Liquid surface tension coefficient measuring device

Abstract

The utility model discloses a liquid surface tension coefficient measuring device, and mainly relates to the technical field of optical fiber sensing. Comprising an optical fiber force sensor, a signal light source, a spectrum analyzer, a hanging ring, a liquid level adjusting device, a weight disc and an iron support, the optical fiber force sensor comprises an optical fiber sensing structure and an optical fiber clamp, and the optical fiber sensing structure is an SMS structure formed by a coreless optical fiber and a first single-mode optical fiber and a second single-mode optical fiber which are connected with the two ends of the coreless optical fiber in a bent state; the first single-mode optical fiber and the second single-mode optical fiber extend to the optical fiber clamp and are fixed by the optical fiber clamp, the first single-mode optical fiber is connected with the output end of a signal light source, and the second single-mode optical fiber is connected with the input end of a spectrum analyzer. The beneficial effects of the utility model are that the device can improve the measurement precision, and also has the advantages of high measurement efficiency, low consumption, and simple operation.

Description

Technical Field

[0001] This utility model relates to the field of fiber optic sensing technology, specifically a liquid surface tension coefficient measuring device based on the bending and strain characteristics of SMS fiber structures. Background Technology

[0002] The surface tension of a liquid is an important parameter characterizing its properties. Accurate and rapid measurement of the liquid surface tension coefficient (LSTC) is an important and necessary step in applications such as food, pharmaceuticals, cosmetics, and coating technology.

[0003] Currently, the pull-out method, which is commonly used in teaching demonstrations, is a method for studying the surface properties of liquids by measuring the surface tension coefficient. This method can intuitively demonstrate the existence and role of liquid surface tension, and is very helpful for understanding and explaining some phenomena related to liquid surface tension, such as foam formation and wetting. However, when using the pull-out method to measure the surface tension coefficient of liquids with photoelectric sensors, the photoelectric sensors are often affected by the external environment and have a low signal transmission / response speed, which can easily lead to large experimental errors.

[0004] Therefore, there is an urgent need for a liquid surface tension coefficient measuring device based on the bending and strain characteristics of SMS fiber structures to solve the problem of large measurement errors of liquid surface tension coefficient in actual teaching demonstrations. Utility Model Content

[0005] The purpose of this invention is to provide a liquid surface tension coefficient measuring device that can improve measurement accuracy while also having the advantages of high measurement efficiency, low consumption, and simple operation.

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

[0007] The main structure includes an optical fiber force sensor, a signal light source, a spectrometer, a lifting ring, a liquid level adjustment device, a weight pan, and an iron stand. The optical fiber force sensor includes an optical fiber sensing structure and an optical fiber clamp. The optical fiber sensing structure is an SMS structure in a bent state consisting of a coreless optical fiber and a first single-mode optical fiber and a second single-mode optical fiber connected to its two ends. The first single-mode optical fiber and the second single-mode optical fiber extend to the optical fiber clamp and are fixed thereto. The first single-mode optical fiber is connected to the output end of the signal light source, and the second single-mode optical fiber is connected to the input end of the spectrometer.

[0008] Preferably, the lifting ring is provided with a hook, the lifting ring is disposed on a coreless optical fiber, and is connected to an optical fiber force sensor.

[0009] Preferably, the liquid level adjusting device comprises a liquid level regulator, a water tank and a culture dish, the liquid level regulator is arranged on the iron stand, the water tank is arranged on the weight disc of the liquid level regulator, and the culture dish is arranged in the water tank and connected with the optical fiber force sensor through a hanging ring.

[0010] Preferably, the bend radius of the coreless optical fiber is greater than 1 cm.

[0011] Compared with the prior art, the liquid surface tension measuring demonstration instrument has the advantages that:

[0012] The refractive index (RI) in the MMF is changed by external force, thereby modulating the wavelength of the transmitted light, and the resonant wavelength generated by the multi-mode interference can conveniently indicate the spectral drift caused by the external force. The signal light source transmits light to the coreless multi-mode optical fiber through the first single-mode optical fiber. When the light is transmitted from the single-mode optical fiber to the step multi-mode optical fiber, a large number of high-order modes are excited, and the modes interfere at the output point. Due to the effect of stress, the refractive index of the coreless multi-mode optical fiber changes, resulting in a wavelength shift of the interference inclination angle. The light is transmitted from the coreless multi-mode optical fiber to the second single-mode optical fiber and finally enters the optical spectrum analyzer. The optical spectrum analyzer analyzes the spectral information, records the output spectral drift at the separation moment, and obtains the LSTC of the measured liquid. The external force applied on the curved SMS fiber structure is directly related to the surface tension of the liquid, and the surface tension is not enough to change the bending radius R of the balloon-shaped fiber. As a result, the transmission spectrum of the SMS structure drifts, and the external force can be deduced from the analyzed transmission spectrum, so that the surface tension of the liquid can be accurately determined. The optical fiber material is used as the sensing element in the application. The optical fiber has the advantages of fast transmission, small transmission loss, etc. The application has the advantages of high sensitivity, high measurement accuracy, rapid measurement, good repeatability and stability, high efficiency, low consumption and simple operation. BRIEF DESCRIPTION OF DRAWINGS

[0013] Fig. 1 is the schematic diagram of the overall structure of the liquid surface tension measuring demonstration instrument based on the bending and strain characteristics of the SMS fiber structure provided by the utility model;

[0014] Fig. 2 is the schematic diagram of the optical fiber force sensor provided by the utility model.

[0015] Reference signs shown in the drawings:

[0016] 1, optical fiber clamp, 2, coreless multi-mode optical fiber, 3, first single-mode optical fiber, 4, second single-mode optical fiber, 5, signal light source, 6, optical spectrum analyzer, 7, iron stand, 8, water tank, 9, culture dish, 10, hanging ring, 11, liquid level regulator, 12, iron support, 13, weight disc. DETAILED DESCRIPTION

[0017] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the present invention, and these equivalent forms also fall within the scope defined in this application.

[0018] In this invention, terms such as "upper," "lower," "left," "right," "front," "back," "vertical," "horizontal," "side," and "bottom" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are used only to facilitate the description of the structural relationships of the various components or elements of this invention and do not specifically refer to any component or element in this invention. They should not be construed as limiting the invention.

[0019] In this invention, terms such as "fixed connection," "connected," and "linked" should be interpreted broadly, indicating a fixed connection, an integral connection, or a detachable connection; a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can determine the specific meaning of these terms in this invention based on the specific circumstances, and they should not be construed as limitations on the invention.

[0020] Example:

[0021] like Figs. 1-2 As shown, this embodiment provides a liquid surface tension measurement demonstration instrument based on the bending and strain characteristics of SMS fiber structures, including: an optical fiber force sensor, a signal light source, a spectrometer, a hanging ring, a liquid level adjustment device, a weight pan, an iron stand, a water tank, and a petri dish. The optical fiber force sensor includes an optical fiber sensing structure and an optical fiber clamp.

[0022] The fiber optic force sensor includes a fiber optic sensing structure and a fiber optic clamp. The fiber optic sensing structure is an SMS structure consisting of a coreless optical fiber and a first single-mode fiber and a second single-mode fiber connected to its two ends in a bent state. The first single-mode fiber and the second single-mode fiber extend to and are fixed by the fiber optic clamp. The fiber optic force sensor is provided assembled for easy connection to other devices and use in teaching activities.

[0023] The first single-mode fiber is connected to the output end of the signal light source, and the second single-mode fiber is connected to the input end of the spectrometer.

[0024] The ring is suspended from the bend point of the coreless multimode optical fiber via its own hook and connected to the optical fiber force sensor. The metal ring is immersed in the liquid to be tested.

[0025] The liquid level lifting device comprises a liquid level regulator, a water tank and a culture dish. The liquid level regulator is placed on the iron stand, the water tank filled with water is placed on the weight disc of the liquid level regulator, the culture dish filled with the liquid to be measured is placed on the water surface in the water tank, and the hanging ring is connected with the optical fiber force sensor.

[0026] In the implementation process, the bending radius R of the SMS coreless optical fiber is greater than 1cm, so as to avoid excessive loss caused by too small curvature.

[0027] In the implementation process, the bending diameter of the SMS fiber structure is 1.35cm, and the coreless optical fiber is used to realize high sensitivity force sensing.

[0028] The working process of the liquid surface tension measurement demonstration instrument based on the bending and strain characteristics of the SMS fiber structure is as follows:

[0029] The signal light source provides light, which is conducted through the first single-mode optical fiber and transmitted into the coreless multimode optical fiber. When the light is transmitted from the single-mode optical fiber to the step multimode optical fiber, a large number of high-order modes will be excited, and these modes will interfere at the output point. The height is adjusted by the liquid level regulator, so that the hanging ring gradually separates from the liquid to be measured, the force at the circular ring gradually changes, the change of the force is transmitted to the coreless multimode optical fiber through the self-hanging hook, and the refractive index of the coreless multimode optical fiber changes due to the stress, which causes the wavelength of the interference inclination angle to shift. The changed light is transmitted to the optical spectrum analyzer through the second single-mode optical fiber, and the optical spectrum analyzer analyzes the spectrum information. When the circular ring gradually separates from the surface of the liquid to be measured, the change of the surface tension will be recorded in the form of spectrum on the optical spectrum analyzer. When the circular ring leaves the surface of the liquid to be measured, the surface tension of the liquid changes greatly, the transmission spectrum of the SMS structure drifts, and the LSTC of the measured liquid is obtained.

Claims

1. A liquid surface tension coefficient measuring device, characterized by, The application relates to a fiber-optic force sensor, a signal light source, a spectrum analyzer, a hanging ring, a liquid level adjusting device, a weight disc and an iron stand, wherein the fiber-optic force sensor comprises a fiber-optic sensing structure and a fiber-optic clamp; the fiber-optic sensing structure is an SMS structure of a hollow fiber and first and second single-mode optical fibers connected to two ends of the hollow fiber in a bending mode; the first and second single-mode optical fibers extend to the fiber-optic clamp and are fixed by the fiber-optic clamp; the first single-mode optical fiber is connected to an output end of the signal light source; and the second single-mode optical fiber is connected to an input end of the spectrum analyzer.

2. The liquid surface tension coefficient measuring device according to claim 1, wherein A hook is arranged on the hanging ring, the hanging ring is arranged on the hollow fiber and is connected to the fiber-optic force sensor.

3. The device for measuring the coefficient of surface tension of a liquid according to claim 1, wherein The liquid level adjusting device comprises a liquid level regulator, a water tank and a culture dish; the liquid level regulator is arranged on the iron stand; the water tank is arranged on the weight disc which is also a regulator; the culture dish is arranged in the water tank and is connected to the fiber-optic force sensor through the hanging ring.

4. The device for measuring the coefficient of surface tension of a liquid according to claim 1, wherein The bending radius of the hollow fiber is greater than 1 cm.

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