KR100462386B1 - Coefficient Of Heat Expansion Of Non-magnetic Substance Measuring Device In Accordance With The Magnetic Field Change - Google Patents

Abstract

The present invention uses the correlation between the magnetic field of the coil that changes while being physically expanded and wound around the thermally expandable nonmagnetic material and the temperature of the nonmagnetic material that exchanges heat with the outside. A device for measuring a coefficient of thermal expansion of a nonmagnetic material, the coil being wound on the outer surface of the nonmagnetic material thermally expanded so as to have a correlation with a predetermined number of times to be physically expanded, and both ends of the coil to form a magnetic field in the coil. A power supply unit for applying currents of different polarities to each other, an electromagnetic thermometer which is installed in contact with or close to the surface of the nonmagnetic material and detects a temperature change, and installed at a corresponding position of the nonmagnetic material corresponding to the center of the coil A magnetic field measuring device for detecting a change in the magnetic field according to the expansion of the coil, And a controller connected to the electromagnetic thermometer and the magnetic field meter to compare and check the expansion amount of the coil based on the magnetic field, and convert the sensed temperature and the magnetic field into a digital signal and send the digital signal to the controller. It is characterized by including a digital voltmeter electrically connected between the.

Description

Coefficient Of Heat Expansion Of Non-magnetic Substance Measuring Device In Accordance With The Magnetic Field Change}

The present invention relates to a device for measuring the coefficient of thermal expansion of a nonmagnetic material as a structure having a correlation between a magnetic field generated when a current is applied to a coil wound around the nonmagnetic material and a temperature of the nonmagnetic material that exchanges heat with the outside. In more detail, the coil is wound tightly to expand according to the thermal expansion of the nonmagnetic material, and a magnetic field meter is installed to measure the magnetic field that changes as it expands inside the nonmagnetic material corresponding to the center of the coil. The present invention relates to a device for measuring the coefficient of thermal expansion of a nonmagnetic material according to a change in a magnetic field, which is a structure in which a thermistor is installed to detect a temperature change in the temperature of the nonmagnetic material.

In general, when the temperature applied to the molten body is changed, the coefficient of thermal expansion for the temperature change is measured by measuring the change in the molter size. Therefore, the measurement of the temperature change of a nonmagnetic material is consequently a measure of the coefficient of thermal expansion of the nonmagnetic material. At this time, if the size or shape of the nonmagnetic material is not suitable for the temperature measurement, a portion of the nonmagnetic material is conventionally cut into a size and shape suitable for measuring the temperature change, and then the temperature change is measured on the cut sample. have.

In this case, the factors derived from the intact shape and size of the nonmagnetic material are excluded, so that a more accurate measurement of the coefficient of thermal expansion is difficult. If a large non-magnetic material, for example, the trunk of a tree, the conventional method mentioned above is to measure by cutting a part of the trunk. In this case, there is a problem that a significant error appears between the coefficient of thermal expansion and the actual coefficient of thermal expansion of the entire trunk as the inner and outer structures and densities of the trunk are different from the surface to the center.

As described above, it is very difficult to obtain the thermal expansion coefficient of a nonmagnetic material relatively accurately. This process assumes that the internal and external structures and densities of all nonmagnetic materials are uniform, and the part of the conventional idealization process that measures and extends a part of the nonmagnetic material is analyzed. And the measurement principle based thereon.

Therefore, there is a demand for the development of a method or apparatus capable of measuring the coefficient of thermal expansion under the condition of preserving the intact form of the nonmagnetic material without any limitation on the shape or size.

Accordingly, the present invention has been made in view of the above-described conventional problems, and a first object of the present invention is to maintain a nonmagnetic material in an intact form, and to measure the thermal expansion coefficient of the nonmagnetic material. It is to provide a thermal expansion coefficient measuring apparatus of.

A second object of the present invention is to provide an apparatus for measuring the coefficient of thermal expansion of a nonmagnetic material in accordance with a change in the magnetic field of a structure capable of measuring the coefficient of thermal expansion of the nonmagnetic material based on a correlation between temperature and a magnetic field.

The object of the present invention as described above, the coil 100 is wound on the outer surface of the non-magnetic material (2000) that is thermally expanded so that the temperature and magnetic field have a predetermined number of times to physically expand;

A power supply unit 200 for applying current having different polarities to both ends of the coil 100 so that a magnetic field is formed in the coil 100;

An electronic thermometer 400 installed in contact with or in proximity to the surface of the nonmagnetic material 2000 to detect a temperature change;

A magnetic field meter (500) installed at a corresponding position of the nonmagnetic material (2000) corresponding to the center of the coil (100) to detect a magnetic field change due to the expansion of the coil (100);

A controller 700 connected to the electromagnetic thermometer 400 and the magnetic field meter 500 such that the expansion amount of the coil 100 is compared and checked based on the detected temperature and the magnetic field; And

A digital voltmeter 600 electrically connected between the electronic thermometer 400 and the magnetic field meter 500 and the controller 700 so as to convert the detected temperature and magnetic field into a digital signal and send it to the controller 700. It is achieved by a device for measuring the coefficient of thermal expansion of the nonmagnetic material according to the magnetic field change, characterized in that comprising a.

Herein, the electron thermometer 400 is preferably a thermistor indicating a temperature change by an electrical resistance number.

In addition, the coil 100 may be any one selected from a coil structure capable of calculating a magnetic field including a Helmholtz coil and a solenoid coil wound such that a distance between adjacent spirals is equal to a radius.

In addition, the coil 100 preferably further includes a resistance circuit unit 300 connected to the controller 700 through the digital voltmeter 600 to detect the amount of applied current.

In addition, the magnetic field measuring device 500 may include a phase comparison structure, and may be an atomic magnetic resonance magnetic field measuring structure using optical pumping to observe the amount of change in the small magnetic field.

Other objects, specific advantages and novel features of the present invention will become more apparent from the following detailed description and the preferred embodiments associated with the accompanying drawings.

1 is a block diagram of a thermal expansion coefficient measuring apparatus according to a first embodiment of the present invention,

2 is a flowchart of a measuring method using the measuring apparatus of the present invention;

3 is a block diagram of a thermal expansion coefficient measuring apparatus according to a second embodiment of the present invention.

<Description of the code | symbol about the principal part of drawing>

100: coil 200: power supply

300: resistance circuit 400: electronic thermometer

500: magnetic field meter 510: support member

600: digital volt meter 700: controller

1000: measuring device 2000: nonmagnetic material

Next, the thermal expansion coefficient measuring apparatus of the nonmagnetic material according to the magnetic field change according to the present invention will be described with reference to the accompanying drawings.

1 is a block diagram of a thermal expansion coefficient measuring apparatus according to a first embodiment of the present invention, Figure 2 is a flow chart of a measuring method using the measuring apparatus of the present invention. 1 and 2, the measuring device 1000 is a structure in which a coil 100 applied with a current is applied to a surface of a nonmagnetic material 2000 such that temperature and a magnetic field have a correlation with each other. When the thermal expansion (2000) as the temperature rises, the diameter of the coil 100 is expanded, thereby causing a change in the magnetic field.

In this case, the Helmholtz coil is a formula that detects the change in the magnetic field according to the unit temperature with the electronic thermometer (400) and the magnetic field measuring instrument (500), and calculates the magnetic field by the winding number, diameter, and diameter change of the coil 100 functioning as variables. In the magnetic field calculation formula, it is possible to obtain the degree of expansion of the nonmagnetic material 2000 and measure the coefficient of thermal expansion by deriving and calculating the change in diameter based on the number of windings and the magnetic field which are already known.

The measuring device 1000 includes a power supply unit 200 for applying a current having a different polarity to both ends of the coil 100 and the coil 100 wound around the nonmagnetic material 2000, and the nonmagnetic material 2000. Or an electromagnetic thermometer 400 for detecting the amount of change in the temperature around the magnetic field meter and a magnetic field meter 500 for detecting the amount of change in the magnetic field of the coil 100.

Here, the coil 100 is wound on the nonmagnetic material 2000 in a predetermined number of times so as to be in close contact with the surface, and the coil 100 wound at this time is a Helmholtz coil and a solenoid coil to detect an expansion amount of the coil 100 more accurately. It is preferable to have a form which can be computed.

If the nonmagnetic material 2000 is heated and thermally expanded, the wound coil 100 also expands as the nonmagnetic material 2000 expands. In this expansion, the magnetic field is changed by the expansion of the radius of the coil 100. For example, the correlation between the radius of the coil 100 and the magnetic field can be known by the Helmholtz magnetic field calculation formula described below.

In Equation 1, H is a magnetic field at the center of the coil 100 of the Helmholtz type, N is the number of windings of the coil 100, and I is a current flowing through the coil 100. R is the radius of the coil 100. If we derive the formula for the change of magnetic field, △ H,

In Equation 2 induced by the change amount of the magnetic field as ΔH, Δr is the amount of change in the radius of the coil 100 that changes according to the passion expansion of the nonmagnetic material 2000. Since the radius r of the coil 100 before expansion, the winding number N, the current amount I, and the change amount ΔH of the magnetic field are already known, the change amount may be calculated when the equation 2 is induced and aligned with respect to Δr.

At this time, the winding number is known when the coil 100 is wound on the nonmagnetic material 2000, and the radius of the coil 100 can be known by measuring. By the way, both ends of each of the coils 100 are electrically connected to the power supply unit 200 for applying a current of different polarity, the resistance circuit unit 300 is connected on the series circuit in which the power supply unit 200 is formed have.

At this time, the resistance circuit unit 300 is connected to a digital volt meter (600) functioning as an A / D converter can measure the amount of current applied from the power supply.

In addition, the electronic thermometer 400 is installed at a position close to or in contact with the surface of the nonmagnetic material 2000. The electronic thermometer 400 is a thermistor including a ceramic resistor made of manganese, nickel, and cobalt, and can be accurately detected even if the temperature change is insignificant because the response is very fast. In the thermistor, a low electric resistance water is emitted as the temperature rises, and the digital voltmeter 600 is connected thereto. In one embodiment of the present invention, the electronic thermometer 400 is disposed close to the surface of the nonmagnetic material 2000.

In this case or as in the case of contact installation, the main point is to obtain the temperature change amount for a predetermined time regardless of the surface of the nonmagnetic material 2000 or its surroundings rather than the temperature sensing at the corresponding time. This is because the nonmagnetic material 2000 is not insulated but continuously heat exchanged with the outside (for example, ambient air, etc.), so that the increased temperature due to the absorbed heat and the reduced temperature due to the emission are the same in absolute value. .

In addition, a magnetic field meter 500 is installed at the center of the nonmagnetic material 2000. This installation position of the magnetic field meter 500 is the center of the coil 100 having the largest amount of magnetic field generated when a current is applied to the coil 100.

In this case, the magnetic field measuring device 500 preferably includes a phase comparison structure and an atomic magnetic resonance magnetic field measuring structure using optical pumping. The magnetic field measuring device 500 of such a structure can measure even a very small magnetic field change. In FIG. 1, a solid nonmagnetic material 2000 is illustrated as an embodiment. In this case, the magnetic field meter 500 is installed in the nonmagnetic material 2000 corresponding to the center of the coil 100. do.

In addition, the current amount of the power supply unit 200 applied to the coil 100 may be obtained through the resistance circuit unit 300 having a predetermined number of resistances connected to the coil 100 and the power supply unit 200.

Accordingly, it is possible to measure the change in magnetic field and the amount of applied current according to the temperature change and radius expansion. Through this, it is possible to calculate the amount of change in the magnetic field at a predetermined value according to the unit temperature (for example, 1 ° C.).

Since the change amount of the magnetic field, that is, ΔH of Equation 2 described above, can be obtained, when Δr is substituted into each of the variables (ΔH, N, I, etc.) thus obtained, Equation 2 is calculated, It is possible. Therefore, the coefficient of thermal expansion of the nonmagnetic material 2000 may be calculated and finally obtained through Δr / r, which is a radius expansion degree of the coil 100 per unit temperature.

In addition, the digital voltmeter 600 is connected to the port of the controller 700 of the computer type. Accordingly, the analog signal transmitted from the electronic thermometer 400 and the magnetic field measuring instrument 500 and the resistance circuit unit 300 connected to the coil 100 and the power supply unit 200 is converted into a digital signal to the controller 700. By sending, the controller 700 can check this in real time.

Each variable value checked as described above is inputted to a calculation program related to Equation 2 stored in the controller 700 and processed. The calculated result can be displayed on a monitor or printed in writing to an output device (for example, a printer).

A process of measuring the coefficient of thermal expansion of the nonmagnetic material 2000 through the measuring device 1000 having such a structure will be described.

First, the coil 100 is wound on the outer surface of the nonmagnetic material 2000 to be measured while being wound up a predetermined number of times.

In addition, current is applied to both ends of the coil 100 through the power supply unit 200 to form a magnetic field.

At this time, through the digital voltmeter 600 connected to the resistance circuit unit 300, the applied current amount is converted into a digital signal by A / D conversion and sent to the controller 700. (S3000)

In addition, the magnetic field measuring unit 500 and the electronic thermometer 400 detects the magnetic field change and temperature change for a predetermined time, converts them into digital signals, and sends them to the controller 700. (S4000)

In addition, by inputting each detection variable in the equation (2) for the Helmholtz magnetic field formula loaded on the controller 700, the thermal expansion coefficient of the corresponding nonmagnetic material 2000 is measured and obtained.

3 is a block diagram of a thermal expansion coefficient measuring apparatus according to a second embodiment of the present invention. As shown in FIG. 3, in the measuring apparatus 1000, a nonmagnetic material 2000 having a hollow bobbin shape is provided as a measurement object. In this case, the magnetic field meter 500 is inserted into the center of the nonmagnetic material 2000 corresponding to the center of the coil 100 and fixedly installed by the plurality of support members 510.

In addition, the electronic thermometer 400 is installed close to the surface of the nonmagnetic material 2000 as an example. Alternatively, the electronic thermometer 400 may be installed in contact with the surface of the nonmagnetic material 2000 or may be installed inside the hollow nonmagnetic material 2000. It's okay.

The power supply unit 200 is connected to the coil 100 to apply current, and the resistance circuit unit 300 is connected to the power supply unit 200 and the coil 100.

In addition, the resistance circuit unit 300, the electronic thermometer (400) and the magnetic field meter 500 is connected to the digital voltmeter 600 is converted to a digital signal detected in the analog form and sent to the controller 700.

By measuring the winding number of the coil 100 and the spiral radius before expansion through the measuring device 1000 of such a structure, the temperature change and the magnetic field for a predetermined time through the electronic thermometer 400 and the magnetic field meter 500 Measure the change. In addition, by obtaining the amount of current applied from the power supply unit 200 based on the predetermined number of resistors of the resistance circuit unit 300 and substituting the above-mentioned equation (2), the radius extension of the coil 100 is calculated to eventually obtain the corresponding visa. The thermal expansion coefficient of the adult body 2000 can be measured.

In the apparatus 1000 for measuring the coefficient of thermal expansion of a nonmagnetic material according to a magnetic field change according to the present invention as described above, the nonmagnetic material 2000 has a symmetrical structure as well as an asymmetrical structure and a partly formed space therein. Measurements can be made without limitation of size or shape, and the coil 100 may be wound on the outer surface.

In addition, the shape of the coil 100 is not limited to the aforementioned Helmholtz coil structure, and may be a structure capable of calculating a magnetic field such as a solenoid coil.

In addition to the atomic magnetic resonance magnetic field measuring structure using optical pumping, the magnetic field measuring instrument 500 can also use a flux gate magnetic field measuring structure, and it is possible to measure precisely in consideration of the small amount of change in the magnetic field and to respond. It is possible to select and use among the fast measuring structures.

According to the apparatus for measuring the coefficient of thermal expansion of a nonmagnetic material according to the magnetic field change as described above, the coefficient of thermal expansion can be measured while maintaining the intact shape and size of the nonmagnetic material. Compared with the thermal expansion coefficient of, the precision is greatly improved, and it is characterized by being independent of the constraints of the shape and size of the nonmagnetic material.

In addition, the structure and the measurement process is relatively simple, there is an advantage that can be measured in the original position of the nonmagnetic material.

Although the present invention has been described in connection with the above-mentioned preferred embodiments, it is possible to make various modifications or variations without departing from the spirit and scope of the invention. Accordingly, the appended claims will cover such modifications and variations as fall within the spirit of the invention.

Claims (5)

A coil 100 that is wound on the outer surface of the nonmagnetic material 2000 that is thermally expanded to have a correlation between temperature and a magnetic field and is physically expanded; A power supply unit 200 for applying current having different polarities to both ends of the coil 100 so that a magnetic field is formed in the coil 100; An electronic thermometer 400 installed in contact with or in proximity to the surface of the nonmagnetic material 2000 to detect a temperature change; A magnetic field meter (500) installed at a corresponding position of the nonmagnetic material (2000) corresponding to the center of the coil (100) to detect a magnetic field change due to expansion of the coil (100); A controller (700) connected to the electromagnetic thermometer (400) and the magnetic field meter (500) so as to compare and process the amount of expansion of the coil (100) based on the detected temperature and the magnetic field; And A digital voltmeter electrically connected between the electronic thermometer 400 and the magnetic field meter 500 and the controller 700 so as to convert the detected temperature and magnetic field into a digital signal and send it to the controller 700. 600); The thermal expansion coefficient measuring apparatus of the nonmagnetic material according to the magnetic field change, characterized in that comprising a. The method of claim 1, The electronic thermometer 400 is a device for measuring the coefficient of thermal expansion of a nonmagnetic material according to a magnetic field change, characterized in that the thermistor indicating the temperature change in the electrical resistance number. The method of claim 1, The coil 100 is any one selected from a coil structure capable of calculating a magnetic field composed of a Helmholtz coil and a solenoid coil wound such that a distance between adjacent spirals is equal to a radius. Apparatus for measuring the coefficient of thermal expansion of adults. The method of claim 1, The coil 100 further includes a resistance circuit unit 300 connected to the controller 700 through the digital voltmeter 600 to detect the amount of applied current. Thermal expansion of the nonmagnetic material according to the magnetic field change is further provided. Coefficient measuring device. The method of claim 1, The magnetic field measuring device 500 is a device for measuring the coefficient of thermal expansion of the nonmagnetic material according to the magnetic field changes, characterized in that the atomic resonance magnetic field measuring structure using optical pumping including a phase measuring structure.