阅读说明：本技术 一种测量液位的数字压力传感器及其工作方法 (Digital pressure sensor for measuring liquid level and working method thereof ) 是由 陈建华 余巍 李春霞 余溶芳 机麗美 于 2019-09-30 设计创作，主要内容包括：本发明实施例公开了一种测量液位的数字压力传感器及其工作方法,所述测量液位的数字压力传感器包括：微型压力传感器芯片、数字调理芯片、电路板和金属屏蔽罩,所述微型压力传感器和数字调理芯片并排安装在电路板上,所述金属屏蔽罩安装在电路板的两端,金属屏蔽罩的端部设有气帽接口,电路板上方的金属屏蔽罩内填充柔性硅胶胶水。本发明解决了解决现有液位测量装置测量精度低、不能防水防油的问题。(The embodiment of the invention discloses a digital pressure sensor for measuring liquid level and a working method thereof, wherein the digital pressure sensor for measuring liquid level comprises the following components: miniature pressure sensor chip, digital chip, circuit board and metallic shield cover of recuperating, miniature pressure sensor and digital chip of recuperating are installed on the circuit board side by side, the metallic shield cover is installed at the both ends of circuit board, and the tip of metallic shield cover is equipped with the gas cap interface, packs flexible silica gel glue in the metallic shield cover of circuit board top. The invention solves the problems that the existing liquid level measuring device has low measuring precision and can not prevent water and oil.)

1. A digital pressure sensor for measuring a liquid level, the digital pressure sensor for measuring a liquid level comprising: miniature pressure sensor chip, digital chip, circuit board and metallic shield cover of recuperating, miniature pressure sensor and digital chip of recuperating are installed on the circuit board side by side, the metallic shield cover is installed at the both ends of circuit board, and the tip of metallic shield cover is equipped with the gas cap interface, packs flexible silica gel glue in the metallic shield cover of circuit board top.

2. The digital pressure sensor for measuring liquid level according to claim 1, wherein the micro pressure sensor chip comprises a pressure membrane, a sensing circuit is integrated on the upper surface of the pressure membrane, and a circular through hole is formed on a circuit board at the bottom of the pressure membrane.

3. The digital pressure sensor for measuring liquid level according to claim 1, wherein the digital conditioning chip is connected to the micro pressure sensor chip, the digital conditioning chip is integrated with an amplifier, an oscillation isolator, an analog-to-digital converter, a memory and a timer, and the digital conditioning chip is programmed with a sensor linearity, temperature coefficient and pressure sensitivity compensation coefficient calculation program.

4. The digital pressure sensor for measuring liquid level according to claim 1, wherein the metal shielding case comprises an upper metal shielding case and a lower metal shielding case, the upper metal shielding case is cylindrical with openings at two ends, the bottom of the upper metal shielding case is connected with the circuit board through glue, the micro pressure sensor chip and the digital conditioning chip are located in the upper metal shielding case, the lower metal shielding case is connected with the circuit board through glue, the top opening of the lower metal shielding case is aligned with the circular through hole formed in the circuit board, and the bottom of the lower metal shielding case is provided with an opening.

5. The digital pressure sensor for measuring liquid level according to claim 4, wherein the top of the upper metal shielding case is provided with an upper air cap interface, the upper air cap interface at the top of the upper metal shielding case is used for injecting flexible silica gel glue into the metal shielding case for curing, so that the flexible silica gel glue seals the micro pressure sensor chip and the digital conditioning chip, the bottom of the lower metal shielding case is provided with a lower air cap interface, the lower metal shielding case is communicated with the circular through hole on the circuit board, and both the upper air cap interface and the lower air cap interface can be connected with an external liquid pipeline.

6. The digital pressure sensor for measuring liquid level according to claim 1, wherein the circuit board is provided with a power line interface, a control line interface, a data line interface and a grounding line interface, the device connection adopts patch connection or manual welding, and the side edge of the circuit board is provided with a reinforced bonding pad.

7. The digital pressure sensor for measuring liquid level according to claim 6, wherein the power line interface of the circuit board is connected with a power supply for supplying power to the micro pressure sensor chip and the digital conditioning chip, the data line interface is connected with a data line for outputting the digital conditioning result, and the ground line interface is connected with a ground line for grounding.

8. A method of operating a digital pressure transducer for measuring liquid level according to any of claims 1-7, characterized in that the method is:

switching on a power supply, and supplying power to the miniature pressure sensor chip and the digital conditioning chip through a power line interface of the circuit board;

the upper air cap interface or the lower air cap interface is connected with an external liquid pipeline, when the upper air cap interface is connected with the external liquid pipeline, liquid enters the upper metal shielding cover and contacts with the cured flexible silica gel glue, the pressure is transmitted to a pressure membrane of the miniature pressure sensor chip through the flexible silica gel glue, and the lower air cap interface is used as a reference interface;

the lower air cap interface is connected with an external liquid pipeline, liquid enters the lower metal shielding cover and is contacted with the bottom of a pressure membrane of the miniature pressure sensor chip to directly transmit pressure to the pressure membrane, and the upper air cap interface is used as a reference interface;

the micro pressure sensor chip amplifies the pressure signal through a Wheatstone bridge, performs temperature compensation in the range of-25 ℃ to 125 ℃, and transmits the signal to the digital conditioning chip;

calculating pressure signals by a sensor linearity, temperature coefficient and pressure sensitivity compensation coefficient calculation program burnt in the digital conditioning chip, and directly outputting a pressure value with the unit of pa;

and the data line is connected with the data line through a data line interface on the circuit board, and the calculation result of the digital conditioning chip is output and directly applied.

Technical Field

The embodiment of the invention relates to the technical field of liquid level measurement, in particular to a digital pressure sensor for measuring liquid level and a working method thereof.

Background

In the fields of modern industry, building, address survey and medical treatment, liquid level measurement is involved, and the traditional liquid level measurement adopts a mechanical electrical transmission mode and a radar measurement device, wherein a buoy which can float along with the liquid level is arranged on the surface of the liquid level in the mechanical electrical transmission mode, the buoy generates electric signals with different magnitudes when moving to different positions, and finally the electric signals are converted into liquid level signals; the radar measuring device calculates the actual liquid level through the reflection time difference of radar waves, and the measuring precision is low.

At present, sectional type tests are generally carried out on electric liquid level measurement in the market by using a Hall switch, and some problems exist, firstly, a refined test value cannot be provided, and only 1/5, 2/5, 3/5, 4/5 and 5/5 can be measured according to a designed section position, such as 5 sections, which is equivalent to a switching value; secondly, the rear end application mechanical design structure is not flexible, the space of the internal liquid level cavity is limited too much when the product is upgraded, and the product in the market has no too much free space in volume; moreover, the structural design cost is too high, the hall switch is originally applied to a semiconductor, a support body is required when the hall switch is completely installed in water, if the hall switch is more precise, more hall switches are used, more protection structures are required outside, and the cost required in the assembling process is higher.

Disclosure of Invention

Therefore, the embodiment of the invention provides a digital pressure sensor for measuring liquid level and a working method thereof, which aim to solve the problems that the existing liquid level measuring device is low in measuring precision and cannot prevent water and oil.

In order to achieve the above object, the embodiments of the present invention provide the following technical solutions:

according to a first aspect of embodiments of the present invention, there is disclosed a digital pressure sensor for measuring a liquid level, the digital pressure sensor for measuring a liquid level comprising: miniature pressure sensor chip, digital chip, circuit board and metallic shield cover of recuperating, miniature pressure sensor and digital chip of recuperating are installed on the circuit board side by side, the metallic shield cover is installed at the both ends of circuit board, and the tip of metallic shield cover is equipped with the gas cap interface, packs flexible silica gel glue in the metallic shield cover of circuit board top.

Furthermore, the miniature pressure sensor chip comprises a pressure membrane, a sensing circuit is integrated on the upper surface of the pressure membrane, and a circular through hole is formed in a circuit board at the bottom of the pressure membrane.

Furthermore, the digital conditioning chip is connected with the miniature pressure sensor chip, an amplifier, an oscillation isolator, an analog-to-digital converter, a memory and a timer are integrated in the digital conditioning chip, and a sensor linearity, temperature coefficient and pressure sensitivity compensation coefficient calculation program is burnt in the digital conditioning chip.

Furthermore, the metal shielding cover comprises an upper metal shielding cover and a lower metal shielding cover, the upper metal shielding cover is cylindrical, two ends of the upper metal shielding cover are open, the bottom of the upper metal shielding cover is connected with the circuit board through glue, the miniature pressure sensor chip and the digital conditioning chip are located in the upper metal shielding cover, the lower metal shielding cover is connected with the circuit board through glue, the top opening of the lower metal shielding cover is aligned to the circular through hole formed in the circuit board, and an opening is formed in the bottom of the lower metal shielding cover.

Further, go up the metal shield cover top and be provided with the gas cap interface, go up the gas cap interface through last metal shield cover top and pour into flexible silica gel glue into in to the metal shield cover and solidify, make the sealed miniature pressure sensor chip of flexible silica gel glue and digital conditioning chip, metal shield cover bottom is provided with down the gas cap interface down, and lower metal shield cover is linked together with the circular through-hole on the circuit board, go up the gas cap interface and all can connect outside liquid pipeline with lower gas cap interface.

Furthermore, the circuit board is provided with a power line interface, a control line interface, a data line interface and a grounding line interface, the device connection adopts patch connection or manual welding, and the side edge of the circuit board is provided with a reinforcing bonding pad.

Furthermore, a power line interface of the circuit board is connected with a power supply to supply power for the miniature pressure sensor chip and the digital conditioning chip, a data line interface is connected with a data line to output a digital conditioning result, and a ground wire interface is connected with a ground wire to be grounded.

According to a second aspect of the embodiments of the present invention, a method for operating a digital pressure sensor for measuring a liquid level is disclosed, the method comprising:

switching on a power supply, and supplying power to the miniature pressure sensor chip and the digital conditioning chip through a power line interface of the circuit board;

the upper air cap interface or the lower air cap interface is connected with an external liquid pipeline, when the upper air cap interface is connected with the external liquid pipeline, liquid enters the upper metal shielding cover and contacts with the cured flexible silica gel glue, the pressure is transmitted to a pressure membrane of the miniature pressure sensor chip through the flexible silica gel glue, and the lower air cap interface is used as a reference interface;

the lower air cap interface is connected with an external liquid pipeline, liquid enters the lower metal shielding cover and is contacted with the bottom of a pressure membrane of the miniature pressure sensor chip to directly transmit pressure to the pressure membrane, and the upper air cap interface is used as a reference interface;

the micro pressure sensor chip amplifies the pressure signal through a Wheatstone bridge, performs temperature compensation in the range of-25 ℃ to 125 ℃, and transmits the signal to the digital conditioning chip;

calculating pressure signals by a sensor linearity, temperature coefficient and pressure sensitivity compensation coefficient calculation program burnt in the digital conditioning chip, and directly outputting a pressure value with the unit of pa;

and the data line is connected with the data line through a data line interface on the circuit board, and the calculation result of the digital conditioning chip is output and directly applied.

The embodiment of the invention has the following advantages:

the embodiment of the invention discloses a digital pressure sensor for measuring liquid level and a working method thereof, wherein liquid level information is calculated by measuring pressure values through a micro pressure sensor chip and a digital conditioning chip, circuit parts on the micro pressure sensor and the digital conditioning chip are sealed by flexible silica gel glue, water and oil resistance is realized, the circuit parts are protected from short circuit, the circuit board is provided with the upper metal shielding cover and the lower metal shielding cover to shield interference signals, the circular through hole arranged on the circuit board can enable the micro pressure sensor chip to be in relative air pressure balance, the micro pressure sensor chip is not influenced by external atmospheric pressure fluctuation, errors are reduced, the measurement accuracy is improved, in consideration of power consumption, pressure measurement precision and real-time performance of dynamic liquid level, the small-size design can realize automatic production in production and manufacturing and simultaneously support the simplicity of rear-end installation. The front-end production efficiency of the pressure sensor and the compatibility of rear-end finished product installation are greatly improved, the die sinking cost of a rear-end client is saved, more form application designs of a user are facilitated, and an industry solution is more flexibly provided.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. It should be apparent that the drawings in the following description are merely exemplary, and that other embodiments can be derived from the drawings provided by those of ordinary skill in the art without inventive effort.

The structures, ratios, sizes, and the like shown in the present specification are only used for matching with the contents disclosed in the specification, so as to be understood and read by those skilled in the art, and are not used to limit the conditions that the present invention can be implemented, so that the present invention has no technical significance, and any structural modifications, changes in the ratio relationship, or adjustments of the sizes, without affecting the effects and the achievable by the present invention, should still fall within the range that the technical contents disclosed in the present invention can cover.

FIG. 1 is a block diagram of a digital pressure sensor for measuring liquid level according to an embodiment of the present invention;

FIG. 2 is a cross-sectional view of a digital pressure sensor for measuring fluid level provided by an embodiment of the present invention;

FIG. 3 is a top view of a digital pressure sensor for measuring fluid level according to an embodiment of the present invention;

FIG. 4 is a bottom block diagram of a digital pressure sensor for measuring liquid level according to an embodiment of the present invention;

fig. 5 is a circuit diagram of a digital pressure sensor for measuring liquid level according to an embodiment of the present invention.

In the figure: the pressure sensor comprises a 1-miniature pressure sensor chip, a 2-digital conditioning chip, a 3-circuit board, a 4-pressure membrane, a 5-amplifier, a 6-oscillation isolator, a 7-analog-to-digital converter, an 8-memory, a 9-timer, a 10-upper metal shielding cover, a 11-lower metal shielding cover, a 12-circular through hole, a 13-upper air cap interface and a 14-lower air cap interface.

Detailed Description

The present invention is described in terms of particular embodiments, other advantages and features of the invention will become apparent to those skilled in the art from the following disclosure, and it is to be understood that the described embodiments are merely exemplary of the invention and that it is not intended to limit the invention to the particular embodiments disclosed. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.