A transmitter for measuring density and level

Abstract

The utility model discloses a kind of density and liquid level's transmitter, it is related to measuring equipment technical field.The transmitter includes probe rod, pressure sensor, waveguide silk, float ball, process joint, conditioning circuit board, outer tube and cable line;Probe rod one end is connected protective cap, the other end is connected process joint, pressure sensor is located in the probe rod near protective cap end and the sealing ring between the two, protective cap bottom surface is hollowed out;Float ball is sleeved in the probe rod outside and internal permanent magnet is fixed, its movement path is limited by process joint and protective cap;Waveguide silk is located in the probe rod, one end is equipped with damper, the other end is electrically connected with conditioning circuit board, conditioning circuit board is also electrically connected with pressure sensor and temperature sensor is arranged on it;Outer tube is connected with process joint, conditioning circuit board is placed in outer tube, cable line is electrically connected with conditioning circuit board.The transmitter can realize liquid density and liquid level measurement.

Description

Technical Field

[0001] This application relates to the field of measuring equipment technology, and more specifically, to a transmitter for measuring density and liquid level. Background Technology

[0002] In the field of process control, level sensors are one of the core sensors, and online density meters are increasingly widely used. These two sensors are often used together to meet the measurement needs of liquid level and density in open tanks. Currently, traditional density measurement mainly uses the tuning fork vibration principle and the differential pressure principle. Tuning fork density meters have poor adaptability to temperature-sensitive liquids and a narrow measurement range, making them unsuitable for measurement scenarios with large temperature fluctuations or wide measurement ranges. Differential pressure online density meters use two large diaphragms to measure the pressure difference, which are easily damaged during installation due to collisions, compression, or other external forces, increasing installation difficulty and maintenance costs. Furthermore, existing technologies often require separate dedicated sensors and transmitters for level and density measurement, leading to high initial investment costs for the process control system and requiring separate daily maintenance for each device, further increasing maintenance workload and costs. This makes it difficult to meet the development trend in process control fields towards integrated, low-cost, and low-maintenance equipment. Utility Model Content

[0003] This application provides a transmitter for measuring density and liquid level, including a probe, a pressure sensor, a waveguide wire, a float, a process connector, a conditioning circuit board, an outer tube, and a cable. One end of the probe is connected to a protective cap, and the other end is connected to the process connector. The pressure sensor is located at the end of the probe near the protective cap, and a sealing ring is provided between the pressure sensor and the probe. The bottom surface of the protective cap is hollow. The float is sleeved on the outside of the probe, and a permanent magnet is fixed inside the float. The movement path of the float is restricted by the process connector and the protective cap. The waveguide wire is located inside the probe, with a damper at one end and an electrical connection to the conditioning circuit board at the other end. The conditioning circuit board is also electrically connected to the pressure sensor, and a temperature sensor is provided on the conditioning circuit board. The outer tube is connected to the process connector, the conditioning circuit board is located inside the outer tube, and the cable is electrically connected to the conditioning circuit board.

[0004] Furthermore, the protective cap is detachably connected to the probe rod, and the protective cap is used to protect the pressure sensor's pressure-sensing diaphragm.

[0005] Furthermore, the overall density of the float is lower than the density of the liquid medium being measured, and the float can move up and down along the probe as the liquid level changes.

[0006] Furthermore, the waveguide wire is made of magnetostrictive material, and the waveguide wire and conditioning circuit board work together to form a magnetostrictive liquid level sensor.

[0007] Furthermore, the conditioning circuit board can generate current pulses and detect strain mechanical wave pulse signals generated within the waveguide wire.

[0008] Furthermore, the conditioning circuit board can perform temperature compensation on the pressure signal transmitted by the pressure sensor, and can calculate the liquid density based on the pressure signal and liquid level data.

[0009] Furthermore, the conditioning circuit board supports the RS485 Modbus_RTU standard digital communication protocol, which is used to transmit liquid level parameters, liquid bottom pressure parameters, and density parameters to the host computer.

[0010] Furthermore, the outer tube is sealed to the process connector, and the outer tube is used to protect the conditioning circuit board.

[0011] Furthermore, the pressure sensor's pressure-sensing diaphragm faces the cutout in the protective cap to sense the pressure at the bottom of the liquid.

[0012] Furthermore, the probe is sealed to the process connector to prevent liquid from entering the probe.

[0013] Beneficial effects

[0014] This transmitter for measuring density and liquid level specifically addresses the problems of poor adaptability and susceptibility to damage found in traditional density measurement equipment, as well as the high cost resulting from the need for separate equipment for level and density measurement. Specifically, it integrates the probe, pressure sensor, and waveguide wire into a single structure, eliminating the need for separate level and density measurement equipment. This significantly reduces the initial investment cost of the process control system, while also reducing the number of devices required and lowering subsequent maintenance workload and costs. The magnetostrictive level measurement structure utilizes a waveguide wire in conjunction with a float to detect liquid level, offering better adaptability to temperature-sensitive liquids compared to tuning fork density meters. It offers greater adaptability and eliminates narrow measurement range limitations, meeting the needs of more scenarios. The pressure sensor is located at the bottom of the probe and is equipped with a protective cap with a perforated bottom surface. The protective cap prevents damage to the pressure sensor's diaphragm from contact with hard objects, solving the problem of easily damaged pressure diaphragms in differential pressure online density meters due to their large size. The conditioning circuit board integrates temperature compensation, improving the accuracy of pressure signal detection. Combined with the design of converting liquid density from liquid level data, it ensures accurate density measurement. It also supports standard digital communication protocols for remote data transmission, meeting the needs of process control fields for integrated equipment, high precision, and convenient data transmission. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0016] Figure 1 A diagram of a transmitter device for measuring density and liquid level provided for an embodiment of this utility model; Figure 2 A schematic diagram of the environment for a transmitter used to measure density and liquid level, provided for an embodiment of this utility model.

[0017] Figure descriptions: 1. Protective cap; 2. Pressure sensor; 3. Damper; 4. Waveguide wire; 5. Float; 6. Permanent magnet; 7. Probe; 8. Process connector; 9. Conditioning circuit board; 10. Outer tube; 11. Cable. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0019] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0020] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0021] Example 1 refer to Figures 1-2 This utility model provides a transmitter for measuring density and liquid level, which is mainly used in open tanks containing liquids to measure liquid level and density. Its overall structure includes a probe 7, a pressure sensor 2, a waveguide wire 4, a float 5, a process connector 8, a conditioning circuit board 9, an outer tube 10, and a cable 11. The components form a complete measurement system through specific connection relationships to ensure stable dual-parameter measurement in the open tank liquid environment.

[0022] The probe rod 7 serves as the core support and protective component. One end is connected to the protective cap 1, and the other end is connected to the process connector 8. The probe rod 7 and the process connector 8 are sealed together to effectively prevent external liquids from entering the probe rod 7 and avoid internal components being corroded by liquids, thus affecting normal operation. The protective cap 1 and the probe rod 7 are detachably connected, facilitating subsequent maintenance or replacement of the pressure sensor 2. The bottom surface of the protective cap 1 features a hollow design. This design not only protects the pressure diaphragm of the pressure sensor 2 from direct contact with hard objects during installation or use, preventing damage, but also ensures that liquids from the open tank can smoothly enter the protective cap 1, enabling the pressure sensor 2 to accurately sense the pressure at the bottom of the liquid. Pressure sensor 2 is located at the end of probe 7 near protective cap 1, i.e., at the bottom of probe 7. A sealing ring is installed between pressure sensor 2 and probe 7 to form an axial sealing structure, further preventing liquid from seeping into probe 7 from the connection gap between pressure sensor 2 and probe 7, ensuring a dry working environment inside probe 7. The pressure diaphragm of pressure sensor 2 faces the cutout of protective cap 1. When the transmitter is immersed in the liquid in the open tank, the liquid comes into contact with the pressure diaphragm through the cutout of protective cap 1. Pressure sensor 2 can convert the sensed liquid pressure signal into an electrical signal, providing basic pressure data for subsequent density calculation.

[0023] A float 5 is fitted onto the outside of the probe 7. The float 5 can move up and down along the axial direction of the probe 7, and its movement path is doubly restricted by the process connector 8 and the protective cap 1. The process connector 8 is located at the upper end of the probe 7, and the protective cap 1 is located at the lower end of the probe 7. The two together form a limiting structure for the up and down movement of the float 5, preventing the float 5 from falling off the probe 7 or exceeding the effective measurement range. A permanent magnet 6 is fixedly installed inside the float 5. The permanent magnet 6 is fixedly connected to the float 5 and changes position synchronously with the movement of the float 5. The overall density of the float 5 is lower than the density of the liquid medium being measured. This design ensures that the float 5 can always float above the liquid surface in the open tank. When the liquid level changes, the float 5 can move up and down along the probe 7 synchronously with the liquid level, providing a position reference for liquid level measurement.

[0024] A waveguide wire 4 is housed inside the probe rod 7. Made of a special magnetostrictive material, the waveguide wire 4 has a damper 3 fixedly connected to one end. This damper absorbs the mechanical wave signal from the end of the waveguide wire 4, preventing mechanical wave reflection from affecting measurement accuracy. The other end of the waveguide wire 4 is electrically connected to the conditioning circuit board 9, forming a conductive circuit. The conditioning circuit board 9 is also electrically connected to the pressure sensor 2, receiving the electrical signal transmitted by the pressure sensor 2. The conditioning circuit board 9 is entirely housed inside the outer tube 10, which is connected to the process connector 8 in a sealed manner. The outer tube 10 acts as a protective structure, protecting the internal conditioning circuit board 9 from dust, water, and external impacts, ensuring it operates in a stable environment. The conditioning circuit board 9 also integrates a temperature sensor, which is integrated with the circuit board 9 to monitor the temperature of the transmitter's operating environment in real time, providing temperature data for pressure signal temperature compensation.

[0025] Cable 11 is electrically connected to conditioning circuit board 9. One end of cable 11 extends into the outer tube 10 and connects to the signal output terminal of conditioning circuit board 9, while the other end extends to the outside of the outer tube 10 for connection with the host computer to achieve data transmission and power supply. In the actual assembly process, pressure sensor 2 is first installed at the bottom of probe 7, and a sealing ring is installed at the connection between pressure sensor 2 and probe 7 to ensure axial sealing. Then, protective cap 1 is installed at the bottom end of probe 7, with the pressure-sensing diaphragm of pressure sensor 2 facing the cutout of protective cap 1. Next, waveguide wire 4 is passed through the inside of probe 7, with one end of waveguide wire 4 with damper 3 fixed at the bottom of probe 7 near pressure sensor 2, and the other end extending to the top of probe 7 and connecting to the conditioning circuit on one side of process connector 8. Connect plate 9; then insert float 5 from the bottom of probe 7, allowing float 5 to move freely along probe 7, and connect the top of probe 7 to process connector 8 to ensure a sealed connection between probe 7 and process connector 8; then fix conditioning circuit board 9 inside outer tube 10, and connect outer tube 10 to the side of process connector 8 away from probe 7 to complete the protective assembly of conditioning circuit board 9; finally connect cable 11 to conditioning circuit board 9 to ensure a stable electrical connection between cable 11 and conditioning circuit board 9, thus completing the assembly of the entire transmitter.

[0026] In practical use, the transmitter must be vertically installed on the top of the open tank, with the probe 7 inserted from the top of the open tank and extending to the bottom. The main body of the outer tube 10 and process connector 8 is fixed to the top of the open tank and not submerged in the liquid. When the transmitter starts working, the liquid in the open tank comes into contact with the pressure diaphragm of the pressure sensor 2 through the perforation of the protective cap 1. The pressure sensor 2 senses the pressure at the bottom of the liquid and converts it into an electrical signal, which is transmitted to the conditioning circuit board 9. At the same time, the float 5 floats on the liquid surface and moves up and down along the probe 7 as the liquid level changes. The conditioning circuit board 9 generates a current pulse, which is transmitted in the waveguide wire 4 and forms a circumferential magnetic field outside the waveguide wire 4. When the circumferential magnetic field intersects with the magnetic field generated by the permanent magnet 6 in the float 5, a strain mechanical wave pulse signal is generated in the waveguide wire 4 due to magnetostriction. This signal is transmitted at a fixed speed and is detected by the conditioning circuit board 9. The conditioning circuit board 9 calculates the position of the float 5 by measuring the time from the emission of the current pulse to the detection of the strain mechanical wave pulse signal, and combining this with the transmission speed of the mechanical wave, thereby determining the liquid level. Simultaneously, the conditioning circuit board 9 uses temperature data detected by the temperature sensor to perform temperature compensation on the pressure signal transmitted by the pressure sensor 2. Then, based on Archimedes' principle, and combining the calculated liquid level and the compensated pressure value, it calculates the liquid density. Finally, the conditioning circuit board 9 transmits the liquid level parameters, bottom pressure parameters, and density parameters to the host computer via cable 11 through the RS485 Modbus_RTU standard digital communication protocol, achieving real-time monitoring of the liquid level and density in the open tank.

[0027] Throughout the entire operation, probe 7 not only provides mounting support for pressure sensor 2 and waveguide wire 4, but also restricts the movement path of float 5, ensuring the stability of liquid level measurement; protective cap 1 effectively protects the pressure diaphragm of pressure sensor 2, preventing it from being damaged during installation or use; outer tube 10 provides protection for conditioning circuit board 9, ensuring stable circuit operation; the sealed connection design between each component prevents liquid from seeping into the equipment, extending the equipment's service life; and the electrical connection between conditioning circuit board 9 and each component ensures smooth signal transmission and data processing, ultimately realizing integrated liquid level and density measurement functions.

[0028] The above description is only a preferred embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made under the inventive concept of the present utility model using the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. A transmitter for measuring density and liquid level, characterized in that, The device includes a probe, a pressure sensor, a waveguide wire, a float, a process connector, a conditioning circuit board, an outer tube, and a cable. One end of the probe is connected to a protective cap, and the other end is connected to the process connector. The pressure sensor is located at the end of the probe near the protective cap, and a sealing ring is provided between the pressure sensor and the probe. The bottom surface of the protective cap is open. The float is fitted onto the outside of the probe, and a permanent magnet is fixed inside the float. The movement path of the float is restricted by the process connector and the protective cap. The waveguide wire is located inside the probe, with a damper at one end and an electrical connection to the conditioning circuit board at the other end. The conditioning circuit board is also electrically connected to the pressure sensor and has a temperature sensor. The outer tube is connected to the process connector, and the conditioning circuit board is located inside the outer tube. The cable is electrically connected to the conditioning circuit board.

2. The transmitter for measuring density and liquid level according to claim 1, characterized in that, The protective cap is detachably connected to the probe rod, and the protective cap is used to protect the pressure diaphragm of the pressure sensor.

3. The transmitter for measuring density and liquid level according to claim 1, characterized in that, The overall density of the float is lower than that of the liquid medium being measured, and the float can move up and down along the probe as the liquid level changes.

4. A transmitter for measuring density and liquid level according to claim 1, characterized in that, The waveguide wire is made of magnetostrictive material, and the waveguide wire and conditioning circuit board work together to form a magnetostrictive liquid level sensor.

5. A transmitter for measuring density and liquid level according to claim 1, characterized in that, The conditioning circuit board can generate current pulses and detect strain mechanical wave pulse signals generated within the waveguide wire.

6. A transmitter for measuring density and liquid level according to claim 1, characterized in that, The conditioning circuit board can perform temperature compensation on the pressure signal transmitted by the pressure sensor, and can calculate the liquid density based on the pressure signal and liquid level data.

7. A transmitter for measuring density and liquid level according to claim 1, characterized in that, The conditioning circuit board supports the RS485 Modbus_RTU standard digital communication protocol, which is used to transmit liquid level parameters, liquid bottom pressure parameters, and density parameters to the host computer.

8. A transmitter for measuring density and liquid level according to claim 1, characterized in that, The outer tube is sealed to the process connector and is used to protect the conditioning circuit board.

9. A transmitter for measuring density and liquid level according to claim 1, characterized in that, The pressure sensor's pressure-sensing diaphragm faces the cutout in the protective cap and is used to sense the pressure at the bottom of the liquid.

10. A transmitter for measuring density and liquid level according to claim 1, characterized in that, The probe is sealed to the process connector to prevent liquid from entering the probe.

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