KR20230021918A - Ultrasonic temperature sensing apparatus of using magnetostrictive principle and sensing method thereof - Google Patents

Abstract

Provided is an ultrasonic temperature measuring apparatus using a magnetostrictive principle. The ultrasonic temperature measuring apparatus comprises: a magnetostrictive wire used as an ultrasonic waveguide; a reflection point unit fixed and disposed at one position in the longitudinal direction of the wire; a pulse transmitting unit disposed at one end of the wire to apply a pulse current to the wire, providing the periphery of the wire with a second magnetic field in a circumferential direction with respect to the wire; a wire fixing unit disposed on the other side of the wire to fix the wire; and a receiving unit for measuring the temperature of the reflection point unit through a first sensing coil unit that detects a change due to a third magnetic field if the second magnetic field moves along the wire so that the third magnetic field is formed in the point at which the second magnetic field meets the reflection point unit. Therefore, the ultrasonic temperature measuring apparatus can measure the temperature of an object to be measured by using the wire, which is a solid, as an ultrasonic waveguide.

Description

Ultrasonic temperature measuring device using magnetostriction principle and measuring method thereof

The present invention relates to a temperature measuring device using the magnetostriction principle and a method for measuring the same, and more particularly, to a device and method capable of measuring the temperature of an object to be measured by detecting a torsion wave of a magnetostrictive wire.

Temperature is one of the physical properties, and is measured by first measuring other physical quantities such as displacement, pressure, resistance, and frequency, and then converting them. Currently, the most widely used throughout the industry is a thermocouple that measures temperature through a change in resistance value. Since the thermocouple is directly attached and installed at the point where the temperature is to be measured, it has advantages of simple and easy installation, low thermal inertia, and small measurement error.

However, if used for a long time under the same temperature conditions, a draft error may occur in which the measured resistance value gradually decreases even though there is no temperature change. (Calibration) work or replacement is required. In addition, since the thermocouple measures the temperature at a single point attached to the point to be measured, if heat distribution is checked or temperature measurement at various points is required, the number of measurements must be installed.

Recently, due to the technical need for multi-level or multi-point measurement, research on ultrasonic temperature measurement using an ultrasonic waveguide has been conducted. However, most of the existing temperature measurement technologies using ultrasonic waves have various problems such as surface management of the transmitter and receiver, influence of obstacles between the measurement target and the transmitter and receiver, and diffuse reflection due to the surrounding environment.

Korean Registered Patent Publication No. 10-1954567 Surface temperature measuring device using ultrasonic waveguide Japanese Patent Registration No. 4453023 Fluid Pressure Cylinder with Position Detection Device Korean Registered Patent Publication No. 10-0635397 Thickness measurement method by ultrasound performing real-time temperature correction

Embodiments of the present invention have been made to solve the above problems, and an ultrasonic temperature measuring device using a magnetostriction principle capable of measuring the temperature of an object to be measured using a solid wire as an ultrasonic waveguide, and We want to provide that method.

In addition, it is intended to provide a temperature measuring device and measuring method capable of solving the structural limitations (curve, curved surface, etc.) of the space where the temperature measurement is performed and the measurement limitation according to the surrounding environment.

In addition, it is intended to provide a temperature measurement algorithm applicable to a temperature measurement device. Through this, it is intended to further secure the reliability of the temperature measuring device and its measuring method. In addition, by facilitating the coupling relationship between each component of the device, maintenance and management are convenient.

In addition, it is intended to measure magnetic field change and torsional displacement of a wire due to torsion waves generated by a spiral magnetic field. Through this, it is intended to further expand not only the temperature but also the physical quantity measured simultaneously. It is intended to reduce the measurement deadband area existing in the existing ultrasonic measuring device.

Embodiments of the present invention to solve the above problems, the magnetostrictive wire used as an ultrasonic waveguide; a reflection point portion fixedly disposed at any one position in the length direction of the wire; a pulse transmitter disposed at one end of the wire and applying a pulse current to the wire to provide a second magnetic field around the wire in a circumferential direction with respect to the wire; a wire fixing unit disposed on the other side of the wire and fixing the wire; And when the second magnetic field moves along the wire and a third magnetic field is formed at a point where it meets the reflection point, the temperature of the reflection point is measured through a first sensing coil that detects a change by the third magnetic field. It provides an ultrasonic temperature measuring device using a magnetostriction principle including a receiving unit for measuring.

Preferably, the reflection point portion is a magnetic material providing a first magnetic field in an axial direction with respect to the wire around the wire.

When a plurality of reflection point parts are formed, it is preferable that the average of the temperature values of the reflection point part is the temperature of the object to be measured.

The receiving unit further includes a signal processing unit analyzing a reflected signal through the first sensing coil unit, wherein the signal processing unit detects a change in the second magnetic field and a change in the third magnetic field. It is preferable to embed a temperature measurement algorithm for measuring the temperature of the reflection point portion using the d-th time difference, which is the time difference between the c-th times at which is detected.

The signal processing unit calculates in advance a d1th time difference, which is a time difference between a b1th time when a change by the second magnetic field is detected and a c1th time when a change by the third magnetic field is detected in a certain day reference temperature, After calculating the d2th time difference, which is the time difference between the b2th time at which the change by the second magnetic field is detected and the c2th time at which the change by the third magnetic field is detected through the object of temperature measurement, in real time, the d2th time difference is calculated. Preferably, the temperature of the reflection point portion is measured by finally calculating the d3-th time difference, which is the time difference between the time difference and the d1-th time difference.

Preferably, the temperature measuring algorithm is different according to a temperature rising section in which the temperature of the reflection point portion rises and a temperature falling section in which the temperature of the reflection point portion decreases.

The receiving unit further includes a second sensing coil unit configured to measure a torsional displacement of the wire by detecting a change by the third magnetic field, and the measurement dead band area is mutually dependent on the arrangement position of the first sensing coil unit. It is formed at a different position, and the second sensing coil is preferably disposed within the measurement dead zone.

A temperature measurement method using a temperature measurement algorithm embedded in a receiving unit among ultrasonic temperature measurement devices using a magnetostriction principle, comprising: a first step of collecting a reflected signal through the first sensing coil unit; A second step of calculating the propagation time of the ultrasonic wave at a predetermined reference temperature, calculating the propagation time of the ultrasonic wave for the object to be measured, and then calculating the difference in the propagation time of the ultrasonic wave according to the temperature change; A third step of calculating a function having, as an input value, a difference in propagation time of ultrasonic waves according to the temperature change in a temperature rising section and a temperature falling section, respectively; and a fourth step of calculating the real-time temperature of the object to be measured using the function.

According to the problem solving means of the present invention as described above, various effects including the following can be expected. However, the present invention is not established when all of the following effects are exhibited.

An ultrasonic temperature measurement device using a magnetostriction principle according to an embodiment of the present invention may measure the temperature of an object to be measured by using a solid wire as an ultrasonic waveguide. In addition, it is possible to solve the structural limitations (curve, curved surface, etc.) of the space where the temperature measurement is made and the measurement limitation according to the surrounding environment. In addition, by providing a temperature measurement algorithm applicable to a temperature measurement device, reliability of the temperature measurement method can be further secured.

In addition, it is possible to measure the magnetic field change and the torsion displacement of the wire due to the torsional wave generated by the spiral magnetic field. Through this, it is possible to further expand not only the temperature but also the physical quantity measured at the same time. In addition, it is possible to reduce a measurement deadband area existing in an existing ultrasonic measuring device.

1 is a schematic configuration diagram of an ultrasonic temperature measuring device according to an embodiment.
Figure 2 is a view showing the temperature measurement principle of Figure 1;
3 is a diagram showing a graph of an initial signal and a reflected signal detected from a first sensing coil unit when a pulse current is applied;
Figure 4 is a schematic diagram of the first to fourth coils.
5 is a diagram showing an oscilloscope graph of a pulse current (excitation pulse) applied and a reflected signal (detection signal) reflected from a reflection point portion in a temperature rise section of a magnetostrictive wire.
6 is a diagram showing an oscilloscope graph of a pulse current (excitation pulse) applied and a reflected signal (detection signal) reflected from a reflection point portion in a temperature decreasing period of a magnetostrictive wire.
7 is a graph showing a trend line for a tertiary exponential function in the temperature rise section of FIG. 1;
8 is a graph showing a trend line for a tertiary polynomial function in the temperature decreasing section of FIG. 1;
9 is a schematic flowchart of an ultrasonic temperature measurement method according to an embodiment.

In order to fully understand the configuration and effects of the present disclosure, preferred embodiments of the present disclosure will be described with reference to the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below, and may be implemented in various forms and various changes may be made. Hereinafter, in the description of the present invention, detailed descriptions thereof will be omitted if it is determined that the related known functions may unnecessarily obscure the subject matter of the present invention as obvious matters to those skilled in the art.

Terms such as first and second may be used to describe various components, but the components should not be limited by the terms. The terms may only be used for the purpose of distinguishing one component from another. For example, a first element may be termed a second element, and similarly, a second element may be termed a first element, without departing from the scope of the present disclosure.

In this application, the terms "include" or "have" are intended to designate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other features It should be understood that the presence or addition of numbers, steps, operations, components, parts, or combinations thereof is not precluded.

Terms used in this application are only used to describe specific embodiments and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. Terms used in the embodiments of the present disclosure may be interpreted as meanings commonly known to those skilled in the art unless otherwise defined.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings.

1 is a schematic configuration diagram of an ultrasonic temperature measuring device according to an embodiment, FIG. 2 is a diagram showing the temperature measuring principle of FIG. 1, and FIG. 3 is a first sensing coil part when a pulse current is applied. It is a diagram showing a graph of an initial signal and a reflected signal detected in , and FIG. 4 is a schematic diagram of the first to fourth coils.

1 to 4, the ultrasonic temperature measuring device using the magnetostriction principle according to an embodiment of the present invention includes a wire 100, a reflection point unit 200, a pulse transmission unit 300, and a wire fixing unit. 400, a receiving unit 500, a tension adjusting unit 600, and the like may be included.

Magnetostriction refers to a phenomenon in which a magnetic domain inside a ferromagnetic material changes its appearance while being aligned in the direction of a magnetic field in a magnetic field or the opposite phenomenon. Magnetostriction is divided into one-dimensional magnetic field effect and two-dimensional magnetic field effect. Among the one-dimensional magnetic field effect, the Joule effect changes in the longitudinal direction when a magnetic field in one axis direction is applied around a ferromagnetic material, as the magnetic domains inside the material are aligned in the direction of the applied magnetic field. means a phenomenon This is typically referred to as the magnetostrictive effect.

The two-dimensional magnetic field effect includes the Wiedman effect and the like. The two-dimensional magnetic field effect is based on the one-dimensional magnetic field effect. For example, when a permanent magnet is placed around a ferromagnetic material, an axial magnetic field is formed, and when a current is applied directly to the material, a circumferential magnetic field is formed. Further, when the axial and circumferential magnetic fields are simultaneously applied, they meet at a certain point and a twisted spiral magnetic field in the direction of the sum vector is induced. And, through this, the material is twisted, which is called the Wiedmann effect.

The wire 100 is used as an ultrasonic waveguide and is made of a ferromagnetic magnetostrictive material. At this time, the diameter of the wire 100 is preferably 1 mm or less. When the wire 100 is used as an ultrasonic waveguide, it is possible to measure a long distance of 10 m or more and has excellent robustness to an external environment (dust, oil, etc.). In addition, since the wire 100 has a bendable shape, it can be fixed and installed in various shapes such as a straight line (flat surface) as well as a curved surface (curved surface).

In addition, the wire 100 according to one embodiment can solve problems such as installation difficulties due to existing structural limitations such as a bar having a diameter of 1 mm or less and a microspace. The wire 100 according to one embodiment uses a nickel-iron alloy, Ni ₅₀ Fe ₅₀ , and has a diameter of 1 mm. The wire 100 may be attached to a target for temperature measurement through, for example, a high-temperature adhesive. As a result, surface heat of the object to be measured can be smoothly transferred to the wire 100 .

The reflection point part 200 means a point where the pulse current applied through the pulse transmission part 300 is reflected. The reflection point unit 200 is fixedly disposed at any one position in the longitudinal direction of the wire 100 and provides a first magnetic field H _A in the axial direction with respect to the wire 100 around the wire 100 . The reflection point unit 200 may continuously apply a first magnetic field having the same intensity in the axial direction around the wire 100 . The reflection point unit 200 according to an embodiment has a cylindrical shape and may be formed of a magnetic material. In addition, the reflection point unit 200 may be fixed to the outer periphery of the wire 100, for example, to a space above the wire.

In addition, the temperature measuring device according to an embodiment may further include an auxiliary reflection point formed of at least one groove (not shown) formed on an outer circumferential surface of the wire 100 . At this time, a longitudinal wave may be formed at a point where the second magnetic field in the circumferential direction of the wire 100 moves and meets the groove. In addition, the change due to the longitudinal wave is detected through the first sensing coil unit 510, so that the temperature of the auxiliary reflection point unit can be measured.

According to an exemplary embodiment, when a plurality of reflection point portions 200 are formed, an average of temperature values of the reflection point portions 200 may be the temperature of the object to be measured. This makes it possible to compensate for the temperature deviation through multiple measurements when the temperature gradient in the length direction of the wire 100 is severe.

Also, according to another embodiment, when the reflection point portion 200 and at least one auxiliary reflection point portion are disposed, the average of each temperature value may be the temperature of the object to be measured. This is to compensate for the temperature deviation through multiple measurements when the temperature gradient in the length direction of the wire 100 is severe.

The pulse transmission unit 300 is disposed at one end of the wire 100 and applies a pulse current to the wire 100 to provide a circumferential second magnetic field H _C with respect to the wire 100 around the wire. The second magnetic field moves along the wire 100. Meanwhile, the pulse current is formed sequentially through, for example, a computer, a data acquisition device, and a current amplifier. When a pulse waveform to be applied is designed by the computer, the pulse waveform is output through the data acquisition device, which is input to an input of a current amplifier, converted into a pulse current having a voltage-to-current amplification ratio, and applied to the wire 100. Meanwhile, the magnitude of the second magnetic field also varies according to the magnitude of the applied pulse current.

The wire fixing part 400 is disposed on the other side of the wire 100 to fix the wire 100.

When the third magnetic field (H _T ) is formed at a point where the second magnetic field moves along the wire 100 and meets the reflection point unit 200, the receiving unit 500 detects a change by the third magnetic field. The temperature of the reflection point part 200 is measured through the sensing coil part 510 .

When the reflection point portion 200 is magnetic, the third magnetic field may be in the form of a spiral magnetic field corresponding to each ratio of the first magnetic field and the second magnetic field. Meanwhile, when a spiral magnetic field is instantaneously induced, a torsion wave is formed as the wire 100 is momentarily twisted. At this time, the receiving unit may measure the torsional displacement of the wire 100 through the second sensing coil unit 520 . Also, the receiving unit 500 may be disposed on one side of the wire 100.

When the second magnetic field moves along the wire 100, local deformation occurs in the longitudinal direction of the wire 100 from a microscopic point of view. As a result, when the second magnetic field generated by the pulse transmission unit 300 passes through the receiving unit 500, the receiving unit 500 can sense it in the form of an induced voltage. At this time, the detection time for the detected initial signal is referred to as T ₀ . Meanwhile, sensing of the induced voltage may be performed through the first sensing coil unit 510 .

When the second magnetic field continues to move along the wire 100 after passing through the receiving unit 500, it encounters the first magnetic field, which is a magnetic field in the axial direction by the reflection point unit 200. And, at that point, the third magnetic field (H _T ), which is a spiral magnetic field in the direction of the sum vector, is formed as the two types of magnetic fields meet at the same time. At this time, the wire 100 is momentarily twisted by the change by the third magnetic field and then returns to its original state. In addition, ultrasonic waves, which are torsional waves, are induced in the wire 100 by the instantaneous torsional deformation, which propagates in both directions of the wire 100.

When the torsion wave propagating toward the receiving unit 500 directly from the location where the torsion wave is generated passes through the first sensing coil unit 510, the detection time for the reflected signal detected at this time is referred to as T ₁ . Here, the time of propagation (TOF) of ultrasonic waves is T ₁ -T ₀ . TOF is the time when the first magnetic field moves from the first sensing coil part 510 to the position of the reflection point part 200 and the torsion wave formed at the reflection point part 200 returns to the first sensing coil part 510 means

On the other hand, the propagation speed of ultrasonic waves changes according to the temperature. Also, since the position of the reflection point portion 200 is fixed, the time of propagation (TOF) of ultrasonic waves is dependent on temperature. The difference in propagation time of ultrasonic waves according to temperature change (DTOF) is expressed as the relationship between the propagation time of ultrasonic waves (TOF _R ) at a certain day's reference temperature and the propagation time of ultrasonic waves (TOF _C ) calculated through the object of temperature measurement. can (DTOF = TOF _C - TOF _R ), that is, by measuring the time of propagation of ultrasonic waves (TOF _C ), it is possible to measure the ultrasonic temperature using the magnetostriction principle using DTOF.

The first sensing coil unit 510 according to an embodiment of the present invention may include any one of a first coil 511 of a solenoid structure and a second coil 512 of a uniaxial Helmholtz structure. The first coil 511 according to an embodiment may be formed by winding a self-bonding wire made of copper by 1000 turns. Also, a hole or air gap having a predetermined diameter may be formed in the center of the first coil 511 .

On the other hand, the Helmholtz structure of the second coil 512 can better detect minute changes in the magnetic field in detecting changes in the wire 100 compared to the solenoid structure of the first coil 511 . At this time, the condition of the shape of the second coil 512 is that two circular coils are arranged in parallel on the same axis, and the distance L2 between the two circular coils must be equal to the radius R of the circular coil.

In addition, the measurement deadband region A is formed at different positions according to the arrangement position of the first sensing coil unit 510, and the second sensing coil unit 520 may be disposed within the measurement deadband region A. there is. The measurement deadband region A is bound to exist in a measuring device using ultrasonic waves. This is because when the reflection point unit 200 is positioned close to the first sensing coil unit 510 in the receiving unit 500, the pulse signal applied from the pulse transmission unit 300 and the reflected signal by the reflection point unit 200 (ultrasound) may be caused by a phenomenon in which detection signals are not distinguished due to overlapping with each other.

In addition, when the reflection point unit 200 is located close to the other end of the wire 100, a torsion wave formed by the third magnetic field 1) moves from the reflection point unit 200 to the first sensing coil unit 510. The difference between direct reflection and 2) moving from the reflection point part 200 to the wire fixing part 400 and then reflecting from the wire fixing part 400 and moving to the first sensing coil part 510 become small As a result, a measurement deadband region (A) may occur.

The receiving unit 500 further includes a second sensing coil unit 520 to reduce the measurement deadband area A. The second sensing coil unit 520 may include any one of the third coil 521 having a 2-axis Helmholtz structure and the fourth coil 522 having a 3-axis Helmholtz structure. The biaxial structure means that a Helmholtz structure is further added in the vertical direction from the monoaxial structure. When the 1-axis structure is in the X-axis direction, the 2-axis structure is in either the XY-axis direction or the XZ-axis direction. At this time, the three-axis structure becomes the XYZ axis direction.

At this time, in the third coil 521 and the fourth coil 522, the torsion wave formed by the third magnetic field is reflected through the wire fixing part 400 and moves to the second sensing coil part 520. detect The torsion wave generates a magnetic field in two directions (the axial direction of the wire 100 and the circumferential direction of the wire 100). And, this forms a torsional displacement of the wire 100.

The second sensing coil unit 520 according to an embodiment may measure the torsional displacement of the wire 100 by detecting a change due to the third magnetic field. In order to measure torsional displacement of the conventional wire 100, a strain gauge has been installed and attached to a wire, etc. However, since the diameter of the wire 100 according to one embodiment is 1 mm or less, it is impossible to install the strain gauge. The second sensing coil unit 520 can solve this problem.

Also, the second sensing coil unit 520 may measure a magnetic field generated by a torsion wave. At this time, since the third coil 521 has a two-axis Helmholtz structure, voltage values can be measured for each axis (two). The second sensing coil unit 520 measures the magnetic field using the ratio and vector sum of each voltage value. Meanwhile, since the fourth coil 522 has a three-axis Helmholtz structure, voltage values can be measured for each axis (three).

The receiving unit 500 according to an embodiment is formed as a single component, measures the temperature of the reflection point 200 through the first sensing coil unit 510, and wire through the second sensing coil unit 520. Since the displacement of (100) and the third magnetic field can be measured, a plurality of physical quantities can be measured simultaneously.

At this time, it is preferable that the wire 100 passes through any one of the third coil 521 and the fourth coil 522 or is disposed side by side. The wire 100 may pass through the inner center of any one of the third coil 521 and the fourth coil 522 . In addition, the wire 100 may be disposed parallel to any one of the third coil 521 and the fourth coil 522 .

The receiving unit 500 may further include a signal processing unit 530 analyzing a reflected signal through the first sensing coil unit 510 . Here, the signal processing unit 530 may analyze the reflected signal through the second sensing coil unit 520 . Meanwhile, the signal processing unit 530 uses the first sensing coil unit 510 to detect the change due to the second magnetic field at the bth time (T ₀ ) and at the cth time (T _{1 )} when the change due to the third magnetic field is detected. ), a temperature measurement algorithm for measuring the temperature of the reflection point portion 200 may be embedded using the d-th time difference (TOF), which is a time difference between the time difference.

Specifically, the signal processing unit 530 pre-calculates the d1th time difference, which is the time difference between the b1th time at which a change by the second magnetic field is detected and the c1th time at which the change by the third magnetic field is detected in a certain day reference temperature. can do. Here, the d1 th time difference is TOF _R , which is the propagation time of ultrasonic waves at any one of the aforementioned reference temperatures.

In addition, the signal processing unit 530 calculates the d2th time difference, which is the time difference between the b2th time at which the change by the second magnetic field is detected and the c2th time at which the change by the third magnetic field is detected through the object of temperature measurement, in real time. can do. In addition, the d2th time difference is TOF _C , which is the propagation time of the above-described ultrasonic waves.

Through this, the signal processor 530 may measure the temperature of the reflection point by finally calculating the d3-th time difference, which is the time difference between the d2-th time difference and the d1-th time difference. And, the d3th time difference corresponds to the difference in propagation time (DTOF) of ultrasonic waves according to temperature change.

FIG. 5 is a diagram showing an oscilloscope graph of an excitation pulse applied and a reflection signal (detection signal) reflected from a reflection point in a temperature rise section of a magnetostrictive wire, and FIG. 6 is a view showing magnetostriction It is a diagram showing an oscilloscope graph of the pulse current (excitation pulse) applied in the temperature drop section of the wire and the reflected signal (detection signal) reflected from the reflection point.

FIG. 7 is a graph showing a trend line for a cubic exponential function in the temperature rising section of FIG. 1 , and FIG. 8 is a graph showing a trend line for a cubic polynomial function in the temperature decreasing section of FIG. 1 .

Referring to FIGS. 6 to 8 , the temperature measuring algorithm according to an embodiment is characterized in that a temperature rising section in which the temperature of a reflection point portion rises and a temperature falling section in which the temperature of a reflection point portion decreases are different from each other. That is, with respect to the temperature measurement object, the case where the temperature tends to rise and the case where the temperature tends to decrease are different. This is due to the fact that the material properties of the magnetostrictive wire 100 have hysteresis with respect to L, and that the propagation speed of ultrasonic waves is temperature dependent.

For example, in the temperature rising section, the temperature of the reflection point (T _{temperature rising section} ) preferably has a form of a cubic exponential function.

T _{temperature rise section} = a1*e ^(DTOF/a2) + b1*e ^(DTOF/b2) + c1*e ^(DTOF/c2) + d (where a1, b1, c1, a2, b2, c2, and d are arbitrary constants that vary depending on test conditions such as wire material, and e is an irrational natural logarithm) do.)

In addition, it is preferable that the temperature of the reflection point portion (T _{temperature falling section} ) in the temperature decreasing section has a form of a cubic polynomial function.

T _{temperature drop section} = a*(DTOF) ³ + b*(DTOF) ² + c*(DTOF) + d (Here, a, b, c and d are arbitrary constants that vary depending on test conditions such as wire material.)

Therefore, even if the position of the reflection point unit 200 is fixed, the effective signal point of each reflected signal varies according to the change in temperature. The signal processing unit 530 detects the c-th time T ₁ at which the change by the third magnetic field is detected through the effective signal point. Here, the valid signal point may correspond to a maximum voltage value when analyzing a region of interest among detected reflected signals. When the maximum voltage value is measured in this way, the time becomes the aforementioned T ₁ .

The tension control unit 600 changes the tension of the wire 100. The tension control unit 600 is disposed on one side of the wire 100 and may apply a certain amount of tension to the wire 100 according to conditions such as temperature and humidity of the surrounding environment.

An ultrasonic temperature measurement device using a magnetostriction principle according to an embodiment of the present invention may include a temperature measurement algorithm built into the receiving unit 500 . In addition, the temperature measurement method using the temperature measurement algorithm may include first to fourth steps.

9 is a schematic flowchart of a method for measuring temperature using an ultrasonic method according to an exemplary embodiment. Referring to this, the first step is a step of collecting reflected signals from the first sensing coil unit 510 .

The second step is a step of calculating the propagation time of the ultrasonic wave at a predetermined reference temperature, calculating the propagation time of the ultrasonic wave for the object to be measured, and then calculating the difference in the propagation time of the ultrasonic wave according to the temperature change. As described above, the difference in propagation time of ultrasonic waves according to temperature change (DTOF) is the difference between the propagation time of ultrasonic waves ( _TOFR ) at a certain day reference temperature and the propagation time of ultrasonic waves (TOF _C ) calculated through the object of temperature measurement. relationship can be expressed. (DTOF = TOF _C - TOF _R )

Then, the third step is a step of calculating each function having the propagation time difference (DTOF) of ultrasonic waves according to the temperature change in the temperature rising section and the temperature falling section as an input value. The temperature measurement algorithm according to an embodiment uses different functions in a temperature rising section and a temperature falling section. For example, as described above, the temperature of the reflection point portion (T _{temperature rise section} ) in the temperature rise section preferably has a form of a cubic exponential function. In addition, the temperature of the reflection point (T _{temperature falling section} ) in the temperature decreasing section preferably has the form of a cubic polynomial function as described above.

The fourth step is a step of calculating the real-time temperature of the object to be measured using a function. For example, when the object to be measured is located in a space where the temperature rises, the temperature of the object to be measured may be calculated as follows. The temperature can be calculated by entering DTOF in the formula below.

T _{temperature rise section} = a1*e ^(DTOF/a2) + b1*e ^(DTOF/b2) + c1*e ^(DTOF/c2) + d (where a1, b1, c1, a2, b2, c2, and d are arbitrary constants, and e is an irrational natural logarithm).

Although the above has been described with reference to the illustrated embodiments of the present invention, these are only examples, and those skilled in the art to which the present invention belongs can variously It will be apparent that other embodiments that are variations, modifications and equivalents are possible. Therefore, the true technical protection scope of the present invention should be determined by the technical spirit of the appended claims.

100: wire 200: reflection point
300: pulse transmission unit 400: wire fixing unit
500: receiving unit 600: tension adjusting unit
510: part of the first sensing coil 520: part of the second sensing coil
511: first coil 512: second coil
521: third coil 522: fourth coil
530: signal processing unit

A: measurement dead band

Claims (8)

magnetostrictive wires used as ultrasonic waveguides;
a reflection point portion fixedly disposed at any one position in the length direction of the wire;
a pulse transmitter disposed at one end of the wire and applying a pulse current to the wire to provide a second magnetic field around the wire in a circumferential direction with respect to the wire;
a wire fixing unit disposed on the other side of the wire and fixing the wire; and
When a third magnetic field is formed at a point where the second magnetic field moves along the wire and meets the reflection point, the temperature of the reflection point is measured through a first sensing coil that detects a change by the third magnetic field. Ultrasonic temperature measuring device using the magnetostriction principle including a; receiving unit to.
According to claim 1,
The ultrasonic temperature measuring device using the magnetostriction principle, characterized in that the reflection point portion is a magnetic material that provides a first magnetic field in the axial direction with respect to the wire around the wire.
According to claim 2,
When a plurality of reflection point portions are formed, the average temperature of each temperature value of the reflection point portion is the temperature of the object to be measured.
According to claim 1,
The receiving unit further includes a signal processing unit analyzing a reflected signal through the first sensing coil unit,
The signal processing unit measures the temperature of the reflection point by using a d-th time difference, which is a time difference between a b-th time at which a change by the second magnetic field is detected and a c-th time at which a change by the third magnetic field is detected. Ultrasonic temperature measurement device using the magnetostriction principle, characterized in that the temperature measurement algorithm is embedded.
The method of claim 4, wherein the signal processing unit,
Calculate in advance a d1th time difference, which is a time difference between a b1th time at which a change by the second magnetic field is detected and a c1th time at which a change by the third magnetic field is detected in a certain day reference temperature;
After calculating the d2th time difference, which is the time difference between the b2th time when the change by the second magnetic field is detected and the c2th time when the change by the third magnetic field is detected through the object of temperature measurement, in real time,
An ultrasonic temperature measuring device using the magnetostriction principle, characterized in that the temperature of the reflection point is measured by finally calculating the d3-th time difference, which is the time difference between the d2-th time difference and the d1-th time difference.
According to claim 4,
The temperature measurement algorithm is an ultrasonic type temperature measuring device using the magnetostriction principle, characterized in that the temperature rising section in which the temperature of the reflection point portion rises and the temperature falling section in which the temperature of the reflection point portion decreases are different from each other.
According to claim 1,
The receiving unit further includes a second sensing coil unit configured to measure a torsional displacement of the wire by detecting a change by the third magnetic field,
According to the arrangement position of the first sensing coil unit, measurement deadband regions are formed at different positions, and the second sensing coil unit is disposed within the measurement deadband region. measuring device.
A temperature measuring method using a temperature measuring algorithm built in a receiving unit among ultrasonic temperature measuring devices using the magnetostriction principle according to any one of claims 1 to 7,
A first step of collecting a reflected signal through the first sensing coil unit;
A second step of calculating the propagation time of the ultrasonic wave at a predetermined reference temperature, calculating the propagation time of the ultrasonic wave for the object to be measured, and then calculating the difference in the propagation time of the ultrasonic wave according to the temperature change;
A third step of calculating a function having, as an input value, a difference in propagation time of ultrasonic waves according to the temperature change in a temperature rising section and a temperature falling section, respectively; and
A fourth step of calculating the real-time temperature of the object to be measured using the function; an ultrasonic temperature measurement method using the magnetostriction principle, comprising:

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