Pressure-resistant deep sea pH sensor based on ion sensitive field effect transistor

Abstract

The utility model discloses a pressure-resistant deep sea pH sensor based on an ion sensitive field effect transistor, which relates to the technical field of pH sensors and comprises a detection tube, a detection circuit board is arranged in the detection tube, a bottom tube is sleeved at the lower end of the outer wall of the detection tube through threads, and a salt bridge is arranged at the lower end of the inner wall of the detection tube. The bottom of the salt bridge is in contact fit with the bottom of the inner wall of the bottom pipe, a chip fixing pipe is fixedly embedded in the salt bridge, the upper end of the detection pipe is sleeved with a top pipe through threads, the upper end of the detection circuit board is located in the top pipe, the inner wall of the detection pipe is filled with sealant, and the outer side of the chip fixing pipe is sleeved with the sealant in a sealed mode. An external reference solution is filled between the chip fixing tube and the detection tube, and an electrode is connected to the interior of the external reference solution. The ion-sensitive field effect transistor is used for replacing a traditional glass electrode, so that the ion-sensitive field effect transistor-based seawater pH detection device has better voltage withstanding characteristic and can realize seawater pH detection under the condition of deep sea high pressure.

Description

Technical Field

[0001] This utility model relates to the field of pH sensor technology, specifically to a pressure-resistant deep-sea pH sensor based on an ion-sensitive field-effect transistor. Background Technology

[0002] pH is a parameter that reflects the acidity or alkalinity of seawater. Currently, pH composite electrodes composed of glass electrodes and reference electrodes are commonly used to measure the pH value of seawater. However, since the pH glass electrode is composed of a glass film and is spherical in shape, and the film is filled with 0.1 mol / L hydrochloric acid and silver chloride electrodes, it is easily damaged by compression under the high pressure of the deep sea. Therefore, it is difficult to use in the deep sea at depths exceeding 100 meters.

[0003] This invention uses an ion-sensitive field-effect transistor to replace the traditional glass bulb, which has better measurement response speed and measurement accuracy than glass electrodes. It is suitable for profile monitoring and rapid monitoring of pH in the deep sea, and is also suitable for applications in industries such as food and pharmaceutical where glass electrodes are not applicable. Utility Model Content

[0004] In view of the problems existing in the pressure-resistant deep-sea pH sensor based on ion-sensitive field-effect transistors, this utility model is proposed.

[0005] Therefore, the purpose of this invention is to provide a pressure-resistant deep-sea pH sensor based on an ion-sensitive field-effect transistor, which solves the problem that traditional pH glass electrodes are composed of glass films, and the measuring substances filled inside are easily squeezed and damaged under the high pressure of deep sea conditions.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] A pressure-resistant deep-sea pH sensor based on an ion-sensitive field-effect transistor includes a detection tube with a detection circuit board inside. A bottom tube is threaded onto the lower end of the outer wall of the detection tube. A salt bridge is located at the lower end of the inner wall of the detection tube, with its bottom contacting the bottom of the inner wall of the bottom tube. A chip fixing tube is fixedly embedded inside the salt bridge. A top tube is threaded onto the upper end of the detection tube, with the upper end of the detection circuit board located inside the top tube. The inner wall of the detection tube is filled with sealant, which is sealed onto the outside of the chip fixing tube. An external reference solution is filled between the chip fixing tube and the detection tube, and an electrode is connected inside the external reference solution.

[0008] Preferably, the upper end of the inner wall of the jacking pipe is provided with a sealing thread, and the upper end of the inner wall of the jacking pipe is connected to a water-sealing connector through the sealing thread.

[0009] Preferably, the external reference solution is a 3 mol / L KCl solution.

[0010] Preferably, the electrode is a silver-silver chloride electrode.

[0011] Furthermore, a plurality of limiting protrusions are fixedly provided at the lower end of the inner wall of the detection tube, and the limiting protrusions are in contact with the top of the salt bridge.

[0012] Preferably, the top of the detection circuit board is provided with a source and a drain.

[0013] The technical effects and advantages provided by this utility model in the above technical solution are as follows:

[0014] 1. This utility model, through the inclusion of a detection tube, bottom tube, top tube, salt bridge, detection circuit board, chip fixing tube, sealant, and external reference solution, uses an ion-sensitive field-effect transistor to replace the traditional glass electrode, exhibiting better pressure resistance characteristics. It can realize the detection of seawater pH under high pressure conditions in the deep sea, expanding the unsuitable scenarios of the original glass pH composite electrode, and is of great significance for carrying out deep-sea exploration and deep-sea marine life protection. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this utility model. For those skilled in the art, other drawings can be obtained based on these drawings.

[0016] Figure 1 This is a schematic diagram of the structure of this utility model;

[0017] Figure 2 For the present utility model Figure 1 Enlarged schematic diagram of part A;

[0018] Figure 3 This invention relates to the pH measurement principle of the ion-sensitive field-effect transistor.

[0019] Explanation of reference numerals in the attached figures:

[0020] 1. Detection tube; 2. Detection circuit board; 3. Bottom tube; 4. Salt bridge; 5. Chip fixing tube; 6. Top tube; 7. Sealant; 8. External reference solution; 9. Electrode; 10. Water-sealed connector; 11. Limiting bump; 12. Source electrode; 13. Drain electrode. Detailed Implementation

[0021] To enable those skilled in the art to better understand the technical solution of this utility model, the present utility model will be further described in detail below with reference to the accompanying drawings.

[0022] This utility model discloses a pressure-resistant deep-sea pH sensor based on an ion-sensitive field-effect transistor.

[0023] This utility model provides, for example Figure 1-3 The pressure-resistant deep-sea pH sensor based on an ion-sensitive field-effect transistor shown includes a detection tube 1, a detection circuit board 2 inside the detection tube 1, a source electrode 12 and a drain electrode 13 on the top of the detection circuit board 2, a bottom tube 3 threadedly fitted to the lower end of the outer wall of the detection tube 1, a salt bridge 4 at the lower end of the inner wall of the detection tube 1, the bottom of the salt bridge 4 contacting and fitting with the bottom of the inner wall of the bottom tube 3, a chip fixing tube 5 fixedly embedded inside the salt bridge 4, a top tube 6 threadedly fitted to the upper end of the detection tube 1, a sealing thread on the upper end of the inner wall of the top tube 6, and a water-sealing connector 10 connected to the upper end of the inner wall of the top tube 6 through the sealing thread.

[0024] The upper end of the detection circuit board 2 is located inside the top tube 6. The inner wall of the detection tube 1 is filled with sealant 7. The sealant 7 is sealed on the outside of the chip fixing tube 5. An external reference solution 8 is filled between the chip fixing tube 5 and the detection tube 1. The external reference solution 8 is a 3 mol / L KCl solution. An electrode 9 is connected inside the external reference solution 8. The electrode 9 is a silver-silver chloride electrode.

[0025] Before using the pH sensor, an ion-sensitive field-effect transistor PCB board is selected and encapsulated in the detection tube 1. The detection circuit board 2 is fixed by the chip fixing tube 5. Then, a salt bridge 4 is set at the lower end of the chip fixing tube 5, and the position of the salt bridge 4 is restricted by the bottom tube 3. Then, the external reference solution 8 is filled into the detection tube 1 and sealed and fixed with sealant 7. Finally, the top tube 6 is set at the top of the detection tube 1 by threaded connection, and the water seal connector 10 is sealed and fixed. At this time, the sensor is in contact.

[0026] When performing pH detection, the lower part of the sensor is in contact with the liquid to be tested via the salt bridge 4. By applying a certain voltage between the source electrode 12 and the drain electrode 13, when the hydrogen ion concentration in the external reference solution 8 changes, the voltage between the electrode 9 and the source electrode 12 will change with the pH and follow the Nernst equation. Therefore, the pH of the solution to be tested can be accurately measured by measuring the potential difference between the electrode 9 and the source electrode.

[0027] Meanwhile, a data storage unit and a lithium battery unit are placed inside the jacking pipe 6 to seal the jacking pipe 6, so that it can independently complete power supply and data storage without relying on external power supply, thus improving the application scenarios of the sensor.

[0028] In order to effectively fix the position of salt bridge 4, such as Figure 2As shown, multiple limiting protrusions 11 are fixedly provided at the lower end of the inner wall of the detection tube 1, and the limiting protrusions 11 are in contact with the top of the salt bridge 4.

[0029] The position of the salt bridge 4 can be fixed by the bidirectional support of the limiting protrusion 11 and the bottom of the bottom pipe 3, so as to avoid the salt bridge from shifting due to water pressure and ensure the stable operation of pH testing.

[0030] The foregoing description only illustrates certain exemplary embodiments of the present invention. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A pressure-resistant deep-sea pH sensor based on an ion-sensitive field-effect transistor, comprising a detection tube (1), characterized in that, The detection tube (1) is provided with a detection circuit board (2) inside. The lower end of the outer wall of the detection tube (1) is fitted with a bottom tube (3) through a thread. The lower end of the inner wall of the detection tube (1) is provided with a salt bridge (4). The bottom of the salt bridge (4) is in contact with the bottom of the inner wall of the bottom tube (3). A chip fixing tube (5) is fixedly embedded inside the salt bridge (4). The upper end of the detection tube (1) is fitted with a top tube (6) through a thread. The upper end of the detection circuit board (2) is located inside the top tube (6). The inner wall of the detection tube (1) is filled with sealant (7). The sealant (7) is sealed on the outside of the chip fixing tube (5). An external reference solution (8) is filled between the chip fixing tube (5) and the detection tube (1). An electrode (9) is connected inside the external reference solution (8).

2. The pressure-resistant deep-sea pH sensor based on an ion-sensitive field-effect transistor according to claim 1, characterized in that, The upper end of the inner wall of the jacking pipe (6) is provided with a sealing thread, and the upper end of the inner wall of the jacking pipe (6) is connected to a water-sealing connector (10) through the sealing thread.

3. The pressure-resistant deep-sea pH sensor based on an ion-sensitive field-effect transistor according to claim 1, characterized in that, The external reference solution (8) is a 3 mol / L KCl solution.

4. The pressure-resistant deep-sea pH sensor based on an ion-sensitive field-effect transistor according to claim 1, characterized in that, The electrode (9) is a silver-silver chloride electrode.

5. The pressure-resistant deep-sea pH sensor based on an ion-sensitive field-effect transistor according to claim 1, characterized in that, The lower end of the inner wall of the detection tube (1) is fixedly provided with a plurality of limiting protrusions (11), and the limiting protrusions (11) are in contact with the top of the salt bridge (4).

6. The pressure-resistant deep-sea pH sensor based on an ion-sensitive field-effect transistor according to claim 1, characterized in that, The top of the detection circuit board (2) is provided with a source (12) and a drain (13).

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