is equal to or greater than the threshold. The first threshold is set in advance as an electric signal value corresponding to the upper limit of the measurement range of the differential pressure sensor chip 61 .

If the determination result is affirmative, the circuit board 41 derives the differential pressure based on the value. If the determination result is negative, the circuit board 41 determines whether the value such as the voltage value of the electric signal from the detection element D of the differential pressure sensor chip 62 is equal to or greater than the second threshold. The second threshold is set in advance as an electric signal value corresponding to the upper limit of the measurement range of the differential pressure sensor chip 62 . The first threshold value and the second threshold value are values of the electric signal output by the detection element D immediately before the deformed sensor diaphragm SD contacts the inner surface Y of the recess 60AA of the first layer 60A of the differential pressure sensor chip 61 or 62. and so on.

If the determination result of the differential pressure sensor chip 62 is affirmative, the circuit board 41 derives the differential pressure based on the value. If the determination result is negative, the circuit board 41 derives the differential pressure based on the value such as the voltage value of the electric signal from the detection element D of the differential pressure sensor chip 63 .

The circuit board 41 outputs the differential pressure derived in response to any of the determination results described above in the form of, for example, a DC electric signal of 4 to 20 mA to the outside, for example, a host device via the wiring 43 and the pin member 42. .

As described above, in this embodiment, a plurality of differential pressure sensor chips 61-63 realize a plurality of measurement ranges. Therefore, by preparing a plurality of types of differential pressure sensor chips in advance and changing the differential pressure sensor chip to be mounted on the pressure sensor 10, the measurement range of the pressure sensor 10 to be manufactured can be changed. Therefore, at least one of the multiple measurement ranges of the pressure sensor can be easily changed. This makes it possible to easily manufacture a pressure sensor having a measurement range desired by the shipping destination. In addition, since a plurality of measurement ranges are mounted on one pressure sensor 10, there is no need to prepare a plurality of pressure sensors for each measurement range, and cost reduction and space saving of introduction of pressure sensors are realized.

Further, in this embodiment, the transmission paths 30A and 30B for transmitting the pressures P1 and P2 of the diaphragms 21 and 22 are branched corresponding to the plurality of differential pressure sensor chips 60. FIG. A member constituting the 1-1 transmission path 30AA and the 2-1 transmission path 30BA before branching is a first member 31, and a member constituting the 1-2 transmission path 30AB and the 2-2 transmission path 30BB is the second member 32 . In this way, by separating the members forming the 1-1 transmission path 30AA and the 2-1 transmission path 30BA from the members forming the 1-2 transmission path 30AB and the 2-2 transmission path 30BB, For the first member 31 forming the 1-1 transmission path 30AA and the 2-1 transmission path 30BA, a pressure receiving body or the like used in a conventional differential pressure transmitter can be used. As a result, the structure according to the present embodiment can be obtained with few changes from the conventional structure.

Further, in the above embodiment, the plurality of differential pressure sensor chips 61 to 63 are the first differential pressure sensor chip, which is the differential pressure sensor chip 63 having the highest differential pressure side measurement range, and the first differential pressure sensor chip. and one or more second differential pressure sensor chips, which are two differential pressure sensor chips 61 and 62 having a measuring range on the lower differential pressure side than the measuring range of . At least one of the one or more second differential pressure sensor chips has an overpressure protection mechanism (inner surface) Y that prevents further deformation of the sensor diaphragm SD due to contact with the sensor diaphragm SD. There is a trade-off relationship between the measurement range of the sensor diaphragm SD, that is, the measurement sensitivity of the differential pressure, and the pressure resistance. By providing the excessive pressure protection mechanism Y for the second differential pressure sensor chip having a relatively low differential pressure measurement range, pressure resistance is ensured while increasing differential pressure measurement sensitivity. Furthermore, excessive deformation of the sensor diaphragm SD is suppressed, and the inconvenience of the sensor diaphragm SD constantly flexing due to excessive deformation and a decrease in differential pressure measurement accuracy is suppressed. Therefore, the pressure sensor of the present embodiment enables accurate differential pressure measurement.

Various modifications are possible for the embodiments described above. For example, the shape of each member described in the above embodiment is arbitrary. Although the pressure sensor 10 has three differential pressure sensor chips 61 to 63 in the above embodiment, the pressure sensor according to the present invention may have a plurality of differential pressure sensor chips. The differential pressure sensor chip may be a chip that detects differential pressure in a form other than a diaphragm. The plurality of differential pressure sensor chips may be configured as components separate from each other. The second member 32 may be formed in a cubic shape like the first member 31 . The cubic holes may be used as the 1-2 transmission path 30AB and the 2-2 transmission path 30BB. Instead of the first member 31 and the second member 32, a combination of a member forming the entire first transmission path 30A and a member forming the entire second transmission path 30B, the first transmission path 30A and the second transmission path A member or the like forming all of 30B may also be employed. Each diaphragm 21 and 22 may be arranged, for example, so as to face in the vertical direction. The configuration of the overpressure protection mechanism Y is also arbitrary. The overpressure protection mechanism Y may have any configuration that mechanically suppresses excessive deformation of the sensor diaphragm SD, for example.

Reference Signs List 10 Pressure sensor 21 First diaphragm 22 Second diaphragm 30 Pressure transmission member 30A First transmission path 30AA First-first transmission path 30AB First-second transmission path 30B 2nd transmission path 30BA 2-1 transmission path 30BB 2-2 transmission path 31 first member 31A first surface 31B second surface 32 second member 32A, 32B 40 Pipe 40 Circuit portion 41 Circuit board 42 Pin member 42A Connection pin 42B Support portion 43 Wiring 50 Circuit accommodating member 51 Cylindrical member 52 Cover 60 Differential pressure sensor chip 60A First layer 60AA Recess 60AB Introduction path 60B Second layer 60C Third layer 60CA Recess 60CB Introduction path 61 to 63 Differential pressure sensor chip , 91, 92... flow path, D... detecting element, F1... first pressure transmission fluid, F2... second pressure transmission fluid, P1... first pressure, P2... second pressure, S1, S2... pressure receiving chamber, S11... Space, SD... sensor diaphragm, Y... inner surface (overpressure protection mechanism).

Claims (3)

a first diaphragm deformed by receiving a first pressure of the fluid to be measured;
a second diaphragm deformed by receiving the second pressure of the fluid to be measured;
a plurality of differential pressure sensor chips each configured to detect a differential pressure between the first pressure and the second pressure and having different measurement ranges;
a first transmission path containing a first pressure transmission fluid for transmitting the first pressure received by the first diaphragm to each of the plurality of differential pressure sensor chips; and the second pressure received by the second diaphragm. a pressure transmission member comprising: a second transmission path containing a second pressure transmission fluid that is transmitted to each of the plurality of differential pressure sensor chips;
a pressure sensor. The first transmission path is
a 1-1 transmission path having a pressure receiving chamber facing the first diaphragm at a first end;
a 1-2 transmission path that extends from a second end opposite to the first end of the 1-1 transmission path, branches midway, and reaches each of the plurality of sensor chips;
The second transmission path is
a 2-1 transmission path having a pressure receiving chamber at a first end facing the second diaphragm;
a 2-2 transmission path that extends from a second end opposite to the first end of the 2-1 transmission path, branches midway, and reaches each of the plurality of sensor chips;
The pressure transmission member is
a first member forming the 1-1 transmission path and the 2-1 transmission path;
a second member connected to the first member and forming the 1-2 transmission path and the 2-2 transmission path;
A pressure sensor according to claim 1 . each of the plurality of differential pressure sensor chips includes a sensor diaphragm that deforms due to the differential pressure, and a detection element that detects deformation of the sensor diaphragm;
wherein at least one of size, shape, thickness, and material of the sensor diaphragm of each of the plurality of differential pressure sensor chips is different among the plurality of differential pressure sensor chips, whereby the plurality of differential pressure sensor chips each measuring range is different,
The plurality of differential pressure sensor chips include a first differential pressure sensor chip having a measurement range on the highest differential pressure side and one or more differential pressure sensor chips having a measurement range on a lower differential pressure side than the measurement range of the first differential pressure sensor chip. 2 differential pressure sensor chips;
At least one of the one or more second differential pressure sensor chips has an overpressure protection mechanism that prevents further deformation of the sensor diaphragm due to contact with the sensor diaphragm deformed by the differential pressure,
The pressure sensor according to claim 1 or 2.

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