Isolated pressure sensor

Abstract

The present invention discloses an isolated pressure sensor, which includes a diaphragm pressure sensor and two pressure-taking seats arranged opposite to each other. There is a pressure-leading seat between the two pressure-taking seats. Two pressure-leading channels penetrate through the pressure-leading seat. One end of the pressure-leading channel is an inlet, and the other end is an outlet. Pressure-taking channels penetrate through the two pressure-taking seats respectively. The inner end of the pressure-taking channel is butted against the inlet end of the corresponding pressure-leading channel, and the outer end of the pressure-taking channel penetrates out of the corresponding pressure-taking seat. The diaphragm pressure sensor leads out two pressure-leading pipes outward. The inner ends of the two pressure-leading pipes are connected to the inside of the diaphragm pressure sensor, and the outer ends of the two pressure-leading pipes are respectively connected to the outlet ends of the two pressure-leading channels. By using the isolated pressure sensor of the present invention and the isolated installation method, it is avoided that the isolation diaphragm and / or the welding ring abut against the assembly part, and the isolation diaphragm will not be deformed during the installation process, thus solving the influence of clamping stress on the measurement accuracy.

Description

Technical Field

[0001] The present invention relates to a pressure measuring device, and particularly to an isolated pressure sensor. Background Art

[0002] The core detection component of a capacitance differential pressure transmitter is a diaphragm type capacitance differential pressure sensor (diaphragm type pressure sensor), which converts two externally applied different pressure signals into respective capacitance changes, and the subsequent detection circuit converts the capacitance change into an electrical signal, and by processing and detecting this electrical signal, the differential pressure value of the externally applied pressure can be obtained.

[0003] The diaphragm type pressure sensor includes two disc-shaped diaphragm seats, the edges of the two diaphragm seats are welded, a diaphragm deformation cavity is provided between the two diaphragm seats, a measuring diaphragm is provided between the two diaphragm seats, and pressure transmission channels penetrate through the two diaphragm seats respectively, which introduce the externally measured pressure to both sides of the measuring diaphragm, and the magnitude of the deformation of the measuring diaphragm reflects the magnitude of the differential pressure.

[0004] The traditional installation method of the diaphragm type pressure sensor is to provide an isolation diaphragm on the outer wall of the diaphragm seat, the isolation diaphragm closes the outer port of the pressure transmission channel. In order to facilitate the installation and stability of the isolation diaphragm, a welding ring is generally provided on the outside of the isolation diaphragm, and then silicone oil is filled in the pressure transmission channel and the diaphragm deformation cavity to keep the measuring diaphragm in a fixed initial position, and a stable pressure system is formed inside the diaphragm type pressure sensor; the above isolation diaphragm is fixed on the diaphragm type pressure sensor and installed together later; this leads to the following two main problems:

[0005] 1. During the later assembly process, the isolation diaphragm and / or the welding ring abut against the assembly part. Affected by the clamping stress, the isolation diaphragm is prone to deformation, thereby pushing the internal silicone oil to flow, causing different changes in the initial position of the measuring diaphragm of each transmitter, and affecting the measurement accuracy;

[0006] 2. When measuring high-pressure fluid, the internal pressure in the deformation cavity increases significantly, and there is a tendency to push the welds of the two diaphragm seats to crack, and this situation becomes more serious with the increase of time and pressure, which is not conducive to extending the service life of the diaphragm type pressure sensor.

[0007] Therefore, it is necessary to comprehensively consider and solve the above problems and design a set of suitable technical solutions. Summary of the Invention

[0008] In view of this, the present invention provides an isolated pressure sensor.

[0009] The technical solution is as follows:

[0010] An isolated pressure sensor, characterized in that: it includes a diaphragm pressure sensor and two pressure-taking seats arranged opposite to each other, and a pressure-leading seat is arranged between the two pressure-taking seats;

[0011] Two pressure-leading channels penetrate through the pressure-leading seat. One end of the pressure-leading channel is an inlet, and the other end of the pressure-leading channel is an outlet. The inlet ends of the two pressure-leading channels respectively face the two pressure-taking seats;

[0012] Pressure-taking channels penetrate through the two pressure-taking seats respectively. The inner end of the pressure-taking channel is butted against the inlet end of the corresponding pressure-leading channel, and the outer end of the pressure-taking channel penetrates out of the corresponding pressure-taking seat;

[0013] Two pressure-leading pipes are led outwards from the diaphragm pressure sensor. The inner ends of the two pressure-leading pipes are connected to the inside of the diaphragm pressure sensor, and the outer ends of the two pressure-leading pipes are respectively connected to the outlet ends of the two pressure-leading channels.

[0014] Pressure-leading pipe sockets are respectively arranged around the outlet ends of the pressure-leading channels on the pressure-leading seat. The outer ends of the pressure-leading pipes are inserted into the corresponding pressure-leading pipe sockets, and the outer wall of the pressure-leading pipe is welded and sealed with the pressure-leading pipe socket.

[0015] The outlet ends of the two pressure-leading channels penetrate out from the same side of the pressure-leading seat. A placement sink is also arranged on the pressure-leading seat between the outlet ends of the two pressure-leading channels. The lower part of the diaphragm pressure sensor floats in the placement sink.

[0016] Two mutually parallel installation sides are arranged on the pressure-leading seat in a back-to-back manner. The inlet ends of the two pressure-leading channels respectively penetrate out from the two installation sides. An annular diaphragm installation seat is arranged around the inlet end of the pressure-leading channel on the installation side. The diaphragm installation seat is an annular welding boss. The inside of the diaphragm installation seat encloses a pressure-leading area. The port of the inlet end of the pressure-leading channel is respectively located in the corresponding pressure-leading area. The two pressure-taking seats correspond to the two installation sides one by one. An assembly plane is arranged on the pressure-taking seat corresponding to its installation side. The assembly plane is attached to and sealed with the corresponding installation side. A pressure-taking area is arranged on the assembly plane corresponding to the pressure-leading area. The inner end of the pressure-taking channel is connected to the pressure-taking area, and the pressure-taking area is butted against the corresponding pressure-leading area.

[0017] The pressure-leading seat includes an installation base and a sensor installation seat. The installation base is in a cubic shape. Two opposite sides of the installation base form the two installation sides. The installation sides are arranged vertically. The sensor installation seat is fixed on the upper end surface of the installation base. The outlet ends of the two pressure-leading channels respectively penetrate out from the upper end surface of the sensor installation seat;

[0018] The sensor mounting base includes a horizontally placed docking plate, the lower surface of which is fixed to the upper end surface of the mounting base. A docking seat is fixed on the upper surface of the docking plate. The edge of the docking plate extends outward and exceeds the docking seat. The pressure guiding pipe socket is located on the upper surface of the docking seat. The outer wall of the docking seat is provided with a socket thread. The outlet end of the pressure guiding channel penetrates out from the upper end surface of the docking seat. The outlet ends of the two pressure guiding channels are at the same horizontal height. The projection of the connection line of the outlet ends of the two pressure guiding channels on the horizontal plane forms an angle α with the mounting side surface, and α = 45°.

[0019] A sealing cover is sleeved on the docking seat, and the sealing cover is threadedly sleeved on the docking seat. The sealing cover abuts against the docking plate and is welded and sealed;

[0020] A pressure balance channel also penetrates through the pressure guiding seat. The pressure balance channel is vertically arranged. The upper end of the pressure balance channel penetrates upward out of the docking seat, and the lower end of the pressure balance channel penetrates downward out of the mounting base. The lower end of the pressure balance channel is connected to the same pressure source as the inlet end of the pressure guiding channel.

[0021] Isolation diaphragms are respectively arranged at the inlet ends of the two pressure guiding channels and at the lower end of the pressure balance channel. The edge of the isolation diaphragm is sealed and fixed to the corresponding part of the pressure guiding seat;

[0022] The isolation diaphragm for blocking the inlet end of the pressure guiding channel is covered on the pressure guiding area, and its edge is welded and sealed to the annular welding boss;

[0023] The pressure guiding channel, the pressure guiding pipe and the inside of the diaphragm type pressure sensor are internally connected. The pressure balance channel and the inside of the sealing cover are internally connected. The inside and outside of the diaphragm type pressure sensor are isolated from each other;

[0024] The pressure guiding channel, the pressure guiding pipe, the inside of the diaphragm type pressure sensor, the pressure balance channel and the inside of the sealing cover are filled with a pressure transmission medium.

[0025] A steering counterbore is provided on the bottom surface of the mounting base around the lower end port of the pressure balance channel;

[0026] The isolation diaphragm for blocking the lower end port of the pressure balance channel is provided at the bottom of the steering counterbore, and its edge is welded and sealed to the bottom of the steering counterbore;

[0027] An end plug is also fixedly provided at the outer end of the steering counterbore. A balanced pressure-taking area is formed between the end plug and the corresponding isolation diaphragm. A balanced pressure-taking hole also penetrates through the hole wall of the steering counterbore. The inner end of the balanced pressure-taking hole is communicated with the balanced pressure-taking area, and the outer end of the balanced pressure-taking hole penetrates out of the mounting base. The outer end of the balanced pressure-taking hole and the inlet end of any one of the pressure-inducing channels are located on the same side of the mounting base.

[0028] A pressure-taking branch hole is also provided on the pressure-taking seat. One end of the pressure-taking branch hole is communicated with the pressure-taking area, and the other end of the balanced pressure-taking hole is communicated with the pressure-taking branch hole on any one of the pressure-taking seats.

[0029] Compared with the prior art, the beneficial effects of the present invention are as follows: The isolated installation method is adopted, which avoids the isolation diaphragm and / or the welding ring from abutting against the assembly part. The isolation diaphragm will not be deformed during the installation process, and the influence of clamping stress on the measurement accuracy is solved. Description of the Drawings

[0030] Figure 1 is a schematic structural diagram of the present invention;

[0031] Figure 2 is a cross-sectional schematic diagram of the installation structure of the present invention;

[0032] Figure 3 is Figure 2 an enlarged view of part D of

[0033] Figure 4 is a schematic diagram of the connection relationship between the diaphragm pressure sensor 25 and the mounting base 23;

[0034] Figure 5 is Figure 4 an enlarged view of part C of

[0035] Figure 6 is a cross-sectional schematic diagram of the connection relationship between the diaphragm pressure sensor 25, the mounting base 23 and the sealing cover 3;

[0036] Figure 7 is Figure 6 an enlarged view of part A of

[0037] Figure 8 is Figure 6 an enlarged view of part B of

[0038] Figure 9 is a schematic structural diagram of the mounting base 23;

[0039] Figure 10 is Figure 9 a top view of

[0040] Figure 11 is Figure 10Z-Z` cross-sectional view. Detailed implementation

[0041] The present invention will be further described below in conjunction with embodiments and drawings.

[0042] As Figures 1 to 11 shown, an isolated pressure sensor includes a pressure guiding seat 2 and a sealing cover 3. The sealing cover 3 is sleeved on the pressure guiding seat 2. A diaphragm pressure sensor 25 is arranged in the sealing cover 3. A lead outlet is arranged at the top of the sealing cover 3. The diaphragm pressure sensor 25 is connected with a signal lead, and the signal lead passes outwards through the lead outlet. A lead connector 31 is wrapped on the signal lead, and the lead connector 31 plugs in the lead outlet and is sealed with it.

[0043] A negative pressure oil injection hole 3a is further arranged on the sealing cover 3, and an oil plug 32 is arranged in the negative pressure oil injection hole 3a.

[0044] Among them:

[0045] The negative pressure oil injection hole 3a includes a threaded hole section, a tapered hole section and a small hole section that are connected in sequence. The large end of the tapered hole section is connected with the threaded hole section, and the small end of the tapered hole section is connected with the small hole section. A sealing ball 33 is arranged in the tapered hole section. The oil plug 32 is screwed in the threaded hole section, and the oil plug 32 presses the sealing ball 33 against the hole wall of the tapered hole section.

[0046] It further includes two pressure taking seats 1 arranged opposite to each other, and the pressure guiding seat 2 is arranged between the two pressure taking seats 1;

[0047] Two pressure guiding channels 2a penetrate through the pressure guiding seat 2. One end of the pressure guiding channel 2a is an inlet, and the other end of the pressure guiding channel 2a is an outlet. The inlet ends of the two pressure guiding channels 2a face the two pressure taking seats 1 respectively;

[0048] Pressure taking channels 1a penetrate through the two pressure taking seats 1 respectively. The inner end of the pressure taking channel 1a is butted with the inlet end of the corresponding pressure guiding channel 2a, and the outer end of the pressure taking channel 1a passes out of the corresponding pressure taking seat 1;

[0049] Two pressure guiding pipes 251 are led outwards from the diaphragm pressure sensor 25. The inner ends of the two pressure guiding pipes 251 are connected with the inside of the diaphragm pressure sensor 25, and the outer ends of the two pressure guiding pipes 251 are respectively connected with the outlet ends of the two pressure guiding channels 2a.

[0050] In specific implementation, the free ends of the two pressure guiding pipes 251 are respectively connected with a high-pressure source and a low-pressure source.

[0051] On the pressure guiding seat 2, pressure guiding pipe sockets 22 are respectively arranged around the outlet end of the pressure guiding channel 2a. The outer end of the pressure guiding pipe 251 is inserted into the corresponding pressure guiding pipe socket 22, and the outer wall of the pressure guiding pipe 251 is welded and sealed with the pressure guiding pipe socket 22.

[0052] The outlet ends of the two pressure guiding channels 2a penetrate out from the same side surface of the pressure guiding seat 2. A placing sink is further arranged on the pressure guiding seat 2 between the outlet ends of the two pressure guiding channels 2a. The lower part of the diaphragm pressure sensor 25 is suspended in the placing sink.

[0053] Two mutually parallel mounting side surfaces are provided on the pressure guiding seat 2 in a back-to-back manner. The inlet ends of the two pressure guiding channels 2a respectively penetrate out from the two mounting side surfaces. An annular diaphragm mounting seat 21 is arranged around the inlet end of the pressure guiding channel 2a on the mounting side surface. The diaphragm mounting seat 21 is an annular welding boss. The interior of the diaphragm mounting seat 21 encloses a pressure guiding area. The port of the inlet end of the pressure guiding channel 2a is respectively located in the corresponding pressure guiding area. The two pressure tapping seats 1 correspond to the two mounting side surfaces one by one. An assembling plane is provided on the pressure tapping seat 1 corresponding to its mounting side surface. The assembling plane is attached and sealed with the corresponding mounting side surface. A pressure tapping area 1b is provided on the assembling plane corresponding to the pressure guiding area. The inner end of the pressure tapping channel 1a is communicated with the pressure tapping area 1b. The pressure tapping area 1b is butted against the corresponding pressure guiding area.

[0054] The pressure guiding seat 2 includes a mounting base 23 and a sensor mounting seat 24. The mounting base 23 is in a cubic shape. Two opposite side surfaces of the mounting base 23 form the two mounting side surfaces. The mounting side surfaces are arranged vertically. The sensor mounting seat 24 is fixed to the upper end surface of the mounting base 23. The outlet ends of the two pressure guiding channels 2a respectively penetrate out from the upper end surface of the sensor mounting seat 24;

[0055] The sensor mounting seat 24 includes a horizontally placed docking plate 241. The lower surface of the docking plate 241 is fixed to the upper end surface of the mounting base 23. A docking seat 242 is fixed to the upper surface of the docking plate 241. The edge of the docking plate 241 extends outward and exceeds the docking seat 242. The pressure guiding pipe socket 22 is located on the upper surface of the docking seat 242. A socket thread is provided on the outer wall of the docking seat 242. A sealing cover 3 is sleeved on the docking seat 242. The sealing cover 3 is threadedly sleeved on the docking seat 242. The sealing cover 3 abuts against the docking plate 241 and is welded and sealed;

[0056] The outlet ends of the pressure guiding channels 2a penetrate out from the upper end surface of the docking seat 242. The outlet ends of the two pressure guiding channels 2a are at the same horizontal height. The projection of the connection line of the outlet ends of the two pressure guiding channels 2a on the horizontal plane forms an angle α with the installation side surface, and α = 45°.

[0057] To further improve the pressure balance effect, a pressure balance channel 2b also penetrates through the pressure guiding seat 2. The pressure balance channel 2b is vertically arranged. The upper end of the pressure balance channel 2b penetrates upward through the docking seat 242, and the lower end of the pressure balance channel 2b penetrates downward through the installation base 23. The lower end of the pressure balance channel 2b is connected to the same pressure source as the inlet end of the pressure guiding channel 2a.

[0058] Isolation diaphragms 26 are respectively arranged at the inlet ends of the two pressure guiding channels 2a and at the lower end of the pressure balance channel 2b. The edge of the isolation diaphragm 26 is sealed and fixed to the corresponding pressure guiding seat 2;

[0059] The isolation diaphragm 26 for blocking the inlet end of the pressure guiding channel 2a is covered on the pressure guiding area, and its edge is welded and sealed to the annular welding boss;

[0060] The pressure guiding channels 2a, the pressure guiding pipes 251 and the diaphragm type pressure sensor 25 are internally connected. The pressure balance channel 2b and the inside of the sealing cover 3 are internally connected. The inside and outside of the diaphragm type pressure sensor 25 are isolated from each other;

[0061] The pressure guiding channels 2a, the pressure guiding pipes 251, the inside of the diaphragm type pressure sensor 25, the pressure balance channel 2b, and the inside of the sealing cover 3 are filled with a pressure transmission medium.

[0062] A steering counterbore 2c is arranged on the bottom surface of the installation base 23 around the lower end port of the pressure balance channel 2b;

[0063] The isolation diaphragm 26 for blocking the lower end port of the pressure balance channel 2b is arranged at the bottom of the steering counterbore 2c, and its edge is welded and sealed to the bottom of the steering counterbore 2c;

[0064] A plug 27 is also fixedly arranged at the outer end of the steering counterbore 2c. A balance pressure taking area is formed between the plug 27 and the corresponding isolation diaphragm 26. A balance pressure taking hole 2d also penetrates through the hole wall of the steering counterbore 2c. The inner end of the balance pressure taking hole 2d is connected to the balance pressure taking area. The outer end of the balance pressure taking hole 2d penetrates out of the installation base 23. The outer end of the balance pressure taking hole 2d and the inlet end of any one of the pressure guiding channels 2a are on the same side surface of the installation base 23;

[0065] A pressure-taking branch hole 1c is further provided on the pressure-taking seat 1. One end of the pressure-taking branch hole 1c is communicated with the pressure-taking area 1b, and the other end of the balanced pressure-taking hole 2d is communicated with the pressure-taking branch hole 1c on any one of the pressure-taking seats 1. Preferably, the outer end of the pressure balance channel 2b is connected to the high-pressure source.

[0066] Two first negative-pressure oil injection holes are further provided on the pressure-leading seat 2, and two first negative-pressure oil injection holes penetrate through the sealing cover 3. The two first negative-pressure oil injection holes respectively correspond to two pressure-leading areas. One end of the first negative-pressure oil injection hole penetrates out of the pressure-leading seat 2, and the other end of the first negative-pressure oil injection hole is communicated with the corresponding pressure-leading area. A second negative-pressure oil injection hole 3a also penetrates through the sealing cover 3, and the second negative-pressure oil injection hole 3a connects the inside and outside of the sealing cover 3;

[0067] In the above structure, except for the sealing cover 3, other components are first installed as a whole, and vacuum is pumped through the two first negative-pressure oil injection holes to keep the vacuum degree consistent. Then, by switching the valves of the gas path and the oil path, silicone oil is injected into the two first negative-pressure oil injection holes. The silicone oil will fill the inside of the pressure-leading area, the pressure-leading channel 2a, the pressure-leading pipe 251, and the diaphragm pressure sensor 25. Then, a first oil plug is arranged in the first negative-pressure oil injection hole for plugging; then, check whether there is oil leakage. If no oil leakage is found, then assemble the sealing cover 3 and complete the sealing, and pump vacuum through the second negative-pressure oil injection hole 3a. Then, by switching the valves of the gas path and the oil path, silicone oil is injected into the second negative-pressure oil injection hole 3a. The silicone oil will fill the inside of the sealing cover 3 (installation cavity) and the pressure balance channel 2b. Finally, a second oil plug 32 is arranged in the negative-pressure oil injection hole 3a for plugging.

[0068] Finally, it should be noted that the above description is only the preferred embodiment of the present invention. Under the inspiration of the present invention, those of ordinary skill in the art can make various similar representations without violating the purpose and claims of the present invention. Such transformations all fall within the protection scope of the present invention.

Claims

1. An isolated pressure sensor, characterized in that: It includes a diaphragm pressure sensor (25) and two pressure-taking seats (1) arranged opposite to each other, and a pressure-leading seat (2) is provided between the two pressure-taking seats (1); Two pressure-leading channels (2a) penetrate through the pressure-leading seat (2). One end of the pressure-leading channel (2a) is an inlet, and the other end of the pressure-leading channel (2a) is an outlet. The inlet ends of the two pressure-leading channels (2a) face the two pressure-taking seats (1) respectively; Pressure-taking channels (1a) penetrate through the two pressure-taking seats (1) respectively. The inner end of the pressure-taking channel (1a) is butted against the inlet end of the corresponding pressure-leading channel (2a), and the outer end of the pressure-taking channel (1a) penetrates out of the corresponding pressure-taking seat (1); Two pressure-leading pipes (251) are led outwards from the diaphragm pressure sensor (25). The inner ends of the two pressure-leading pipes (251) are connected to the inside of the diaphragm pressure sensor (25), and the outer ends of the two pressure-leading pipes (251) are respectively connected to the outlet ends of the two pressure-leading channels (2a); Pressure-leading pipe sockets (22) are respectively arranged around the outlet ends of the pressure-leading channels (2a) on the pressure-leading seat (2). The outer ends of the pressure-leading pipes (251) are inserted into the corresponding pressure-leading pipe sockets (22), and the outer wall of the pressure-leading pipe (251) is welded and sealed with the pressure-leading pipe socket (22); The outlet ends of the two pressure-leading channels (2a) penetrate out from the same side of the pressure-leading seat (2). A placing sink is also provided on the pressure-leading seat (2) between the outlet ends of the two pressure-leading channels (2a). The lower part of the diaphragm pressure sensor (25) floats in the placing sink; Two parallel mounting sides are provided on the pressure-leading seat (2) in the opposite direction. The inlet ends of the two pressure-leading channels (2a) penetrate out from the two mounting sides respectively. An annular diaphragm mounting seat (21) is arranged around the inlet end of the pressure-leading channel (2a) on the mounting side. The diaphragm mounting seat (21) is an annular welding boss. An pressure-leading area is formed inside the diaphragm mounting seat (21). The port of the inlet end of the pressure-leading channel (2a) is respectively located in the corresponding pressure-leading area. The two pressure-taking seats (1) correspond to the two mounting sides one by one. An assembly plane is provided on the pressure-taking seat (1) corresponding to its mounting side. The assembly plane is attached and sealed with the corresponding mounting side. A pressure-taking area (1b) is provided on the assembly plane corresponding to the pressure-leading area. The inner end of the pressure-taking channel (1a) is connected to the pressure-taking area (1b), and the pressure-taking area (1b) is butted against the corresponding pressure-leading area; An isolation diaphragm (26) for blocking the inlet end of the pressure-leading channel (2a) is covered on the pressure-leading area, and its edge is welded and sealed with the annular welding boss.

2. The isolated pressure sensor according to claim 1, wherein: The pressure guiding seat (2) includes a mounting base (23) and a sensor mounting seat (24). The mounting base (23) is cube-shaped. Two opposite sides of the mounting base (23) form two mounting sides, and the mounting sides are vertically arranged. The sensor mounting seat (24) is fixed to the upper end surface of the mounting base (23), and the outlet ends of the two pressure guiding channels (2a) respectively penetrate out from the upper end surface of the sensor mounting seat (24). The sensor mounting seat (24) includes a horizontally placed docking plate (241). The lower surface of the docking plate (241) is fixed to the upper end surface of the mounting base (23). A docking seat (242) is fixed on the upper surface of the docking plate (241). The edge of the docking plate (241) extends outward and exceeds the docking seat (242). The pressure guiding pipe socket (22) is located on the upper surface of the docking seat (242). The outer wall of the docking seat (242) is provided with a socket thread. The outlet ends of the pressure guiding channels (2a) penetrate out from the upper end surface of the docking seat (242). The outlet ends of the two pressure guiding channels (2a) are at the same horizontal height. The projection of the connection line of the outlet ends of the two pressure guiding channels (2a) on the horizontal plane forms an angle α with the mounting side, and α = 45°.

3. The isolated pressure sensor according to claim 2, wherein: A sealing cover (3) is sleeved on the docking seat (242). The sealing cover (3) is threadedly sleeved on the docking seat (242), and the sealing cover (3) abuts against the docking plate (241) and is welded and sealed. A pressure balance channel (2b) also penetrates through the pressure guiding seat (2). The pressure balance channel (2b) is vertically arranged. The upper end of the pressure balance channel (2b) penetrates upward through the docking seat (242), and the lower end of the pressure balance channel (2b) penetrates downward through the mounting base (23). The lower end of the pressure balance channel (2b) is connected to the same pressure source as the inlet end of the pressure guiding channel (2a).

4. The isolated pressure sensor according to claim 3, characterized in that: Isolation diaphragms (26) are respectively provided at the inlet ends of the two pressure guiding channels (2a) and at the lower end of the pressure balance channel (2b). The edge of the isolation diaphragm (26) is sealed and fixed to the corresponding part of the pressure guiding seat (2). The pressure guiding channel (2a), the pressure guiding pipe (251), and the diaphragm pressure sensor (25) are internally connected. The pressure balance channel (2b) and the inside of the sealing cover (3) are internally connected. The inside and outside of the diaphragm pressure sensor (25) are isolated from each other. The pressure guiding channel (2a), the pressure guiding pipe (251), the inside of the diaphragm pressure sensor (25), the pressure balance channel (2b), and the inside of the sealing cover (3) are filled with a pressure transmission medium.

5. The isolated pressure sensor according to claim 4, wherein: A turning counterbore (2c) is provided on the bottom surface of the mounting base (23) around the lower end port of the pressure balance channel (2b). An isolation diaphragm (26) for blocking the lower end port of the pressure balance channel (2b) is provided at the bottom of the turning counterbore (2c), and its edge is welded and sealed to the bottom of the turning counterbore (2c). An end plug (27) is fixedly provided at the outer end of the steering counterbore (2c). A balanced pressure-taking area is formed between the end plug (27) and the corresponding isolation diaphragm (26). A balanced pressure-taking hole (2d) penetrates through the hole wall of the steering counterbore (2c). The inner end of the balanced pressure-taking hole (2d) is communicated with the balanced pressure-taking area. The outer end of the balanced pressure-taking hole (2d) penetrates out of the mounting base (23). The outer end of the balanced pressure-taking hole (2d) and the inlet end of any one of the pressure-inducing channels (2a) are located on the same side of the mounting base (23). A pressure-taking branch hole (1c) is further provided on the pressure-taking seat (1). One end of the pressure-taking branch hole (1c) is communicated with the pressure-taking area (1b). The other end of the balanced pressure-taking hole (2d) is communicated with the pressure-taking branch hole (1c) on any one of the pressure-taking seats (1).

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