JP6782098B2 - Fluid identification device - Google Patents

Description

The present invention relates to a fluid identification device.

A technique for detecting the state of a fluid has been proposed (see, for example, Patent Document 1).

Patent Document 1 discloses an oil deterioration detecting device for determining deterioration of oil that is circulated and supplied to a rotating portion and a sliding portion to prevent wear of each of these parts and operate smoothly. This oil deterioration detection device includes two plates installed in parallel with each other in the oil flow path, and by applying an AC voltage between these two plates, the conductivity and dielectric constant of the oil. Is determined, and the deterioration of the oil is judged based on the conductivity and the dielectric constant.

JP-A-2009-2693

The electrical features of a fluid, such as permittivity and conductivity, vary depending on the degree of deterioration of the fluid, but also on the type, manufacturer, brand, etc. of the fluid. However, in the oil deterioration detection device shown in Patent Document 1, the relationship between the type, manufacturer, and brand of the fluid and the electrical feature amount of the fluid is not considered. Therefore, the oil deterioration detection device shown in Patent Document 1 cannot identify the fluid, and if the type, manufacturer, and brand of the fluid are not known in advance, the electrical feature amount of the fluid is obtained. However, it was not possible to properly judge the deterioration of the fluid.

Therefore, the present invention has been made in view of the above-mentioned problems, and provides a fluid identification device for identifying a fluid.

One or more embodiments of the present invention is a fluid identification device for identifying a fluid, which controls the frequency of an AC voltage applied to the fluid to acquire the frequency characteristics of the electrical features of the fluid. The frequency characteristic acquisition unit, the storage unit that stores the frequency characteristics of the electrical characteristics of the fluid for each type of fluid, the frequency characteristics acquired by the frequency characteristic acquisition unit, and the storage unit are stored. The identification unit includes a frequency characteristic and an identification unit that identifies the fluid whose frequency characteristic has been acquired by the frequency characteristic acquisition unit, and the identification unit has an inclination of a curve representing the frequency characteristic of the electrical feature amount of the fluid. And, at least one of the frequency of the AC voltage and the electrical feature amount of the fluid when the absolute value of the change amount of the slope of the curve becomes equal to or higher than the threshold value is acquired by the frequency characteristic acquisition unit. It is characterized in that the fluid is identified by comparing with the frequency characteristic stored in the storage unit and the frequency characteristic stored in the storage unit.

According to one or more embodiments of the present invention, fluids can be identified.

It is a block diagram of the fluid identification apparatus which concerns on 1st Embodiment of this invention. It is a schematic block diagram of the frequency characteristic acquisition part included in the fluid identification apparatus which concerns on 1st Embodiment of this invention. It is a graph which shows an example of the frequency characteristic of the dielectric constant of a lubricating oil. It is a flowchart of the fluid identification apparatus which concerns on 1st Embodiment of this invention. It is a block diagram of the fluid identification apparatus which concerns on 2nd Embodiment of this invention. It is a graph which shows an example of the frequency characteristic of the conductivity of a lubricating oil.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The components in the following embodiments can be replaced with existing components as appropriate, and various variations including combinations with other existing components are possible. Therefore, the description of the following embodiments does not limit the content of the invention described in the claims.

<First Embodiment>
FIG. 1 is a block diagram of the fluid identification device 1 according to the first embodiment of the present invention. The fluid identification device 1 includes a frequency characteristic acquisition unit 10, a storage unit 20, and an identification unit 30, and identifies the lubricating oil in the device.

The frequency characteristic acquisition unit 10 controls the frequency of the AC voltage applied to the lubricating oil in the device to acquire the frequency characteristic of the dielectric constant of the lubricating oil. The storage unit 20 stores the frequency characteristics of the dielectric constant of the lubricating oil for each lubricating oil. The identification unit 30 identifies the lubricating oil whose frequency characteristics have been acquired by the frequency characteristic acquisition unit 10 based on the frequency characteristics acquired by the frequency characteristic acquisition unit 10 and the frequency characteristics stored in the storage unit 20. To do.

FIG. 2 is a schematic configuration diagram of the frequency characteristic acquisition unit 10. The frequency characteristic acquisition unit 10 includes a columnar base portion 11, a pair of electrodes 12 and 13 erected on the base portion 11, a power supply unit 14, and an acquisition unit 15.

The electrodes 12 and 13 are flat plate-shaped plates and are arranged in parallel with each other. The power supply unit 14 applies an AC voltage between the electrodes 12 and 13 installed in the lubricating oil, and controls the frequency of the AC voltage within a predetermined frequency range. The predetermined frequency range is appropriately set according to, for example, the frequency characteristic of the dielectric constant of the lubricating oil that may be put into the equipment, and is set, for example, in the range of 1 kHz to 100 MHz.

The acquisition unit 15 obtains the dielectric constant of the lubricating oil between the electrodes 12 and 13 in a state where the AC voltage whose frequency is controlled by the power supply unit 14 is applied to the electrodes 12 and 13, so that the lubricating oil can be used. Acquires the frequency characteristics of the permittivity.

The acquisition unit 15 has three frequency characteristics of the dielectric constant of the lubricating oil: the first frequency f1, the dielectric constant ε1 at the first frequency f1, and the slope Δε2 of the curve at the second frequency f2. Get the parameters. These three parameters will be described below with reference to FIG.

FIG. 3 is a graph showing an example of the frequency characteristics of the dielectric constant of the lubricating oil. The frequency characteristics of the dielectric constant of the lubricating oil differ depending on the type of lubricating oil (specifically, product name, product number, grade, etc.), manufacturer, brand, and the like. In particular, the values of the three parameters of the first frequency f1, the dielectric constant ε1 at the first frequency f1, and the slope Δε2 of the curve at the second frequency f2 are the types of lubricating oil, the manufacturer, the brand, and the like. It varies greatly depending on. Therefore, in the present embodiment, the frequency characteristic acquisition unit 10 acquires the three parameters of the first frequency f1, the dielectric constant ε1 at the first frequency f1, and the slope Δε2 of the curve at the second frequency f2. The frequency characteristic obtained is compared with the frequency characteristic stored in the storage unit 20, and the lubricating oil whose frequency characteristic has been acquired by the frequency characteristic acquisition unit 10 is identified.

First, the first frequency f1 will be described below.
When the frequency of the AC voltage applied between the electrodes 12 and 13 is increased from the lower limit frequency fmin, the slope of the curve representing the frequency characteristic of the dielectric constant of the lubricating oil gradually becomes smaller. The first frequency f1 is the frequency of the AC voltage when the slope of the curve representing the frequency characteristic of the dielectric constant of the lubricating oil becomes less than the threshold value.

Next, the dielectric constant ε1 at the first frequency f1 will be described below.
The dielectric constant ε1 at the first frequency f1 is the dielectric constant of the lubricating oil at the first frequency f1.

Next, the slope Δε2 of the curve at the second frequency f2 will be described below.
When the frequency of the AC voltage applied between the electrodes 12 and 13 is further increased from the first frequency f1, the curve representing the frequency characteristic of the dielectric constant of the lubricating oil reaches an inflection point. Assuming that the frequency of the AC voltage applied between the electrodes 12 and 13 at the turning point of the curve representing the frequency characteristic of the dielectric constant of the lubricating oil is the second frequency f2, the slope of the curve Δε2 at the second frequency f2 Is the slope of the curve representing the frequency characteristic of the dielectric constant of the lubricating oil at the second frequency f2.

The storage unit 20 stores in advance the frequency characteristics of the dielectric constant of the lubricating oil for each lubricating oil that may be charged into the device. Further, the details will be described later with reference to FIG. 4, but in the storage unit 20, when the similarity between the frequency characteristics acquired by the frequency characteristic acquisition unit 10 and the frequency characteristics stored in advance is less than a predetermined value. That is, when the frequency characteristic similar to or the same as the frequency characteristic acquired by the frequency characteristic acquisition unit 10 is not stored, the frequency characteristic acquired by the frequency characteristic acquisition unit 10 is input from the user in the device. Newly memorize in association with information about lubricating oil.

The frequency characteristic acquisition unit 10, the storage unit 20, and the identification unit 30 are realized by using a CPU, a memory (RAM), a hard disk, and the like.

The hard disk stores an operating system, a program for executing a series of processes for identifying a lubricating oil, and the like. The hard disk may be a non-temporary recording medium, and may be, for example, a non-volatile memory such as an EPROM or a flash memory, or a CD-ROM.

The CPU appropriately uses the memory to appropriately read the data and programs stored in the hard disk, and appropriately performs calculations and executions.

FIG. 4 is a flowchart of the fluid identification device 1.
In step S1, the fluid identification device 1 controls the frequency of the AC voltage applied to the lubricating oil in the device by the frequency characteristic acquisition unit 10, acquires the frequency characteristic of the dielectric constant of the lubricating oil, and processes it in step S2. To transfer.
As time passes after the lubricating oil is put into the equipment, the state of the lubricating oil changes due to oxidation of the lubricating oil or contamination of foreign matter, and the dielectric constant of the lubricating oil also changes. Therefore, the fluid identification device 1 performs the process of step S1 during the period from when the lubricating oil is charged into the device until a predetermined time elapses.

In step S2, the fluid identification device 1 calculates the similarity between the frequency characteristics acquired in step S1 and the frequency characteristics stored in the storage unit 20 by the identification unit 30, and processes in step S3. Move.

The calculation of the degree of similarity in step S2 will be described in detail below.
For example, a case of calculating the similarity between the frequency characteristic acquired in step S1 and the frequency characteristic of the lubricating oil A stored in the storage unit 20 will be described. In this case, first, the similarity between each of the above-mentioned three parameter values acquired in step S1 and each of the above-mentioned three parameter values for the lubricating oil A stored in the storage unit 20 is obtained. .. Next, the average value of the obtained three similarities is calculated as the similarity between the frequency characteristic acquired in step S1 and the frequency characteristic of the lubricating oil A stored in the storage unit 20.

In step S3, the fluid identification device 1 determines whether or not the highest degree of similarity calculated in step S2 is less than a predetermined value by the identification unit 30. When the fluid identification device 1 determines that the value is less than a predetermined value by the identification unit 30, that is, when the frequency characteristic similar to or the same as the frequency characteristic acquired in step S1 is not stored in the storage unit 20, the step The process is transferred to S4. On the other hand, when it is determined that the value is equal to or higher than the predetermined value, that is, when the frequency characteristic similar to or the same as the frequency characteristic acquired in step S1 is stored in the storage unit 20, the process is transferred to step S5.

In step S4, the fluid identification device 1 stores the frequency characteristics acquired in step S1 in the storage unit 20 by the identification unit 30, and ends the process shown in FIG.
After the process of step S4, the fluid identification device 1 receives the input of the type, manufacturer, and brand of the lubricating oil in the device from the user, and lubricates the frequency characteristics stored in the storage unit 20 in step S4. Associate oil types, manufacturers, and brands.

In step S5, the fluid identification device 1 supplies the lubricating oil having the frequency characteristic when the highest similarity is calculated in step S2 among the frequency characteristics stored in the storage unit 20 by the identification unit 30. Is identified as the lubricating oil of, and the process shown in FIG. 4 is completed.

As described above, in the fluid identification device 1, the frequency characteristic acquisition unit 10 acquires the frequency characteristic of the dielectric constant of the lubricating oil, and the identification unit 30 acquires the frequency characteristic acquired by the frequency characteristic acquisition unit 10 and the storage unit. The lubricating oil is identified based on the frequency characteristics of each lubricating oil stored by 20 and. Therefore, the lubricating oil in the equipment can be identified by using the frequency characteristic of the dielectric constant of the lubricating oil.

Further, the fluid identification device 1 has three frequency characteristics of the dielectric constant of the lubricating oil, that is, the first frequency f1, the dielectric constant ε1 at the first frequency f1, and the slope Δε2 of the curve at the second frequency f2. Use one parameter. Therefore, since the lubricating oil can be identified using parameters that differ greatly depending on the type, manufacturer, and brand of the lubricating oil, the lubricating oil in the equipment can be appropriately identified.

Further, the fluid identification device 1 calculates the similarity between the frequency characteristic acquired by the frequency characteristic acquisition unit 10 and the frequency characteristic stored in the storage unit 20 by the identification unit 30, and has the highest similarity. If is less than a predetermined value, the storage unit 20 stores the frequency characteristics acquired by the frequency characteristic acquisition unit 10. Therefore, when the frequency characteristic similar to or the same as the frequency characteristic acquired by the frequency characteristic acquisition unit 10 is not stored in the storage unit 20, this frequency characteristic is newly stored in the storage unit 20. Therefore, for the lubricating oil whose frequency characteristics are newly stored in the storage unit 20, the input of the type, manufacturer, and brand is accepted, and the received information is associated with the frequency characteristics newly stored in the storage unit 20. As a result, the amount of lubricating oil that can be identified by the fluid identification device 1 can be increased.

Further, as time elapses after the lubricating oil is put into the equipment, the state of the lubricating oil changes due to oxidation of the lubricating oil or contamination of foreign matter, and the dielectric constant of the lubricating oil also changes.
Therefore, the fluid identification device 1 acquires the frequency characteristic of the dielectric constant of the lubricating oil by the frequency characteristic acquisition unit 10 during the period from when the lubricating oil is charged into the apparatus until a predetermined time elapses. Therefore, it is possible to suppress the influence of the acquired lubricating oil on the frequency characteristic of the dielectric constant with the passage of time, and it is possible to appropriately identify the lubricating oil in the equipment.

In the present embodiment, there are three frequency characteristics of the dielectric constant of the lubricating oil: the first frequency f1, the dielectric constant ε1 at the first frequency f1, and the slope Δε2 of the curve at the second frequency f2. Parameters were used. However, the present invention is not limited to this, and at least one of these three parameters may be used.

Further, in the present embodiment, the frequency of the AC voltage applied between the electrodes 12 and 13 is increased from the lower limit frequency fmin to obtain the above-mentioned three parameters. However, the present invention is not limited to this, and the frequency of the AC voltage applied between the electrodes 12 and 13 may be lowered from the upper limit frequency fmax to obtain the above-mentioned three parameters.

Further, in the present embodiment, the frequency of the AC voltage applied between the electrodes 12 and 13 is increased from the first frequency f1, and the AC voltage at the turning point of the curve representing the frequency characteristic of the dielectric constant of the lubricating oil is increased. The frequency was set to the second frequency f2, and the slope Δε2 of the curve at the second frequency f2 was used as one of the above three parameters. However, not limited to this, the fifth frequency f5 is obtained in FIG. 3, and the slope of the above-mentioned curve between the first frequency f1 and the fifth frequency f5 is set to the slope Δε2 of the curve at the second frequency f2. It may be used instead.
When the frequency of the AC voltage applied between the electrodes 12 and 13 is increased from the first frequency f1, the curve representing the frequency characteristic of the dielectric constant of the lubricating oil reaches an inflection point, and then this curve is reached. The inclination of is gradually increasing. The fifth frequency f5 is the frequency of the AC voltage when the slope of the curve representing the frequency characteristic of the dielectric constant of the lubricating oil becomes equal to or greater than the threshold value.

Further, in the present embodiment, the frequency of the AC voltage applied between the electrodes 12 and 13 of the first frequency f1 is increased from the lower limit frequency fmin, and the slope of the curve representing the frequency characteristic of the dielectric constant of the lubricating oil is increased. Was the frequency of the AC voltage when was less than the threshold. However, not limited to this, the frequency of the AC voltage applied between the electrodes 12 and 13 of the first frequency f1 is increased from the lower limit frequency fmin, and the dielectric constant is determined with respect to the dielectric constant at the lower limit frequency fmin. It may be the frequency of the AC voltage when it is reduced by the ratio of.

Further, in the present embodiment, the lubricating oil in the device is identified, but the present invention is not limited to this, and any fluid can be identified.

Further, in the present embodiment, the electrodes 12 and 13 are formed from a flat plate, and the electrodes 12 and 13 are arranged in parallel with each other. However, the present invention is not limited to this, and the electrodes 12 and 13 may be formed from, for example, a cylindrical or elliptical columnar electrode plate. Further, electrodes 12 and 13 are formed of two cylindrical plates having different inner diameters, such as a coaxial cylindrical capacitor, and one of the electrodes 12 and 13 is used in a state where the central axes of the electrodes are aligned. It may be placed inside the other.

Further, in the present embodiment, the frequency characteristic of the dielectric constant of the lubricating oil is used. However, the present invention is not limited to this, and the frequency characteristic of the conductivity of the lubricating oil may be used, the electrical feature amount of the lubricating oil which is neither the dielectric constant nor the conductivity may be used, or this electrical feature amount may also be used.

<Second Embodiment>
FIG. 5 is a block diagram of the fluid identification device 1A according to the second embodiment of the present invention. The fluid identification device 1 according to the first embodiment of the present invention shown in FIG. 1 identifies the lubricating oil in the apparatus by using the frequency characteristic of the dielectric constant of the lubricating oil, whereas the fluid according to the present embodiment. The identification device 1A identifies the lubricating oil in the device by using the frequency characteristic of the conductivity of the lubricating oil. The fluid identification device 1A includes a frequency characteristic acquisition unit 10A, a storage unit 20A, and an identification unit 30A. The parts having the same shape as that of the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

The frequency characteristic acquisition unit 10A controls the frequency of the AC voltage applied to the lubricating oil in the device to acquire the frequency characteristic of the conductivity of the lubricating oil. The storage unit 20A stores the frequency characteristics of the conductivity of the lubricating oil for each lubricating oil. The identification unit 30A identifies the lubricating oil whose frequency characteristics have been acquired by the frequency characteristic acquisition unit 10A based on the frequency characteristics acquired by the frequency characteristic acquisition unit 10A and the frequency characteristics stored in the storage unit 20A. To do.

The frequency characteristic acquisition unit 10A is different from the frequency characteristic acquisition unit 10 according to the first embodiment of the present invention shown in FIG. 2 in that the acquisition unit 15A is provided instead of the acquisition unit 15. The acquisition unit 15A sets three parameters as the frequency characteristics of the conductivity of the lubricating oil: the third frequency f3, the conductivity σ3 at the third frequency f3, and the slope Δσ4 of the curve at the fourth frequency f4. get. These three parameters will be described below with reference to FIG.

FIG. 6 is a graph showing an example of the frequency characteristics of the conductivity of the lubricating oil. The frequency characteristics of the conductivity of the lubricating oil differ depending on the type, manufacturer, brand, etc. of the lubricating oil. In particular, the values of the three parameters of the third frequency f3, the conductivity σ3 at the third frequency f3, and the slope Δσ4 of the curve at the fourth frequency f4 are the type of lubricating oil, the manufacturer, the brand, and the like. It varies greatly depending on. Therefore, in the present embodiment, the frequency characteristic acquisition unit 10A acquires the three parameters of the third frequency f3, the conductivity σ3 at the third frequency f3, and the slope Δσ4 of the curve at the fourth frequency f4. The frequency characteristic obtained is compared with the frequency characteristic stored in the storage unit 20A to identify the lubricating oil whose frequency characteristic has been acquired by the frequency characteristic acquisition unit 10A.

First, the third frequency f3 will be described below.
When the frequency of the AC voltage applied between the electrodes 12 and 13 is increased from the lower limit frequency fmin, the slope of the curve representing the frequency characteristic of the conductivity of the lubricating oil gradually increases. The third frequency f3 is the frequency of the AC voltage when the slope of the curve representing the frequency characteristic of the conductivity of the lubricating oil becomes equal to or higher than the threshold value.

Next, the conductivity σ3 at the third frequency f3 will be described below.
The conductivity σ3 at the third frequency f3 is the conductivity of the lubricating oil at the third frequency f3.

Next, the slope Δσ4 of the curve at the fourth frequency f4 will be described below.
When the frequency of the AC voltage applied between the electrodes 12 and 13 is further increased from the third frequency f3, the curve representing the frequency characteristic of the conductivity of the lubricating oil reaches an inflection point. Assuming that the frequency of the AC voltage applied between the electrodes 12 and 13 at the turning point of the curve representing the frequency characteristic of the conductivity of the lubricating oil is the fourth frequency f4, the slope of the curve Δσ4 at the fourth frequency f4 Is the slope at the fourth frequency f4 of the curve representing the frequency characteristic of the conductivity of the lubricating oil.

The frequency characteristic acquisition unit 10A, the storage unit 20A, and the identification unit 30A are realized by using a CPU, a memory (RAM), a hard disk, or the like, similarly to the frequency characteristic acquisition unit 10, the storage unit 20, and the identification unit 30. To.

The above fluid identification device 1A can exert the same effect as the fluid identification device 1 according to the first embodiment of the present invention.

In the present embodiment, there are three frequency characteristics of the conductivity of the lubricating oil: the third frequency f3, the conductivity σ3 at the third frequency f3, and the slope Δσ4 of the curve at the fourth frequency f4. Parameters were used. However, the present invention is not limited to this, and at least one of these three parameters may be used.

Further, in the present embodiment, the frequency of the AC voltage applied between the electrodes 12 and 13 is increased from the lower limit frequency fmin to obtain the above-mentioned three parameters. However, the present invention is not limited to this, and the frequency of the AC voltage applied between the electrodes 12 and 13 may be lowered from the upper limit frequency fmax to obtain the above-mentioned three parameters.

Further, in the present embodiment, the frequency of the AC voltage applied between the electrodes 12 and 13 is increased from the third frequency f3, and the AC voltage at the turning point of the curve representing the frequency characteristic of the conductivity of the lubricating oil is increased. The frequency was set to the fourth frequency f4, and the slope Δσ4 of the curve at the fourth frequency f4 was used as one of the above three parameters. However, not limited to this, the sixth frequency f6 is obtained in FIG. 6, and the slope of the above-mentioned curve between the third frequency f3 and the sixth frequency f6 is set to the slope Δσ4 of the curve at the fourth frequency f4. It may be used instead.
When the frequency of the AC voltage applied between the electrodes 12 and 13 is increased from the third frequency f3, the curve representing the frequency characteristic of the conductivity of the lubricating oil reaches the inflection point, and then this curve. The inclination of is gradually reduced. The sixth frequency f6 is the frequency of the AC voltage when the slope of the curve representing the frequency characteristic of the conductivity of the lubricating oil becomes less than the threshold value.

Further, in the present embodiment, the frequency of the AC voltage applied between the electrodes 12 and 13 of the third frequency f3 is increased from the lower limit frequency fmin, and the slope of the curve representing the frequency characteristic of the conductivity of the lubricating oil is increased. Was used as the frequency of the AC voltage when was equal to or higher than the threshold value. However, not limited to this, the frequency of the AC voltage applied between the electrodes 12 and 13 of the third frequency f3 is increased from the lower limit frequency fmin, and the conductivity is determined with respect to the conductivity at the lower limit frequency fmin. It may be the frequency of the AC voltage when it is increased by the ratio of.

Further, in the present embodiment, the lubricating oil in the device is identified, but the present invention is not limited to this, and any fluid can be identified.

Further, in the present embodiment, the electrodes 12 and 13 are formed from a flat plate, and the electrodes 12 and 13 are arranged in parallel with each other. However, the present invention is not limited to this, and the electrodes 12 and 13 may be formed from, for example, a cylindrical or elliptical columnar electrode plate. Further, electrodes 12 and 13 are formed of two cylindrical plates having different inner diameters, for example, a coaxial cylindrical capacitor, and one of the electrodes 12 and 13 is used in a state where the central axes of the electrodes are aligned. It may be placed inside the other.

Further, in the present embodiment, the frequency characteristic of the conductivity of the lubricating oil is used. However, the present invention is not limited to this, and the frequency characteristic of the dielectric constant of the lubricating oil may be used, the electrical feature amount of the lubricating oil which is neither the dielectric constant nor the conductivity may be used, or this electrical feature amount may also be used.

Although the embodiments of the present invention have been described in detail with reference to the drawings, the specific configuration is not limited to the above-described embodiments, and includes designs within a range that does not deviate from the gist of the present invention. ..

The present invention can also be applied to, for example, hydraulic equipment.

1,1A Fluid identification device 10, 10A Frequency characteristic acquisition unit 11 Base 12, 13 Electrode 14 Power supply unit 15, 15A Acquisition unit 20, 20A Storage unit 30, 30A Identification unit

Claims (4)

A fluid identification device that identifies fluids
A frequency characteristic acquisition unit that controls the frequency of the AC voltage applied to the fluid and acquires the frequency characteristics of the electrical features of the fluid.
A storage unit that stores the frequency characteristics of the electrical features of the fluid for each type of fluid,
A frequency characteristic obtained by the frequency characteristic acquisition unit, and the frequency characteristic stored in the storage block, by comparing the identification unit identifies the fluid frequency characteristic obtained by the frequency characteristic acquisition unit, With
The frequency characteristic acquisition unit has the frequency characteristic as the frequency characteristic.
The frequency of the AC voltage and the electrical characteristics of the fluid when the frequency of the AC voltage is changed from a predetermined frequency and the slope of the curve representing the frequency characteristics of the electrical features of the fluid becomes less than the threshold value. Amount and
A fluid identification device characterized in that the frequency of the AC voltage is further changed after the slope of the curve becomes less than the threshold value, and the slope of the curve when the curve reaches an inflection point is acquired. .. A fluid identification device that identifies fluids
A frequency characteristic acquisition unit that controls the frequency of the AC voltage applied to the fluid and acquires the frequency characteristics of the electrical features of the fluid.
A storage unit that stores the frequency characteristics of the electrical features of the fluid for each type of fluid,
A frequency characteristic obtained by the frequency characteristic acquisition unit, and the frequency characteristic stored in the storage block, by comparing the identification unit identifies the fluid frequency characteristic obtained by the frequency characteristic acquisition unit, With
The frequency characteristic acquisition unit has the frequency characteristic as the frequency characteristic.
The frequency of the AC voltage and the electrical characteristics of the fluid when the frequency of the AC voltage is changed from a predetermined frequency and the slope of the curve representing the frequency characteristics of the electrical features of the fluid becomes equal to or greater than the threshold value. Amount and
A fluid identification device characterized in that the frequency of the AC voltage is further changed after the slope of the curve becomes equal to or higher than the threshold value, and the slope of the curve when the curve reaches an inflection point is acquired. .. The fluid identification according to any one of claims 1 or 2 , wherein at least one of the dielectric constant of the fluid and the conductivity of the fluid is used as the electrical feature amount of the fluid. apparatus. The identification unit determines whether or not the similarity between the frequency characteristics acquired by the frequency characteristic acquisition unit and the stored frequency characteristics is less than a predetermined value.
When the identification unit determines that the similarity is less than the predetermined value, the storage unit receives input of information about the fluid whose frequency characteristics have been acquired by the frequency characteristic acquisition unit, and receives the input of information about the fluid whose frequency characteristics have been acquired by the frequency characteristic acquisition unit. The fluid identification device according to any one of claims 1 to 3 , wherein the frequency characteristic acquired by the acquisition unit and the information that has received the input are stored in association with each other.

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