JPH05188080A - Operating fluid and sensor structure using this operating fluid - Google Patents

Abstract

PURPOSE:To improve responsiveness and reproducibility. CONSTITUTION:Sensor structure is formed of a U-shape communicating tube 2 filled with an operating fluid 1; primary coils 3a, 3b and secondary coils 4a, 4b wound on the outer peripheral side of both legs of the communicating tube 2; a.c. power for applying an alternating current to the primary coils 3a, 3b; and a measuring apparatus to be connected to the secondary coils 4a, 4b. The alternating current is applied to the primary coils 3a, 3b to measure electro motive force generated to the secondary coils 4a, 4b, thus detecting the movement of the operating fluid.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a working fluid and a sensor structure using the working fluid, and more particularly to a working fluid excellent in response and reproducibility and a sensor structure using the working fluid.

[0002]

2. Description of the Related Art Conventionally, as a sensor structure using a magnetic fluid, a sensor structure as shown in FIG. 10 is known. The sensor structure shown in FIG.
As disclosed in Japanese Patent Laid-Open No. 63-145933, a magnetic fluid 51 is filled in a non-magnetic U-shaped communication pipe 52, and the legs 52a and 52b of the non-magnetic communication pipe 52 have the normal liquid level of the magnetic fluid. Primary windings 53a, 53b near a reference liquid surface
The secondary windings 54a and 54b are arranged at the ends of the communication tube 52 so as to be aligned with the primary windings 53a and 53b in the axial direction.

The induced electromotive force generated in one secondary winding 54a and the induced electromotive force generated in the other secondary winding 54b are caused by the magnetic flux generated by flowing an alternating current through the primary windings 53a and 53b. The pressure introduced from the openings 55a and 55b can be measured by detecting the potential difference.

However, since the magnetic fluid 51 has a very good wettability, the magnetic fluid 51 adheres to the inner wall of the U-shaped communication pipe 52 when the pressure is introduced into the openings 55a and 55b. However, there is a problem that the response and reproducibility are deteriorated and a measurement error occurs.

The present invention solves the above-mentioned problems of the conventional ones, and an object thereof is to provide a working fluid excellent in response and reproducibility and a sensor structure using the working fluid. To do.

[0006]

In order to achieve the above-mentioned object, the present invention is a working fluid in which a surfactant-adsorbing magnetic microparticle is dispersed in a dispersion medium, wherein the surfactant-adsorbing magnetic microparticle is A means is adopted in which an appropriate surfactant is adsorbed around microcapsules containing an oily substance containing fine particles of a magnetic substance. A non-magnetic case filled with the working fluid, a primary winding and a secondary winding located near the standard liquid surface of the working fluid and wound around the outer circumference of the case, and the primary winding. An AC power supply for applying an AC current to the wire and a measuring device connected to the secondary winding. An AC current is applied to the primary winding to measure the electromotive force generated in the secondary winding. The means for detecting the movement of the working fluid is adopted. Also,
A non-magnetic case that is not mixed with the working fluid and the other working fluid and is filled with another fluid having a different specific gravity; Rotating primary and secondary windings,
An alternating current power source for applying an alternating current to the primary winding;
And a measuring device connected to the secondary winding, wherein an alternating current is applied to the primary winding to measure an electromotive force generated in the secondary winding to detect movement of the working fluid. It was done. Further, a laterally placed non-magnetic case filled with the working fluid, a first winding and a second winding wound around the outer peripheral side of the case, the first winding and the second winding A bridge circuit is formed from the windings, and the bridge circuit is composed of an alternating current power supply that applies an alternating current to the bridge circuit. The voltage of the bridge circuit is measured to detect the movement of the working fluid. A lateral non-magnetic case filled with a working fluid and other fluids having different specific gravities and not mixed with each other, and a first winding and a second winding wound around the outer circumference of the case. A bridge circuit composed of a winding wire and the first winding wire and the second winding wire, and an alternating current power supply for applying an alternating current to the bridge circuit; and a voltage generated in the bridge circuit is measured to measure the voltage. Detects movement of working fluid It adopted the means of. In addition, a non-magnetic case filled with the working fluid, a base placed inside the case with a part of the legs immersed in the working fluid, and a winding on the base of the base. A primary winding that is rotated, a secondary winding that is wound around a leg of the base, and an AC power supply that applies an alternating current to the primary winding,
And a measuring device connected to the secondary winding, for applying an alternating current to the primary winding to measure an electromotive force generated in the secondary winding to detect movement of the working fluid. Is adopted. A non-magnetic case that does not mix with the working fluid and this working fluid and is filled with another fluid having a different specific gravity, and a part of the legs is immersed in the working fluid and other fluid inside the case. The base placed in the above state, the primary winding wound around the base of the base, the secondary winding wound around the leg of the base,
It is composed of an AC power source for applying an alternating current to the secondary winding and a measuring instrument connected to the secondary winding. The alternating current is applied to the primary winding to generate an electromotive force generated in the secondary winding. The means for measuring and detecting the movement of the working fluid is adopted.

[0007]

The present invention, by adopting the above means,
When the working fluid filled in the non-magnetic case moves, a voltage is generated, and by measuring this voltage, the pressure, inclination, acceleration, etc. that cause the movement of the working fluid can be detected. Further, since this working fluid is a dispersion medium in which the surfactant-adsorbed magnetic fine particles are dispersed, it is difficult for the working fluid to adhere to the inner wall of the case, and the sensor has good responsiveness and reproducibility.

[0008]

Embodiments of the present invention shown in the drawings will be described below. FIG. 1 shows an embodiment of a working fluid according to the present invention, which working fluid is disclosed in Japanese Examined Patent Publication No. 38-1489.
A suitable surfactant was adsorbed around the magnetic capsule shown in No. 8 to form a surfactant-adsorbed magnetic microparticle, and this surfactant-adsorbed magnetic microparticle was dispersed in a dispersion medium such as oil or water. It is a thing.

The magnetic capsule shown in Japanese Patent Publication No. 38-14898 is a microcapsule containing an oily substance containing fine particles of a magnetic substance.

In order to form the surfactant-adsorbed magnetic fine particles, first, as shown in the manufacturing process diagram of FIG. 1, the magnetic capsule is first put into an aqueous solution of sodium oleate and heated and stirred at 90 ° C. Hold for 30 minutes and cool to 40 ° C or below.

After decantation, filtration and drying are carried out to produce a surfactant-adsorbed magnetic fine particle.

Further, when the surfactant-adsorbed magnetic fine particles thus produced are dispersed in a dispersion medium such as oil or water, a working fluid is formed.

Next, an embodiment of a sensor structure using the working fluid will be described. FIG. 2 shows a first embodiment of the sensor structure according to the present invention. This sensor structure comprises a U-shaped communicating pipe 2 which is a non-magnetic case filled with the working fluid 1 and Both legs 2a of the communication pipe 2,
One primary winding 3a and the other primary winding 3b arranged near the reference liquid surface which is the liquid surface of the working fluid 1 located in 2b in the normal state, and these primary windings 3a and 3b. And one of the secondary windings 4a and the other secondary winding 4b arranged at the end of the communication tube 2 aligned in the axial direction.

An alternating current flows through the primary windings 3a and 3b, and the secondary winding 4
A measuring device for measuring electromotive force is connected to a and 4b.

Next, the operation of the sensor structure constructed as above will be described below. First, when an alternating current is applied to both of the primary windings 3a and 3b, the primary windings 3
Magnetic flux is generated in a and 3b, and induced electromotive force is generated in the secondary windings 4a and 4b by the magnetic flux.

Then, the potential difference between the induced electromotive force generated in one of the secondary windings 4a and the induced electromotive force generated in the other secondary winding 4b is detected, and the change in the liquid level of the working fluid 1 is measured. be able to.

Therefore, for example, if pressure is introduced from one opening 5a of the communicating pipe 2, the liquid level changes due to the introduced pressure, and the opening of the communicating pipe 2 is detected by detecting this change in liquid level. The pressure introduced into the part 5a can be measured.

The working fluid 1 is a dispersion medium in which the surfactant adsorbing magnetic fine particles are dispersed, and is well separated from the communication pipe 2, and the working fluid 1 adheres to the inner wall of the communication pipe 2. Therefore, the responsiveness and reproducibility are improved, and the measurement accuracy of the sensor is improved.

FIG. 3 shows a second sensor structure according to the present invention.
Is shown, and this embodiment is a modification of the first embodiment, and the same portions will be described below by using the same reference numerals.

This sensor structure has a U-shaped case which is a non-magnetic case filled with the working fluid 1 and another fluid 11 which does not mix with the working fluid 1 and has a larger specific gravity than the working fluid 1. The communication pipe 2 and the primary winding 13 arranged on the side of the working fluid 1 and near the reference liquid surface of the working fluid 1 located on one leg 2 a of the communication pipe 2.
And the secondary windings 14a, 14 which are arranged so as to be axially aligned with the primary winding 13 and sandwich the primary winding 13 therebetween.
It consists of b and.

The other liquid 11 is the working fluid 1
If the dispersion medium of the working fluid 1 is oil, the other liquid 11 may be water. An alternating current flows through the primary winding 13, and a measuring device for measuring electromotive force is connected to the secondary windings 14a and 14b.

Next, the operation of the sensor structure constructed as described above will be described below. First, when an alternating current is passed through the primary winding 13, a magnetic flux is generated in the primary winding 13, and the magnetic flux causes an induced electromotive force in the secondary windings 14a and 14b.

Then, the potential difference between the induced electromotive force generated in one secondary winding 14a and the induced electromotive force generated in the other secondary winding 14b is detected, and the change in the liquid level of the working fluid 1 is measured. be able to.

Therefore, for example, if a pressure is introduced from the other opening 5b on the other liquid 11 side of the communication pipe 2, the liquid level changes due to the introduced pressure, and by detecting this change in the liquid level. The pressure introduced into the other opening 5b of the communication pipe 2 can be measured.

The working fluid 1 is a dispersion medium in which the surfactant-adsorbed magnetic fine particles are dispersed, and is well separated from the communication pipe 2, and the working fluid 1 adheres to the inner wall of the communication pipe 2. Therefore, the responsiveness and reproducibility are improved, and the measurement accuracy of the sensor is improved.

Further, this embodiment requires less working fluid 1 as compared with the first embodiment, and is economical.

FIG. 4 shows a third sensor structure according to the present invention.
The working fluid used in this embodiment is the same as the working fluid 1 used in the first embodiment, so the same reference numerals are used.

In this sensor structure, a cylindrical sealed container 22 which is a non-magnetic case in which the working fluid 1 is filled and the opening is closed, and the outer circumference of the sealed container 22 are wound and the operation is performed. The primary winding 23 arranged near the reference liquid surface of the fluid 1 and one of the primary windings wound around the outer circumference of the primary winding 23 and arranged side by side in the axial direction across the reference liquid surface. Secondary winding 24a and the other secondary winding 24
It consists of b and.

An alternating current flows through the primary winding 23, and both the secondary windings 24a, 24a.
A measuring instrument for measuring electromotive force is connected to b.

Next, the operation of the sensor structure configured as described above will be described below. First, when an alternating current is passed through the primary winding 23, a magnetic flux is generated in the primary winding 23, and this magnetic flux causes an induced electromotive force in both the secondary windings 24a and 24b.

Then, the potential difference between the induced electromotive force generated in one secondary winding 24a and the induced electromotive force generated in the other secondary winding 24b is detected, and the change in the liquid level of the working fluid 1 is measured. be able to.

Therefore, for example, when the sealed container 22 is tilted, the liquid level changes, and the tilt of the sealed container 22 can be measured by detecting the change in the liquid level, and when acceleration acts on the sealed container 22. Acceleration can be measured by changing the liquid level.

The working fluid 1 is a dispersion medium in which the surfactant-adsorbing magnetic fine particles are dispersed, and is well separated from the sealed container 22, and the working fluid 1 adheres to the inner wall of the sealed container 22. Therefore, the responsiveness and reproducibility are improved, and the measurement accuracy of the sensor is improved.

FIG. 5 shows a fourth sensor structure according to the present invention.
Is shown, which is a modification of the third embodiment described above, in which the sealed container is filled with not only the working fluid but also another fluid which is immiscible therewith,
Since other configurations are similar to those of the third embodiment, the same portions will be described below by using the same reference numerals.

This sensor structure has a cylindrical shape which is a non-magnetic case in which the working fluid 1 and another fluid 21 that is not mixed with the working fluid 1 and has a larger specific gravity than the working fluid 1 are filled and the opening is closed. Of the sealed container 22, a primary winding 23 wound around the outer peripheral side of the sealed container 22 and arranged near the reference liquid surface of the working fluid 1, and an outer peripheral side of the primary winding 23. It is composed of one secondary winding 24a and the other secondary winding 24b which are wound and arranged side by side in the axial direction with the reference liquid surface sandwiched therebetween.

An alternating current flows through the primary winding 23, and both the secondary windings 24a, 24a
A measuring instrument for measuring electromotive force is connected to b.

Next, the operation of the sensor structure configured as described above will be described below. First, when an alternating current is passed through the primary winding 23, a magnetic flux is generated in the primary winding 23, and this magnetic flux causes an induced electromotive force in both the secondary windings 24a and 24b.

Then, the potential difference between the induced electromotive force generated in one secondary winding 24a and the induced electromotive force generated in the other secondary winding 24b is detected, and the change in the liquid level of the working fluid 1 is measured. be able to.

Therefore, for example, when the sealed container 22 is tilted, the liquid level changes, and the tilt of the sealed container 22 can be measured by detecting the change in the liquid level, and when acceleration acts on the sealed container 22. Acceleration can be measured by changing the liquid level.

The working fluid 1 is a dispersion medium in which the surfactant-adsorbing magnetic fine particles are dispersed, and the working fluid 1 is well separated from the sealed container 22 and the working fluid 1 adheres to the inner wall of the sealed container 22. Therefore, the responsiveness and reproducibility are improved, and the measurement accuracy of the sensor is improved.

Further, the working fluid 1 floats above the other fluid 21 and moves largely in response to the change in the inclination and acceleration, and the measurement accuracy as a sensor is the same as that of the third embodiment. The sensor structure is improved.

FIG. 6 shows a fifth sensor structure according to the present invention.
In this sensor structure, a sealed container 32 having a predetermined width, which is a non-magnetic case filled with the working fluid 1 and having a substantially semicircular cross section, and the sealed container 3 are shown.
2 and a winding 33 wound around the outer peripheral side.

The winding 33 is connected to the sealed container 3
The first winding 33a wound on the left side of 2 and the second winding 33b wound on the right side constitute a bridge circuit as shown in FIG.

Further, the hermetically sealed container 32 is placed horizontally with the spherical portion facing upward, and bubbles are formed in the upper portion.

An alternating current flows through the bridge circuit, and the contact point b of the bridge circuit,
A measuring device for measuring electromotive force is connected between b.

Next, the operation of the sensor structure configured as described above will be described below. First, an alternating current is applied to the bridge circuit, and the resistors R1 and R2 of the bridge circuit are
Is adjusted to set the voltage between the contacts b and b to zero.

When the working fluid 1 filled in the hermetically sealed container 32 moves, the inductances of the first winding 33a and the second winding 33b change, the balance of the bridge circuit is lost, and the contact b , B is generated, and the change in the liquid level of the working fluid can be measured by detecting the voltage.

Therefore, when the sealed container 32 is tilted, the working fluid 1 moves, and the first winding 33a and the second winding 3 are moved.
Since the inductance of 3b changes, the direction of inclination can be detected, and the degree of inclination can be measured by the voltage between the contacts b.

The working fluid 1 is a dispersion medium in which the surfactant-adsorbing magnetic fine particles are dispersed, and is well separated from the sealed container 32, and the working fluid 1 adheres to the inner wall of the sealed container 32. Therefore, the responsiveness and reproducibility are improved, and the measurement accuracy of the sensor is improved.

FIG. 7 shows a sixth sensor structure according to the present invention.
Is shown, which is a modification of the fifth embodiment, in which not only the working fluid but also other fluids that are immiscible with it are enclosed together in a sealed container, Since the other structure is the same as that of the fifth embodiment, the same portions will be described below by using the same reference numerals.

This sensor structure is a non-magnetic case having a predetermined width in which the working fluid 1 and another fluid 31 that is not mixed with the working fluid 1 and has a specific gravity larger than that of the working fluid 1 are enclosed. It is composed of a semicircular hermetic container 32 and a winding 33 wound around the outer periphery of the hermetic container 32.

The winding 33 is connected to the sealed container 3
The first winding 33a is wound on the left side of the second winding 2, and the second winding 33b is wound on the right side of the second winding 33a to form a bridge circuit as shown in FIG.

Further, the hermetically sealed container 32 is placed horizontally with the spherical surface facing upward, and the working fluid 1 is located on the upper part.

An alternating current flows through the bridge circuit, and the contact point b of the bridge circuit,
A measuring device for measuring electromotive force is connected between b.

Next, the operation of the sensor structure configured as described above will be described below. First, an alternating current is applied to the bridge circuit, and the resistors R1 and R2 of the bridge circuit
Is adjusted to set the voltage between the contacts b and b to zero.

When the working fluid 1 filled in the hermetically sealed container 32 moves, the inductances of the first winding 33a and the second winding 33b change, the balance of the bridge circuit is lost, and the contact b , B is generated, and the change in the liquid level of the working fluid can be measured by detecting the voltage.

Therefore, when the sealed container 32 is tilted, the working fluid 1 moves, and the first winding 33a and the second winding 3 are moved.
Since the inductance of 3b changes, the direction of inclination can be detected, and the degree of inclination can be measured by the voltage between the contacts b.

The working fluid 1 is a dispersion medium in which the surfactant-adsorbing magnetic fine particles are dispersed, and is well separated from the sealed container 32, and the working fluid 1 adheres to the inner wall of the sealed container 32. Therefore, the responsiveness and reproducibility are improved, and the measurement accuracy of the sensor is improved.

Further, the working fluid 1 floats on the other fluid 31 and moves largely in response to the change in the inclination, and the measurement accuracy as a sensor is the sensor in the fifth embodiment. Better than structure.

FIG. 8 shows a seventh embodiment of the sensor structure according to the present invention.
Is shown, in which the sensor structure is a container 42 which is a non-magnetic case filled with the working fluid 1;
A chair-type base 45 in which a part of the legs 45b, 45c, 45d, 45e extending from the base 45a in the container 42 is embedded in the working fluid 1, and the base 45a.
The primary windings 43a and 43b wound around the base and the primary windings 43a and 43b which are wound around the base portion 45a so as to hang around the primary windings 43a and 43b.
The secondary windings 43c and 43d and the leg portions 4 of each of the four windings
Secondary winding 44 wound around 5b, 45c, 45d, 45e
b, 44c, 44d and 44e.

Then, the primary windings 43a, 43b, 4
An alternating current flows through 3c and 43d,
Measuring devices for measuring electromotive force are connected to the secondary windings 44b, 44c, 44d and 44e.

Next, the operation of the sensor structure configured as described above will be described below. First, when an alternating current is passed through the primary windings 43a, 43b, 43c, 43d,
A magnetic flux is generated in the primary windings 43a, 43b, 43c, 43d, and due to this magnetic flux, the secondary windings 44b, 44c, 4
Induced electromotive force is generated in 4d and 44e.

The four legs 45b, 45c, 45
secondary windings 44b and 44 wound around d and 45e, respectively
The change in the liquid level of the working fluid 1 can be measured by detecting the differential potential of the induced electromotive force generated in c, 44d, and 44e.

Therefore, for example, when the container 42 is tilted, the liquid level changes, and the tilt of the container 42 can be measured by detecting the change in the liquid level.

The working fluid 1 is a dispersion medium in which surfactant-adsorbing magnetic fine particles are dispersed.
Since it is well separated from the working fluid 1 and the working fluid 1 does not adhere to the inner wall of the container 42, the responsiveness and reproducibility are improved, and the measurement accuracy as a sensor is improved.

Further, in this embodiment, the leg portion 45
secondary winding 44 on each of b, 45c, 45d, and 45e.
Since b, 44c, 44d, and 44e are wound, it is possible to measure inclination at any angle.

FIG. 9 shows an eighth sensor structure according to the present invention.
Is shown, which is a modification of the seventh embodiment, in which not only the working fluid but also other fluids that are immiscible with it are enclosed together in a sealed container, Since the other structure is the same as that of the seventh embodiment, the same parts will be described below by using the same reference numerals.

This sensor structure is a container 42 which is a non-magnetic case filled with the working fluid 1 and another fluid 41 which does not mix with the working fluid 1 and has a larger specific gravity than the working fluid 1, and the container 42. A chair-type base 45 in which four of the legs 45b, 45c, 45d, 45e extending from the base 45a are embedded in the working fluid 1, and the base 45a is wound around the base 45a. The secondary windings 43a and 43b and the primary windings 43c that intersect the primary windings 43a and 43b,
43d and each of the four legs 45b, 45c,
Secondary windings 44b, 44c, 4 wound around 45d, 45e
4d and 44e.

The primary windings 43a, 43b, 4 and
An alternating current flows through 3c and 43d,
Measuring devices for measuring electromotive force are connected to the secondary windings 44b, 44c, 44d and 44e.

Further, since the working fluid 1 is filled in the container 42 together with the other fluid 41 having a large specific gravity, the working fluid 1 is positioned above the other fluid 41.

Next, the operation of the sensor structure configured as described above will be described below. First, when an alternating current is passed through the primary windings 43a, 43b, 43c, 43d,
A magnetic flux is generated in the primary windings 43a, 43b, 43c, 43d, and due to this magnetic flux, the secondary windings 44b, 44c, 4
Induced electromotive force is generated in 4d and 44e.

The four legs 45b, 45c, 45
secondary windings 44b and 44 wound around d and 45e, respectively
The change in the liquid level of the working fluid 1 can be measured by detecting the differential potential of the induced electromotive force generated in c, 44d, and 44e.

Therefore, for example, when the container 42 is tilted, the liquid level changes, and the tilt of the container 42 can be measured by detecting the change in the liquid level.

The working fluid 1 is a dispersion medium in which surfactant-adsorbed magnetic fine particles are dispersed.
Since it is well separated from the working fluid 1 and the working fluid 1 does not adhere to the inner wall of the container 42, the responsiveness and reproducibility are improved, and the measurement accuracy as a sensor is improved.

Further, in this embodiment, the leg portion 45
secondary winding 44 on each of b, 45c, 45d, and 45e.
Since b, 44c, 44d, and 44e are wound, it is possible to measure inclination at any angle.

[0076]

As described above, according to the present invention, when the working fluid filled in the non-magnetic case moves, a voltage is generated. By measuring this voltage, the cause of the movement of the working fluid is caused. It is possible to detect pressure, inclination, acceleration, etc. In addition, since this working fluid is a dispersion medium in which the surfactant-adsorbed magnetic fine particles are dispersed, it has an excellent effect that it is difficult to adhere to the inner wall of the case and that the sensor has good responsiveness and reproducibility. ..

[Brief description of drawings]

FIG. 1 is a manufacturing process diagram showing a method for manufacturing a working fluid according to the present invention.

FIG. 2 is a schematic sectional view showing a first embodiment of the sensor structure according to the present invention.

FIG. 3 is a schematic sectional view showing a second embodiment of the sensor structure according to the present invention.

FIG. 4 is a schematic sectional view showing a third embodiment of the sensor structure according to the present invention.

FIG. 5 is a schematic sectional view showing a fourth embodiment of the sensor structure according to the present invention.

FIG. 6 is a schematic sectional view showing a fifth embodiment of the sensor structure according to the present invention.

FIG. 7 is a schematic sectional view showing a sixth embodiment of the sensor structure according to the present invention.

FIG. 8 is a schematic sectional view showing a seventh embodiment of the sensor structure according to the present invention.

FIG. 9 is a schematic sectional view showing an eighth embodiment of the sensor structure according to the present invention.

FIG. 10 is a schematic sectional view showing a conventional sensor structure.

[Explanation of symbols]

1 ... Working fluid 2,52 ... Communication pipe (case) 2a, 2b, 52a, 52b ... Legs 3a, 3b, 13, 23, 43a, 43b, 43c, 4
3d, 53a, 53b ... Primary winding 4a, 4b, 14a, 14b, 24a, 24b, 44
b, 44c, 44d, 44e, 54a, 54b ... Secondary winding 5a, 5b, 55a, 55b ... Opening 11, 21, 31, 41 ... Other fluid 22, 32 ... Sealed container (case) 33 ... Winding 33a ... 1st winding 33b ... 2nd winding 42 ... Container (case) 45 ... Base 45a ... Stand 45b, 45c, 45d, 45e ... Leg 51 ...... Magnetic fluid

Claims (7)

[Claims] 1. A working fluid (1) in which a surfactant-adsorbed magnetic microparticle is dispersed in a dispersion medium, wherein the surfactant-adsorbed magnetic microparticle contains an oily substance containing fine particles of a magnetic substance. A working fluid characterized in that an appropriate surfactant is adsorbed around the microcapsules. 2. A non-magnetic case (2) (22) filled with the working fluid (1) and a case (2) (22) located near the standard liquid surface of the working fluid (1). ) Primary windings (3a, 3b) (23) and 2
Secondary windings (4a, 4b) (24a, 24b), an AC power source for applying an alternating current to the primary windings (3a, 3b) (23), and the secondary windings (4a, 4b) (24a) , 24
b) and a measuring device connected to the primary winding (3
a, 3b) (23) is applied with an alternating current to measure the electromotive force generated in the secondary windings (4a, 4b) (24a, 24b) to detect the movement of the working fluid (1). Sensor structure characterized by. 3. A non-magnetic case (2) (22) filled with the working fluid (1) and another fluid (11) (21) that does not mix with the working fluid (1) and has a different specific gravity. ) And a primary winding (13) (23) and a secondary winding (which are located near the reference liquid level of the working fluid (1) and wound around the outer circumference of the case (2) (22) ( 14
a, 14b) (24a, 24b) and the primary winding (1
3) An alternating current power source for applying an alternating current to (23), and the above 2
The secondary winding (14a, 14b), which comprises a measuring device connected to the secondary winding (14a, 14b) (24a, 24b) and applies an alternating current to the primary winding (13) (23).
A sensor structure characterized by measuring the electromotive force generated in (24a, 24b) to detect the movement of the working fluid (1). 4. A horizontal non-magnetic case (32) filled with the working fluid (1), and a first winding (33a) and a second winding wound around the outer circumference of the case (32). A winding circuit (33b) and a first winding (33a) and a second winding (33b) to form a bridge circuit, and an alternating current power source for applying an alternating current to the bridge circuit. A sensor structure characterized by measuring the voltage generated in a circuit to detect the movement of the working fluid (1). 5. A horizontal non-magnetic case (3) filled with the working fluid (1) and another fluid (31) which does not mix with the working fluid (1) and has a different specific gravity.
2), a first winding wire (33a) and a second winding wire (33b) wound around the outer circumference of the case (32), and the first winding wire (33a).
A winding circuit (33a) and a second winding (33b) of the bridge circuit, and an alternating current power supply for applying an alternating current to the bridge circuit. The voltage generated in the bridge circuit is measured to perform the operation. A sensor structure characterized by detecting movement of a fluid (1). 6. A non-magnetic case (42) filled with the working fluid (1), and a part of legs (45b, 45c, 45d, 45e) inside the case (42) is the working fluid. A base (45) mounted in the state of being immersed in (1)
And 1 wound around the base (45a) of the base (45)
Subsequent windings (43a, 43b, 43c, 43d) and legs (45b, 45c, 45d, 45e) of the base (45)
Secondary windings (44b, 44c, 44d, 44)
e) and the primary windings (43a, 43b, 43c, 43)
d) consisting of an AC power supply for applying an AC current and a measuring device connected to the secondary windings (44b, 44c, 44d, 44e), and the primary windings (43a, 43b, 43c,
43d) by applying an alternating current to the secondary winding (44b,
44c, 44d, 44e) to measure the electromotive force generated to detect the movement of the working fluid (1). 7. A non-magnetic case (42) filled with the working fluid (1) and another fluid (41) that does not mix with the working fluid (1) and has a different specific gravity,
The legs (45b, 45c, 45) are provided inside the case (42).
(d, 45e) a base (45) which is placed with part of the working fluid (1) and the other fluid (41) immersed therein
And 1 wound around the base (45a) of the base (45)
Subsequent windings (43a, 43b, 43c, 43d) and legs (45b, 45c, 45d, 45e) of the base (45)
Secondary windings (44b, 44c, 44d, 44)
e) and the primary windings (43a, 43b, 43c, 43)
d) consisting of an AC power supply for applying an AC current and a measuring device connected to the secondary windings (44b, 44c, 44d, 44e), and the primary windings (43a, 43b, 43c,
43d) by applying an alternating current to the secondary winding (44b,
44c, 44d, 44e) to measure the electromotive force generated in the working fluid (1) to detect the movement.