KR20130137385A - Ultrasonic optical-fiber hydrogen detecting sensor - Google Patents

Abstract

The present invention provides an electric signal device for generating and detecting an electric signal; A piezoelectric element connected to the electric signal device to generate an ultrasonic wave when an electric signal is applied, and generate an electric signal when the ultrasonic signal is applied; And a plurality of optical fibers having one end connected to the piezoelectric element and provided with at least one hydrogen reaction portion at a predetermined portion, wherein the plurality of optical fibers output at least two times the output voltage of an electrical signal to hydrogen in a range of two or more times. It provides an ultrasonic optical fiber hydrogen detection sensor characterized by measuring the concentration of the high sensitivity.
According to the ultrasonic optical fiber hydrogen detection sensor of the present invention, by using a plurality of optical fibers with a hydrogen reaction unit can output the output voltage of the hydrogen detection sensor more than twice, the progress of the ultrasonic wave by the hydrogen reaction unit provided in the optical fiber The output voltage that is disturbed or lost due to the ultrasonic wave is reduced by more than two times, thereby improving the sensitivity of detecting hydrogen and improving the accuracy and stability of hydrogen detection.

Description

Ultrasonic Fiber-Optic Hydrogen Detecting Sensor {Ultrasonic Optical-fiber Hydrogen Detecting Sensor}

The present invention relates to an ultrasonic fiber hydrogen sensor, and more particularly, to an ultrasonic fiber hydrogen sensor that can detect hydrogen more sensitively using a plurality of optical fibers.

Sensor technology using optical fiber is widely used in various fields because it has several advantages over existing sensors. The mechanical characteristics of the optical fiber are not only light, small and fast, but also independent of external electrical noise and are not easily corroded. This feature is suitable for application to sensors or chemical or biological sensors embedded in structures, and is inserted into large-scale structures to detect stress, vibration or damage, or to determine the composition of chemicals. Various applications are possible across the field.

The basic measurement method of the optical fiber sensor uses a method of detecting the change by detecting a change in the wavelength of light reflected by a specific part by entering light into the optical fiber and analyzing the difference.

Conventional optical fiber sensors need to detect wavelength changes of several nm due to the nature of using light, and thus, expensive equipment capable of detecting and analyzing signals having short wavelengths is needed. In addition, the precision between the equipment and the detector is important for the accurate incidence of light onto the optical fiber and the accurate detection of the reflected light. The components of the sensor are complicated and expensive. For example, in the case of FBG fiber optic sensors, which are generally used in recent years, an additional process of equipping the optical fiber with a Bragg grating is needed to fabricate a sensing part in the optical fiber itself. By taking advantage of the difference in wavelengths, additional processes are needed to create the gaps needed for sensing and to maintain them.

That is, the conventional optical fiber sensor has a technical difficulty of accurately generating light of a specific wavelength because it uses light, and there are a lot of components to be provided, which is complicated in configuration and expensive.

In order to solve this problem, the prior art Korean Patent Registration 10-0923104 has proposed an optical fiber gas sensor that can easily detect the hydrogen gas using ultrasonic waves.

As shown in FIG. 1, the conventional optical fiber gas sensor detects gas by analyzing ultrasonic signals reflected by applying ultrasonic waves. The ultrasonic wave generated by applying an electrical signal to the optical fiber gas sensor piezoelectric element 10 propagates to the optical fiber 20 and converts the ultrasonic wave reflected and returned back into an electrical signal to output a voltage. At this time, the palladium 30 applied to the optical fiber 20 meets the hydrogen and causes a change in physical properties, thereby losing ultrasonic waves and detailing the output voltage. The concentration of hydrogen is confirmed through the reduced output voltage.

The conventional optical fiber hydrogen detection sensor is manufactured using one optical fiber, and as shown in FIG. 2, the output voltage of the hydrogen detection sensor manufactured using one optical fiber has a voltage peak of 10 kV. That is, it is difficult to set a consistent standard error range because the voltage output by using one optical fiber is limited and the output voltage which is decreased is several Hz. Therefore, there is a problem in that it is difficult to accurately measure the concentration of hydrogen, and the sensitivity is limited to detect hydrogen at a low concentration.

Korea Patent Registration: 10-0959245 (Notice date 2010.05.20)

Korea Patent Registration: 10-0923104 (Notice date 2009.10.27)

SUMMARY OF THE INVENTION The present invention has been made to solve the conventional problems,

An object of the present invention by outputting the output voltage of the electrical signal more than twice by using a plurality of optical fibers, it is possible to measure the concentration of hydrogen in a range of more than twice than the hydrogen detection sensor using a single optical fiber, and improved sensitivity Therefore, the present invention provides an ultrasonic optical fiber hydrogen sensor that can effectively detect low concentration of hydrogen.

Ultrasonic optical fiber hydrogen detection sensor according to an embodiment of the present invention provided to achieve the above object is an electrical signal device for generating and detecting an electrical signal; A piezoelectric element connected to the electric signal device to generate an ultrasonic wave when an electric signal is applied, and generate an electric signal when the ultrasonic signal is applied; And a plurality of optical fibers having one end connected to the piezoelectric element and provided with at least one hydrogen reaction portion at a predetermined portion, wherein the plurality of optical fibers output at least two times the output voltage of an electrical signal to hydrogen in a range of two or more times. It characterized by measuring the concentration of the highly sensitive.

The hydrogen reaction part includes a hydrogen contact part made of a material which is coated on an outer surface of the optical fiber and expands in contact with hydrogen, and a cover which surrounds the hydrogen contact part and passes the hydrogen but is not deformed by expansion of the hydrogen contact part. It is characterized in that provided in the optical fiber between the piezoelectric element and the other end of the optical fiber.

The hydrogen contact portion is made of a material that expands when contacted with hydrogen, and is preferably made of palladium (Pd: Palladium).

The cover has a lattice structure to allow hydrogen to pass therethrough, and is made of a metal or plastic material.

The hydrogen reaction unit is provided at the other end of the optical fiber, made of a material that reacts when in contact with hydrogen, preferably made of palladium (Pd: Palladium).

An electrical signal generating unit for generating an electrical signal, a piezoelectric element unit generating ultrasonic waves by receiving the electrical signal from the electrical signal generator, and generating an electrical signal when ultrasonic waves are applied, and an optical fiber having one end connected to the piezoelectric element unit And an electrical signal detection unit detecting an output voltage of an electrical signal generated by being connected to the piezoelectric element unit, wherein the optical fiber unit includes a plurality of optical fibers including a hydrogen reaction unit reacting with hydrogen; The plurality of optical fibers may output an output voltage of an electrical signal at least twice to measure the concentration of hydrogen in at least twice the range.

The hydrogen reaction unit is provided on the outer surface of the optical fiber at a predetermined interval, the hydrogen contact portion made of a material that is applied to the outer surface of the optical fiber and expands in contact with hydrogen, and surrounds the hydrogen contact portion and the hydrogen passes through the hydrogen contact portion It is characterized by consisting of a cover that is not deformed by expansion.

The hydrogen contact portion is made of a material that expands when contacted with hydrogen, and is preferably made of palladium (Pd: Palladium).

The cover has a lattice structure to allow hydrogen to pass therethrough, and is made of a metal or plastic material.

In addition, the hydrogen reaction unit is characterized in that made of palladium (Pd: Palladium) to react when in contact with hydrogen.

The piezoelectric element may include a first piezoelectric element, one end of which is connected to the electrical signal generator and the other end of which is connected to one end of the optical fiber, to generate ultrasonic waves when an electrical signal is applied from the electrical signal generator, and the other end of the optical fiber. The second piezoelectric element is connected to and applied to the ultrasonic wave propagated along the optical fiber to generate an electric signal.

The electrical signal detector is connected to the second piezoelectric element to detect an electrical signal generated by the second piezoelectric element and the first piezoelectric element is connected to the first piezoelectric element to detect an electrical signal generated by the first piezoelectric element. It characterized in that it comprises a second electrical signal detection unit.

According to the ultrasonic optical fiber hydrogen detection sensor of the present invention, by using a plurality of optical fibers with a hydrogen reaction unit can output the output voltage of the hydrogen detection sensor more than twice, the progress of the ultrasonic wave by the hydrogen reaction unit provided in the optical fiber The output voltage that is disturbed or lost due to the ultrasonic wave is reduced by more than two times, thereby improving the sensitivity of detecting hydrogen and improving the accuracy and stability of hydrogen detection.

Figure 1 is a schematic diagram showing a hydrogen detection sensor manufactured using a conventional optical fiber.
Figure 2 is a graph showing the output value of the hydrogen sensor using one optical fiber of FIG.
Figure 3 is a schematic diagram showing the configuration of an ultrasonic fiber hydrogen detection sensor according to an embodiment of the present invention.
4 is an enlarged cross-sectional view for explaining the hydrogen reaction unit of FIG.
Figure 5 is a cross-sectional view showing another example of the hydrogen reaction unit of the ultrasonic fiber optical hydrogen sensor according to an embodiment of the present invention.
Figure 6 is a schematic diagram showing the configuration of an ultrasonic fiber hydrogen detection sensor according to another embodiment of the present invention.
FIG. 7 is a schematic diagram illustrating another embodiment of the electrical signal detector of FIG. 6. FIG.
Figure 8 is a graph showing the output value of the ultrasonic fiber hydrogen detection sensor using a plurality of optical fibers.

These and other objects, features and other advantages of the present invention will become more apparent by describing in detail preferred embodiments of the present invention with reference to the accompanying drawings. Hereinafter, an ultrasonic fiber hydrogen detection sensor will be described in detail with reference to the accompanying drawings. For purposes of this specification, like reference numerals in the drawings denote like elements unless otherwise indicated.

Figure 3 is a schematic diagram showing the configuration of the ultrasonic fiber hydrogen sensor according to an embodiment of the present invention, Figure 4 is an enlarged cross-sectional view for explaining the hydrogen reaction unit of Figure 3, Figure 5 is an embodiment of the present invention It is sectional drawing which shows the other example of the hydrogen reaction part of the ultrasonic fiber-hydrogen sensor.

As shown in FIG. 3, the ultrasonic optical fiber hydrogen detection sensor according to the exemplary embodiment of the present invention includes an electric signal device 110, a piezoelectric element 120, and a plurality of optical fibers 130.

The electric signal device 110 is a device having both a means for generating an electric signal and a means for detecting an electric signal, and is connected to the piezoelectric element 120. The electrical signal device 110 generates an electrical signal, transfers the electrical signal to the piezoelectric element 120, and detects the electrical signal generated by the piezoelectric element 120.

The piezoelectric element 120 is connected to the electrical signal device 110, and when the electrical signal is received from the electrical signal device 110 generates an ultrasonic wave propagates to the plurality of optical fibers 130, the ultrasonic wave reflected back to the electrical signal To generate an electrical signal.

One end of each of the plurality of optical fibers 130 is connected to the piezoelectric element 120. In addition, at least one hydrogen reaction part 140 is provided on the outer surface of each optical fiber.

As shown in FIG. 4, the hydrogen reaction unit 140 may include a hydrogen contact unit 141 applied to the outer surfaces of the plurality of optical fibers 130 and a cover 142 surrounding the hydrogen contact unit 141. Hydrogen contact portion 141 is applied to the outer surface of the optical fiber 130 is used to expand the palladium in contact with the hydrogen, the cover 142 is wrapped around the outside of the hydrogen contact portion 141 but the hydrogen passes through the hydrogen contact portion 141 Material that is not deformed by expansion, for example, made of a material such as metal or plastic, it is preferable to form a lattice structure so that hydrogen passes.

The hydrogen contact portion 141 of the hydrogen reaction portion expands when hydrogen is contacted, and the expansion of the hydrogen contact portion 141 is limited to expansion to the outside by the cover 142 but expands inside to apply pressure to the optical fiber. . At this time, the ultrasonic waves traveling along the optical fiber are hindered by the pressure caused by the expansion of the hydrogen contact portion 141 and reflected back from the spot. The ultrasonic waves reflected and returned are converted into electrical signals by the piezoelectric element 120, and the converted electrical signals are detected by the electrical signal device 110. Here, the returned ultrasonic wave is hindered by the pressure due to the expansion of the hydrogen contact portion 141, the size of the signal detected by the electrical signal device 110 is reduced. At this time, the hydrogen contact portion 141 is the degree of expansion is changed according to the amount of hydrogen contacted, the magnitude of the pressure applied to the optical fiber is also changed, and also the magnitude of the signal detected by the electrical signal device 110 is also changed do.

Therefore, the ultrasonic waves traveling along the plurality of optical fibers 130 are disturbed twice by the expansion pressure of the hydrogen reaction unit 140, so that the magnitude of the signal detected by the electrical signal detection device 110 is more than twice. It becomes smaller.

Through this process, the detection of hydrogen around the optical fiber and the concentration of hydrogen are measured. In addition, since the speed of the ultrasonic waves can be obtained through calculation, and the time of the reflected ultrasonic waves can be measured, the position of the portion where the change is caused by contact with hydrogen can be identified through the speed of the ultrasonic waves and the time of the returned ultrasonic waves. .

As shown in FIG. 5, each of the hydrogen reaction parts 140 provided in the plurality of optical fibers may be formed of a material that is provided at the end of the optical fiber and reacts when contacted with hydrogen. Preferably it is provided at the end of the optical fiber, it may be made of palladium 143 that is absorbed and expanded when meeting the hydrogen.

When the ultrasonic wave generated in the piezoelectric element reaches the end of the optical fiber 130 and is reflected by the hydrogen reaction unit 140, the reflectance of the ultrasonic wave is affected by the difference in density between the optical fiber 130 and the hydrogen reaction unit 140. The palladium 143, which absorbs and expands hydrogen, has a low density, and as a result, reflectance of ultrasonic waves changes. At this time, the palladium 143 is expanded in accordance with the amount of hydrogen contacted, and thus the signal of the ultrasonic wave reflected. Through this process it is possible to determine the concentration of hydrogen based on the detected electrical signal.

Therefore, the ultrasonic waves traveling along the plurality of optical fibers 130 may decrease the ultrasonic reflectance due to expansion due to hydrogen absorption of the palladium 143 plated on the optical fibers 130 and reduce the output voltage by more than two times. As a result, the magnitude of the signal detected by the electric signal detection device is reduced by more than twice.

Figure 6 is a schematic diagram showing the configuration of an ultrasonic fiber hydrogen detection sensor according to another embodiment of the present invention.

As shown in FIG. 6, the ultrasonic optical fiber hydrogen detection sensor according to the exemplary embodiment of the present invention receives an electric signal from the electric signal generator 210 and an electric signal generator 210 to generate an electric signal. And the output voltage of the electric signal generated by connecting the piezoelectric element unit 220 to generate an electrical signal, the optical fiber unit 230 connected to one end of the piezoelectric element unit, and the piezoelectric element unit 220 when ultrasonic waves are applied. In the optical fiber hydrogen detection sensor including an electrical signal detection unit 240 to detect, the optical fiber unit 230 includes a plurality of optical fibers 131 having a hydrogen reaction unit 232 reacting with hydrogen, a plurality of optical fibers 131 is characterized in that for outputting the output voltage of the electrical signal more than two times to measure the concentration of hydrogen in more than twice the range.

The piezoelectric element unit 220 has a first end connected to the electrical signal generator 210 and the other end connected to one end of the optical fiber 231 to generate ultrasonic waves when an electrical signal is applied from the electrical signal generator 210. A piezoelectric element 221 and a second piezoelectric element 222 connected to the other end of the optical fiber 231 and generating ultrasonic signals when an ultrasonic wave propagated along the optical fiber 231 is applied thereto.

One end of each of the plurality of optical fibers 231 is connected to the first piezoelectric element 221, and the other end thereof is connected to the second piezoelectric element 222. And, the outer surface of the plurality of optical fibers 231 is provided with a hydrogen reaction unit 232 at a predetermined interval. Here, since the hydrogen reaction unit 232 is made of the same configuration as the embodiment shown in Figure 4 will not be described.

When the hydrogen reaction unit 232 meets hydrogen, the hydrogen reaction unit 232 expands, and the progress of the ultrasonic wave is interrupted by the pressure caused by the expansion of the hydrogen reaction unit 232 so that the magnitude of the signal detected by the electric signal detection unit 240 becomes small. do.

As illustrated in FIG. 6, the electrical signal detector 240 may be connected to the second piezoelectric element 222 to detect an output voltage output from the second piezoelectric element 222, and as illustrated in FIG. 7. The first electrical signal detector 241 is connected to the second piezoelectric element, and the second electrical signal detector 242 is connected to the first piezoelectric element to detect the output voltage output from each piezoelectric element.

Ultrasonic waves generated by the first piezoelectric element 221 advance along the plurality of optical fibers 231, and the first electrical signal detector 241 may be provided with an expansion pressure of the hydrogen reaction unit 232 provided in the plurality of optical fibers 231. As a result, the output voltage detected by the ultrasonic wave reaching the second piezoelectric element 222 is detected in the state of being interrupted and lost.

In addition, the second electrical signal detection unit 242 is interrupted by the pressure generated by the expansion of the hydrogen reaction unit 232 while the ultrasonic wave generated in the first piezoelectric element 221 progresses along the plurality of optical fibers 231. It may also bounce back from the spot. Accordingly, the reflected ultrasonic waves are converted into electrical signals by the first piezoelectric element 221, and the converted electrical signals are detected.

The ultrasonic optical fiber hydrogen detection sensor generates ultrasonic waves in the first piezoelectric element 221 to which an electrical signal is applied from the electrical signal generator 210, and the ultrasonic waves generated in the first piezoelectric element 221 are a plurality of optical fibers 231. Proceeds along to reach the second piezoelectric element 222 connected to the other end. At this time, the ultrasonic wave traveling along the optical fiber 231 by the hydrogen reaction unit 232 provided in the plurality of optical fibers 231 is prevented from progressing due to the expansion pressure of the hydrogen reaction unit 232, thereby detecting the electrical signal 240. ) Decreases the magnitude of the detected signal. In particular, the ultrasonic waves traveling along the plurality of optical fibers 231 are disturbed twice by the expansion pressure of the hydrogen reaction unit 232, so that the magnitude of the signal detected by the electrical signal detection unit 240 is smaller than twice. You lose.

On the other hand, the hydrogen reaction unit 232 may be made of a material that reacts when contacted with hydrogen, preferably made of palladium that is absorbed and expanded when it meets hydrogen. In this case, when the ultrasonic waves generated by the first piezoelectric element 221 are reflected by the hydrogen reaction unit 232 of the optical fiber, the reflectance of the ultrasonic waves may be affected by the difference between the densities of the optical fiber 231 and the hydrogen reaction unit 232. do. Therefore, the hydrogen reaction unit 232 absorbing and expanding hydrogen has a low density, and as a result, the reflectance of the ultrasonic wave is changed. At this time, the hydrogen reaction unit 232 is expanded in accordance with the amount of hydrogen in contact, and accordingly the signal of the ultrasonic wave reflected. In addition, the ultrasonic signal is changed back to the electrical signal in the second piezoelectric element 222, the electrical signal is detected by the connected electrical signal detector 240, it is possible to determine the concentration of hydrogen based on the detected electrical signal.

Therefore, the ultrasonic waves traveling along the plurality of optical fibers 231 reduce the output voltage output by the ultrasonic waves lost when hydrogen is adsorbed to the palladium 232 plated on the optical fiber, and at the same time, the electrical signal detector The magnitude of the signal detected at 240 becomes smaller than twice.

8 is a graph illustrating output values of an ultrasonic fiber hydrogen sensor using a plurality of optical fibers.

As shown in FIG. 8, the ultrasonic optical fiber hydrogen detection sensor of the present invention uses a plurality of optical fibers provided with a hydrogen reaction unit so that the progress of ultrasonic waves along the optical fiber is obstructed or lost, and thus the magnitude of the signal detected by the electrical signal detection device. It can be seen that becomes 2 times smaller.

The output voltage of the singular ultrasonic fiber optical fiber hydrogen sensor shown in FIG. 2 has a voltage peak of 10 mv, while the hydrogen sensor manufactured using a plurality of optical fibers shown in FIG. 8 is 30mv to 35mv, which is more than twice the output voltage. It can be confirmed that it has a voltage peak point of. In addition, when hydrogen is adsorbed on the palladium plated on the optical fiber it can be seen that the output voltage output by the ultrasonic wave is also reduced by more than two times.

Hydrogen sensors that can be used for safety should have high sensitivity to detect hydrogen at concentrations of less than 4% as well as at concentrations of 1%. Conventional singular ultrasonic fiber hydrogen sensor has a limitation of the output voltage, it is difficult to set a consistent standard error range. However, since the ultrasonic fiber hydrogen sensor using a plurality of optical fibers can measure hydrogen in the range of more than twice the output voltage of the single-type hydrogen sensor, the concentration of hydrogen can be measured by setting a certain error range. In addition, it can serve as a more stable and sensitive sensor.

As described above, the present invention can output the output voltage of the hydrogen detection sensor more than twice by using a plurality of optical fibers, and also the ultrasonic wave is interrupted or the ultrasonic wave is lost by the hydrogen reaction unit provided in the optical fiber. The output voltage is also reduced by more than two times, which makes hydrogen detection more accurate, stable and sensitive.

Although the preferred embodiments of the present invention have been described, the present invention is not limited to the specific embodiments described above. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the appended claims, And equivalents may be resorted to as falling within the scope of the invention.

110: electric signal device 120: piezoelectric element
130: optical fiber 140: hydrogen reaction unit
141: hydrogen contact portion 142: cover
143: palladium 210: electric signal generator
220: piezoelectric element portion 221: first piezoelectric element
222: second piezoelectric element 230: optical fiber portion
231: optical fiber 232: hydrogen reaction unit
240: electrical signal detector 241: first electrical signal detector
242: second electrical signal detection unit

Claims (16)

An electric signal device for generating and detecting an electric signal;
A piezoelectric element connected to the electric signal device to generate an ultrasonic wave when an electric signal is applied, and generate an electric signal when the ultrasonic signal is applied;
And a plurality of optical fibers having one end connected to the piezoelectric element and provided with at least one hydrogen reaction part at a predetermined portion.
The plurality of optical fibers output the output voltage of the electrical signal more than two times, the ultrasonic optical fiber hydrogen detection sensor, characterized in that to measure the concentration of hydrogen in a sensitivity more than two times high. The method of claim 1,
The hydrogen reaction part includes a hydrogen contact part made of a material which is coated on an outer surface of the optical fiber and expands in contact with hydrogen, and a cover which surrounds the hydrogen contact part and passes the hydrogen but is not deformed by expansion of the hydrogen contact part. Ultrasonic fiber hydrogen detection sensor, characterized in that provided in the optical fiber between the piezoelectric element and the other end of the optical fiber. 3. The method of claim 2,
The hydrogen contact portion of the ultrasonic optical fiber hydrogen sensor, characterized in that made of a material that expands when in contact with hydrogen. The method of claim 3, wherein
Ultrasonic optical fiber hydrogen sensor, characterized in that the hydrogen contact portion made of palladium (Pd: Palladium). 3. The method of claim 2,
The cover has a lattice structure to allow hydrogen to pass through, and the ultrasonic optical fiber hydrogen sensor, characterized in that made of a metal or plastic material. The method of claim 1,
The hydrogen reaction unit is provided at the other end of the optical fiber, ultrasonic fiber hydrogen sensor, characterized in that made of a material that reacts when in contact with hydrogen hydrogen. 7. The method according to claim 1 or 6,
The hydrogen reaction unit is an ultrasonic optical fiber hydrogen sensor, characterized in that made of palladium (Pd: Palladium) that reacts when in contact with hydrogen. An electrical signal generating unit for generating an electrical signal, a piezoelectric element unit generating ultrasonic waves by receiving the electrical signal from the electrical signal generator, and generating an electrical signal when ultrasonic waves are applied, and an optical fiber having one end connected to the piezoelectric element unit In the optical fiber hydrogen detection sensor comprising an electrical signal detection unit for detecting the output voltage of the electrical signal generated connected to the piezoelectric element unit,
The optical fiber unit includes a plurality of optical fibers provided with a hydrogen reaction unit for reacting with hydrogen, wherein the plurality of optical fibers output an output voltage of an electrical signal at least twice to measure the concentration of hydrogen in at least twice the range. Ultrasonic fiber optic hydrogen sensor. The method of claim 8,
The hydrogen reaction unit is an ultrasonic optical fiber hydrogen sensor, characterized in that provided on the outer surface of the optical fiber at a predetermined interval. 10. The method according to claim 8 or 9,
The hydrogen reaction unit is formed of a cover which is coated on the outer surface of the optical fiber is made of a material that expands when contacted with hydrogen, and surrounds the hydrogen contact portion and the hydrogen is passed through but not deformed by expansion of the hydrogen contact portion. Ultrasonic fiber optic hydrogen sensor characterized in that. 11. The method of claim 10,
The hydrogen contact portion of the ultrasonic optical fiber hydrogen sensor, characterized in that made of a material that expands when in contact with hydrogen. The method of claim 11,
Ultrasonic optical fiber hydrogen sensor, characterized in that the hydrogen contact portion made of palladium (Pd: Palladium). 11. The method of claim 10,
The cover has a lattice structure to allow hydrogen to pass through, and the ultrasonic optical fiber hydrogen sensor, characterized in that made of a metal or plastic material. 10. The method according to claim 8 or 9,
The hydrogen reaction unit is an ultrasonic optical fiber hydrogen sensor, characterized in that made of palladium (Pd: Palladium) that reacts when in contact with hydrogen. The method of claim 8,
The piezoelectric element may include a first piezoelectric element, one end of which is connected to the electrical signal generator and the other end of which is connected to one end of the optical fiber, to generate ultrasonic waves when an electrical signal is applied from the electrical signal generator, and the other end of the optical fiber. Ultrasonic fiber hydrogen detection sensor, characterized in that consisting of a second piezoelectric element connected to and applied to the ultrasonic wave traveling along the optical fiber to generate an electrical signal. The method of claim 15,
The electrical signal detector is connected to the second piezoelectric element to detect an electrical signal generated by the second piezoelectric element and the first piezoelectric element is connected to the first piezoelectric element to detect an electrical signal generated by the first piezoelectric element. Ultrasonic optical fiber hydrogen detection sensor comprising a second electrical signal detection unit.

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