Liquid specific gravity measuring device

Abstract

The present invention discloses a liquid specific gravity measuring device, comprising: a measuring platform fixed on the side wall of a container, a first through hole and a second through hole are arranged on the measuring platform, a first measuring rod and a second measuring rod of the same length and cross section are respectively extended from top to bottom into the measured liquid through the first through hole and the second through hole and freely suspended in the measured liquid, a first displacement sensor and a second displacement sensor for detecting up and down movement are respectively arranged beside the first through hole and the second through hole; the weight of the first measuring rod is 1.5 to 3 times the weight of the second measuring rod; the signals of the first displacement sensor and the second displacement sensor are connected to a PLC control module, and the PLC control module includes a data acquisition unit, a central processing unit, a storage unit, a power supply unit and a display input unit. The present invention can realize the real-time and accurate measurement of the liquid specific gravity, and greatly improve the work efficiency.

Description

Technical Field

[0001] The present invention relates to a specific gravity measuring device, and more particularly, to a device for measuring the specific gravity of liquid in real time. Background Art

[0002] In the chemical industry, it is often necessary to accurately measure the specific gravity of the mixed liquid in the reaction tank to determine the reaction conditions. Most of the devices used in the prior art for accurately measuring the specific gravity of liquids are relatively expensive and cannot be displayed in real time, and the operation is relatively cumbersome.

[0003] CN105372152 discloses an alcohol specific gravity measuring instrument, including a glass specific gravity meter, a grating ruler sensor and a measurement and control system. However, in this solution, zeroing needs to be performed before measurement, and the system efficiency is relatively low. Summary of the invention

[0004] An object of the present invention is to solve at least the above problems and / or disadvantages and to provide at least the advantages which will be described hereinafter.

[0005] In order to achieve these purposes and other advantages according to the present invention, a liquid specific gravity measuring device is provided, comprising: a measuring platform fixed on the side wall of a container, the measuring platform is parallel to the upper surface of the measured liquid, a first through hole and a second through hole are arranged on the measuring platform, a first measuring rod and a second measuring rod with the same length and cross-section respectively extend from top to bottom into the measured liquid through the first through hole and the second through hole and freely suspend in the measured liquid, a first displacement sensor for detecting the up and down movement of the first measuring rod is arranged next to the first through hole, and a second displacement sensor for detecting the up and down movement of the second measuring rod is arranged next to the second through hole; the weight of the first measuring rod is 1.5 to 3 times the weight of the second measuring rod; the signals of the first displacement sensor and the second displacement sensor are connected to a PLC control module, and the PLC control module includes a data acquisition unit, a central processing unit, a storage unit, a power supply unit and a display input unit.

[0006] Preferably, the first displacement sensor is a first grating scale displacement sensor, the scale grating of the first grating scale displacement sensor is vertically distributed on the first measuring rod, and the grating reading head of the first grating scale displacement sensor is arranged beside the first through hole; the second displacement sensor is a second grating scale displacement sensor, the scale grating of the second grating scale displacement sensor is vertically distributed on the second measuring rod, and the grating reading head of the second grating scale displacement sensor is arranged beside the second through hole.

[0007] Preferably, the first measuring rod and the second measuring rod are identical cylindrical or polygonal columns.

[0008] Preferably, the first measuring rod and the second measuring rod are made of polytetrafluoroethylene or glass.

[0009] Preferably, the first measuring rod and the second measuring rod are hollow inside.

[0010] Preferably, a limiter is provided at the top end of the first measuring rod and the second measuring rod.

[0011] Preferably, the weight of the first measuring rod is twice the weight of the second measuring rod.

[0012] Preferably, the display input unit is a handwriting display screen.

[0013] The present invention includes at least the following beneficial effects: since the displacement sensor is used to accurately measure the displacement of the first measuring rod and the second measuring rod, and the data is collected and calculated through the PLC system, the real-time and accurate measurement of the liquid specific gravity can be achieved, which greatly improves the work efficiency.

[0014] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic diagram of the structure of an embodiment of the present invention;

[0016] Figure 2 A schematic diagram of a measuring rod displacement measurement scheme according to an embodiment of the present invention; DETAILED DESCRIPTION

[0017] The present invention is further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0018] It should be understood that terms such as “having”, “including” and “comprising” used herein do not specify the existence or addition of one or more other elements or combinations thereof.

[0019] Figure 1An implementation form of the present invention is shown, which includes: a measuring platform 2 fixed on the side wall of a container 1, the measuring platform 2 is parallel to the upper surface of the measured liquid, a first through hole 3 and a second through hole 4 are provided on the measuring platform 2, a first measuring rod 5 and a second measuring rod 6 with the same length and cross-section respectively extend from top to bottom into the measured liquid through the first through hole 3 and the second through hole 4 and freely suspend in the measured liquid, a first displacement sensor 7 for detecting the up and down movement of the first measuring rod 5 is provided next to the first through hole 3, and a second displacement sensor 8 for detecting the up and down movement of the second measuring rod 6 is provided next to the second through hole 4; the weight of the first measuring rod 5 is 1.5 to 3 times the weight of the second measuring rod 6; the signals of the first displacement sensor 7 and the second displacement sensor 8 are connected to a PLC control module, and the PLC control module includes a data acquisition unit, a central processing unit, a storage unit, a power supply unit and a display input unit.

[0020] In this technical solution, the steps of using the device are as follows: Figure 1 As shown, the liquid to be measured is placed in a container 1, and the first measuring rod 5 and the second measuring rod 6 extend from top to bottom into the liquid to be measured through the first through hole 3 and the second through hole 4 respectively and are freely suspended in the liquid to be measured, the first displacement sensor 7 detects the upward displacement of the first measuring rod 5 in real time and transmits it to the data acquisition unit of the PLC control module, the second displacement sensor 8 detects the upward displacement of the second measuring rod 6 in real time and transmits it to the data acquisition unit of the PLC control module, the storage unit of the PLC control module stores the data collected by the data acquisition unit, and the central processing unit calculates the displacement of the first measuring rod 5 and the second measuring rod 6 and outputs the liquid specific gravity value to the display input unit for display.

[0021] The specific calculation formula is as follows:

[0022] According to Archimedes' principle: the buoyancy of an object immersed in a stationary liquid is equal to the weight of the liquid displaced by the object, and is in the vertically upward direction.

[0023] That is: F 浮 =G = ρ 液 ·g·V 排 , we can get: V 排 =G / (ρ 液 g)

[0024] The volume of liquid displaced by a cylinder or column in a liquid can also be calculated by multiplying the bottom area by the height of the column immersed in the liquid: V 排 =S·h

[0025] V 排 =S·h=G / (ρ 液 ·g) we can get: h = G / (ρ液 ·g·S)

[0026] The first measuring rod and the second measuring rod have the same length L and cross section S, but the weight G1 of the first measuring rod is 1.5 to 3 times the weight of the second measuring rod G2, so the heights h1 and h2 of the first measuring rod and the second measuring rod immersed in the liquid are also different.

[0027] It can be obtained that: h1-h2=(G1-G2) / (ρ 液 ·g·S)

[0028] Then: 液 =ΔG / (Δh·g·S), that is, the specific gravity of the liquid can be calculated through the weight difference between the first measuring rod and the second measuring rod, the height difference immersed in the liquid and the bottom area.

[0029] like Figure 2 As shown, since the lengths L of the first measuring rod and the second measuring rod are the same, the height difference between the two measuring rods immersed in the liquid can be obtained by measuring the difference in the upward displacement of the two measuring rods when suspended in the liquid.

[0030] Δh=h1-h2=(Lh 11 )-(Lh 21 )=h 21 -h 11

[0031] In another example, the first displacement sensor 7 is a first grating scale displacement sensor, the scale grating of the first grating scale displacement sensor 7 is vertically distributed on the first measuring rod 5, and the grating reading head of the first grating scale displacement sensor 7 is arranged beside the first through hole 3;

[0032] The second displacement sensor 8 is a second grating scale displacement sensor, the scale grating of the second grating scale displacement sensor 8 is vertically distributed on the second measuring rod 6, and the grating reading head of the second grating scale displacement sensor 8 is arranged beside the second through hole 4. Moreover, this method is only an explanation of a preferred example, but is not limited to this. When implementing the present invention, other displacement sensor implementations can be selected according to user needs.

[0033] One implementation of the first measuring rod 5 and the second measuring rod 6 in the above solution is that the first measuring rod 5 and the second measuring rod 6 are the same cylindrical or multi-prism-shaped body. This solution enables the measuring rod to be simply processed and reduces production costs.

[0034] One implementation of the first measuring rod 5 and the second measuring rod 6 in the above solution is that the first measuring rod 5 and the second measuring rod 6 are made of polytetrafluoroethylene or glass. This solution makes the measuring rod have strong chemical stability and is not easy to react with the measured liquid, thereby avoiding contamination of the measured liquid.

[0035] One implementation of the first measuring rod 5 and the second measuring rod 6 in the above solution is that the first measuring rod 5 and the second measuring rod 6 are hollow inside. With this solution, the first measuring rod 5 and the second measuring rod 6 can add a weight inside the hollow part, so as to adjust their own weight according to the measurement requirements of liquids with different specific gravities, further expanding the measurement range.

[0036] One implementation of the first measuring rod 5 and the second measuring rod 6 in the above solution is that a limiter 9 is provided at the top of the first measuring rod 5 and the second measuring rod 6. With this solution, the first measuring rod 5 and the second measuring rod 6 can be protected from touching the bottom of the container 1 in the case of low liquid level.

[0037] One implementation of the first measuring rod 5 and the second measuring rod 6 in the above solution is that the weight of the first measuring rod is twice the weight of the second measuring rod. This solution makes the processing of the measuring rods and the calculation of specific gravity easier.

[0038] One implementation of the display input unit in the above solution is that the display input unit is a handwriting display screen. This solution can simply and reliably realize the real-time display of the liquid specific gravity, and set the weight and bottom area of ​​the measuring rod through the handwriting display screen.

[0039] As described above, according to the present invention, since a displacement sensor is used to accurately measure the displacement of the first measuring rod and the second measuring rod, and data collection and calculation are performed through a PLC system, real-time and accurate measurement of the liquid specific gravity can be achieved, greatly improving work efficiency.

[0040] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and the embodiments. It can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily realized. Therefore, without departing from the general concept defined by the claims and equivalent scope, the present invention is not limited to the specific details and the illustrations shown and described here.

Claims

1. A liquid specific gravity measuring device, characterized in that: include: A measuring platform is fixed on the side wall of the container, the measuring platform is parallel to the upper surface of the measured liquid, a first through hole and a second through hole are arranged on the measuring platform, a first measuring rod and a second measuring rod with the same length and cross-section respectively extend from top to bottom into the measured liquid through the first through hole and the second through hole and freely suspend in the measured liquid, a first displacement sensor for detecting the up and down movement of the first measuring rod is arranged next to the first through hole, and a second displacement sensor for detecting the up and down movement of the second measuring rod is arranged next to the second through hole; the weight of the first measuring rod is 1.5 to 3 times the weight of the second measuring rod; the signals of the first displacement sensor and the second displacement sensor are connected to a PLC control module, and the PLC control module includes a data acquisition unit, a central processing unit, a storage unit, a power supply unit and a display input unit.

2. The liquid specific gravity measuring device according to claim 1, characterized in that: The first displacement sensor is a first grating ruler displacement sensor, the scale grating of the first grating ruler displacement sensor is vertically distributed on the first measuring rod, and the grating reading head of the first grating ruler displacement sensor is arranged beside the first through hole; The second displacement sensor is a second grating scale displacement sensor, the scale grating of the second grating scale displacement sensor is vertically distributed on the second measuring rod, and the grating reading head of the second grating scale displacement sensor is arranged beside the second through hole.

3. The liquid specific gravity measuring device according to claim 1, characterized in that: The first measuring rod and the second measuring rod are identical cylindrical or polygonal columns.

4. The liquid specific gravity measuring device according to claim 1, characterized in that: The first measuring rod and the second measuring rod are made of polytetrafluoroethylene or glass.

5. The liquid specific gravity measuring device according to claim 4, characterized in that: The first measuring rod and the second measuring rod are hollow inside.

6. The liquid specific gravity measuring device according to claim 1, characterized in that: Limiters are arranged at the top ends of the first measuring rod and the second measuring rod.

7. The liquid specific gravity measuring device according to claim 1, characterized in that: The weight of the first measuring rod is twice the weight of the second measuring rod.

8. The liquid specific gravity measuring device according to claim 1, characterized in that: The display input unit is a handwriting display screen.

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