A zero-drift calibration device for a pressure sensor used for water level measurement

Abstract

The present invention discloses a zero-drift calibration device for a pressure sensor used for water level measurement, including an installation housing, a sealing block and a support rod. A storage battery is fixedly installed inside the installation housing. A wireless communication module and a PLC controller main body are respectively fixedly installed on one side inside the installation housing. An ultrasonic sensor main body is fixedly installed on one side of the fixed block at the lens position. A support rod is rotatably installed inside the threaded installation block. An absolute pressure type pressure sensor main body is fixedly installed at the bottom inside the support rod. The zero-drift calibration device for the pressure sensor used for water level measurement measures through the mutual cooperation of the absolute pressure type pressure sensor main body and the ultrasonic sensor main body, avoiding the situation that the device is soaked in liquid for a long time, eliminating the fatigue problem caused by the long-term pressure on the absolute pressure type pressure sensor main body. The set stable layer makes the overall stability of the device more excellent, avoiding the reduction of the measurement data accuracy due to the influence of temperature on the overall device.

Description

Technical Field

[0001] The present invention relates to the technical field of pressure sensors, and particularly to a zero-drift calibration device for a pressure sensor used for water level measurement. Background Art

[0002] A pressure sensor is a device that can sense pressure signals and convert them into electrical signals according to a certain rule. A pressure sensor usually consists of a pressure-sensitive element and a signal processing unit. According to different types of measured pressures, pressure sensors can be divided into gauge pressure sensors, differential pressure sensors, and absolute pressure sensors. Currently, in the field of liquid level measurement, generally gauge pressure type or absolute pressure type sensors are used. The principle of measuring the liquid level by a pressure sensor is to measure the pressure of the liquid, and then calculate the height of the liquid level through the density of the liquid. However, in the actual environment, there is also an atmospheric pressure above the liquid surface, which is superimposed on the measurement result. The atmospheric pressure is not fixed, but changes slowly all the time, year after year, month after month. The basic rule of change is that it is higher in summer than in winter, higher at noon than at midnight, and the average atmospheric pressure is also related to the altitude. The higher the altitude, the thinner the air and the lower the air pressure. Instruments using gauge pressure type sensors generally use vented waterproof cables, but this method has great limitations in the application scenarios, and is prone to corrosion damage, water accumulation in the pipe, freezing, bending, or blockage caused by foreign objects entering, resulting in a shortened maintenance cycle of the instrument. Moreover, the pressure sensor needs to be placed at the lowest bottom surface of the measured liquid, and impurities such as silt carried by the liquid may block the sensor, causing the sensor to fail. At the same time, the measurement of atmospheric pressure is carried out by other instruments. This method not only requires a large investment in other instruments, but also makes the system more complex. Moreover, measuring the atmospheric pressure and the atmospheric pressure of the liquid level separately will itself generate greater systematic errors and random errors. At the same time, there is also a problem that the measurement result has a large error when the liquid level is low. Therefore, we propose a zero-drift calibration device for a pressure sensor used for water level measurement. Summary of the Invention

[0003] The purpose of the present invention is to provide a zero-drift calibration device for a pressure sensor used for water level measurement to solve the problem of a zero-drift calibration device for a pressure sensor used for water level measurement proposed in the above background art.

[0004] To achieve the above object, the present invention provides the following technical solution: A zero-drift calibration device for a pressure sensor used for water level measurement, including an installation housing, a sealing block and a support rod. On one side inside the installation housing, a storage battery is fixedly installed. On the side of the installation housing away from the storage battery, a wireless communication module and a PLC controller main body are respectively fixedly installed. At the bottom of the installation housing, a sealing block is fixedly installed. At the central position of the sealing block, a lens is inlaid and installed. On one side of the lens and at the top of the sealing block, a fixing block is fixedly installed. On one side of the fixing block at the lens position, an ultrasonic sensor main body is fixedly installed. At the bottom of the sealing block, a threaded installation block is fixedly installed. Inside the threaded installation block, a support rod is rotatably installed, and the length of the support rod is at least 5 cm greater than the measurement blind area of the ultrasonic sensor main body. At the bottom inside the support rod, an absolute pressure type pressure sensor main body extending out of the support rod is fixedly installed through a fixed buckle. The top end of the absolute pressure type pressure sensor main body is fixedly connected to a connection cable extending into the installation housing.

[0005] Preferably, two installation rings are fixedly installed on the top of the installation housing, and installation hanging ropes are fixedly installed inside the installation rings.

[0006] Preferably, internal and external threads that cooperate with each other are distributed between the outer side of the top of the support rod and the inside of the threaded installation block, and the outer side of the top of the support rod is wrapped with a polytetrafluoroethylene tape.

[0007] Preferably, the inside of the installation housing and the sealing block are both filled and installed with a stabilizing layer, and heat-conducting silica gel is evenly coated at the gaps between the stabilizing layer and the installation housing and the sealing block.

[0008] Preferably, rubber sealing gaskets are fixedly installed on both the inner and outer sides of the support rod at the installation position of the absolute pressure type pressure sensor main body.

[0009] Compared with the prior art, the beneficial effects of the present invention are as follows: The zero-drift calibration device for the pressure sensor used for water level measurement measures through the mutual cooperation of the absolute pressure type pressure sensor main body and the ultrasonic sensor main body, enabling the device to be made into an integrated instrument, ensuring that the protection ability of the installation housing can be applied to the measurement of various liquids, facilitating the installation and maintenance processes of the staff, reducing the delay time, and at the same time being able to measure the liquid level below and above the device, further avoiding the situation where the device is soaked in liquid for a long time, eliminating the fatigue problem caused by the long-term pressure on the absolute pressure type pressure sensor main body, effectively improving the overall service life of the device. The provided stabilizing layer makes the overall stability of the device more excellent, and the coating of the heat-conducting silica gel enables the heat generated by the electrical components inside the device to be better dissipated, avoiding the reduction of the measurement data accuracy due to the influence of the overall temperature of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 Schematic diagram of the overall internal structure of the present invention;

[0011] Figure 2 Schematic diagram of the bottom appearance structure of the present invention;

[0012] Figure 3 of the present invention Figure 1 Partial enlarged view of A in

[0013] In the figure: 1, mounting ring; 2, storage battery; 3, mounting housing; 301, stabilizing layer; 4, fixing block; 5, sealing block; 6, connecting cable; 7, mounting hanging rope; 8, wireless communication module; 9, PLC controller main body; 10, ultrasonic sensor main body; 11, lens; 12, support rod; 13, threaded mounting block; 14, absolute pressure type pressure sensor main body; 15, rubber sealing gasket; 16, fixing buckle. Specific embodiments

[0014] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0015] Please refer to Figures 1-3, the present invention provides a technical solution: a zero-drift calibration device for a pressure sensor used for water level measurement, including an installation housing 3, a sealing block 5 and a support rod 12. On one side inside the installation housing 3, a storage battery 2 is fixedly installed. The storage battery 2 can be a storage battery of the 12V 8AH model. The fixed installation of the storage battery 2 provides electrical energy for each electrical component inside the device, enabling the overall device to maintain operation, effectively improving the simplicity of the device during operation. On the side inside the installation housing 3 away from the storage battery 2, a wireless communication module 8 and a plc controller main body 9 are respectively fixedly installed. The wireless communication module 8 can be a wireless communication module of the USR-GPRS232-730 model. The wireless communication module 8 can transmit the data measured by the device to an external receiving end in real time, enabling the staff to master the detection data of the device at any time. The plc controller main body 9 can be a plc controller main body of the OSM-16J PLC-DC model. At the bottom of the installation housing 3, a sealing block 5 is fixedly installed. The sealing block 5 is fixedly installed at the bottom of the installation housing 3 through installation screws. At the same time, a sealing ring is adhesively installed between the installation housing 3 and the sealing block 5, ensuring the dryness inside the device and preventing external water sources from entering and damaging the device. At the central position of the sealing block 5, a lens 11 is inlaid. The lens 11 ensures that the ultrasonic waves emitted by the ultrasonic sensor main body 10 can penetrate normally. At the same time, sealant is evenly sprayed at the connection between the lens 11 and the sealing block 5. On one side of the lens 11, at the top of the sealing block 5, a fixing block 4 is fixedly installed. The fixing block 4 is welded to the top of the sealing block 5. On one side of the fixing block 4 at the position of the lens 11, an ultrasonic sensor main body 10 is fixedly installed. The ultrasonic sensor main body 10 is fixedly connected to the fixing block 4 through installation screws, and at the same time, it is convenient for the staff to select an ultrasonic sensor main body 10 with a suitable range according to the actual operation situation. The ultrasonic sensor main body 10 can be an ultrasonic sensor main body of the QT50U model. At the bottom of the sealing block 5, a threaded installation block 13 is fixedly installed. The threaded installation block 13 is welded to the bottom of the sealing block 5. Inside the threaded installation block 13, a support rod 12 is rotatably installed, and the length of the support rod 12 is at least 5 cm greater than the measurement blind area of the ultrasonic sensor main body 10. At the bottom inside the support rod 12, an absolute pressure type pressure sensor main body 14 extending out of the support rod 12 is fixedly installed through a fixed buckle 16. The absolute pressure type pressure sensor main body 14 can be an absolute pressure type pressure sensor main body of the HBM P3IC / P3ICP-10bar model. The top end of the absolute pressure type pressure sensor main body 14 is fixedly connected to a connection cable 6 extending into the installation housing 3. All the electrical components inside the device are electrically connected through wires.

[0016] In the present invention: Two mounting rings 1 are fixedly installed at the top of the mounting housing 3, and a mounting hanging rope 7 is fixedly installed inside the mounting ring 1. The fixed installation of the mounting ring 1 and the mounting hanging rope 7 facilitates the use process of the staff, facilitates the staff to control the depth of the device in water, and ensures the safety of the overall device in water.

[0017] In the present invention: External and internal threads that cooperate with each other are distributed between the outer side of the top of the support rod 12 and the inside of the threaded mounting block 13, and a polytetrafluoroethylene tape is wrapped around the outer side of the top of the support rod 12. The rotational installation between the support rod 12 and the threaded mounting block 13 reduces the maintenance time of the absolute pressure type pressure sensor main body 14 for the staff. At the same time, the wrapping installation of the polytetrafluoroethylene tape effectively improves the sealing performance inside the support rod 12 and ensures the use safety of the overall device.

[0018] In the present invention: The inside of the mounting housing 3 and the sealing block 5 are both filled and installed with a stabilizing layer 301, and heat-conducting silicone is evenly coated at the gaps between the stabilizing layer 301 and the mounting housing 3 and the sealing block 5. The filling and installation of the stabilizing layer 301 makes the overall stability of the device better. The coating of the heat-conducting silicone enables the heat generated by the electrical components inside the device to be better conducted to the mounting housing 3 and then dissipated in water, avoiding the reduction of the measurement data accuracy due to the influence of temperature on the overall device.

[0019] In the present invention: Rubber sealing washers 15 are fixedly installed on both the inner and outer sides of the support rod 12 at the installation position of the absolute pressure type pressure sensor main body 14. The rubber sealing washers 15 further ensure the sealing performance at the installation position of the absolute pressure type pressure sensor main body 14, prevent external water from entering the inside of the support rod 12 and damaging the absolute pressure type pressure sensor main body 14, and effectively improve the service life of the overall device.

[0020] Working principle: Different sensors are used for measurement according to different liquid levels of the device at the bottom of the water. When the liquid level is low, the ultrasonic sensor main body 10 is used for measurement. Through the measurement results, it can be obtained whether the water level has reached the position where the absolute pressure sensor main body 14 is located. Before the liquid level reaches the absolute pressure sensor main body 14, the absolute pressure sensor main body 14 can measure the atmospheric pressure and record it. Under this condition, the measurement errors caused by factors such as temperature and climate are compensated. When the liquid level has reached above the absolute pressure sensor main body 14 and has not entered the measurement blind area of the ultrasonic sensor main body 10, the device reads the measurement results of both the ultrasonic sensor main body 10 and the absolute pressure sensor main body 14 simultaneously, and calibrates the measurement results of the absolute pressure sensor main body 14 based on the liquid level of the ultrasonic sensor main body 10. Under this condition, not only can the atmospheric pressure be compensated, but also the measurement errors caused by reasons such as fatigue of the absolute pressure sensor main body 14 can be eliminated. When the liquid level is higher than the measurement blind area of the ultrasonic sensor main body 10, the absolute pressure sensor main body 14 is used alone for measurement. Through this solution, the immersion time of the absolute pressure sensor main body 14 in water can be reduced, the dependence on the measured water quality and the use environment can be reduced, and the measurement range of the water level can be extended.

[0021] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device.

[0022] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A zero-drift calibration device for a pressure sensor used for water level measurement, comprising an installation housing (3), a sealing block (5) and a support rod (12). Characterized in that: On one side inside the installation housing (3), a storage battery (2) is fixedly installed. On the side of the installation housing (3) away from the storage battery (2), a wireless communication module (8) and a PLC controller main body (9) are respectively fixedly installed. At the bottom of the installation housing (3), a sealing block (5) is fixedly installed. At the central position of the sealing block (5), a lens (11) is inlaid and installed. On one side of the lens (11), at the top of the sealing block (5), a fixing block (4) is fixedly installed. On one side of the fixing block (4) at the position of the lens (11), an ultrasonic sensor main body (10) is fixedly installed. At the bottom of the sealing block (5), a threaded installation block (13) is fixedly installed. Inside the threaded installation block (13), a support rod (12) is rotatably installed, and the length of the support rod (12) is at least 5 cm greater than the measurement blind area of the ultrasonic sensor main body (10). At the bottom inside the support rod (12), an absolute pressure type pressure sensor main body (14) extending out of the support rod (12) is fixedly installed through a fixing buckle (16). The top end of the absolute pressure type pressure sensor main body (14) is fixedly connected to a connection cable (6) extending into the installation housing (3). Between the outer side of the top of the support rod (12) and the inside of the threaded installation block (13), internal and external threads that cooperate with each other are distributed, and the outer side of the top of the support rod (12) is wrapped with a polytetrafluoroethylene tape. Both the inside of the installation housing (3) and the sealing block (5) are filled and installed with a stabilizing layer (301), and heat-conducting silicone is evenly coated at the gaps between the stabilizing layer (301) and the installation housing (3) and the sealing block (5). Rubber sealing washers (15) are fixedly installed on both the inner and outer sides of the support rod (12) at the installation position of the absolute pressure type pressure sensor main body (14).

2. A zero-drift calibration device for a pressure sensor used for water level measurement according to claim 1, Characterized in that: Two sets of installation rings (1) are fixedly installed on the top of the installation housing (3), and an installation hanging rope (7) is fixedly installed inside the installation rings (1).

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