JP2001116611A - Apparatus for measuring liquid level in filled container and flow control type filling method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To rapidly and surely measure a liquid level for containers such as an opaque can as well as a transparent glass bottle, PET (polyethylene terephthalate) bottle, and the like. SOLUTION: A container 22 filled with a beverage is conveyed into a measuring box 20, and is fanned by a blower 26. Immediately after the container 22 is filled with the beverage, there is a significant temperature difference between liquid and gas sides. The heat distribution of the container 22 is relaxed during the movement on a conveyor 21 and the like, relaxing the temperature distribution of a gas-liquid interface. Then, by feeding the wind forcedly from outside to the container 22, the heat transfer in a surface of the container 22 is improved so as to rapidly change the surface temperature of the container 22. Accordingly, since the outside surface temperature of the container 22 to the gas-liquid interface is highlighted, an infrared radiation intensity radiated from the surface of the container 22 is photographed by an infrared camera 27 and is input into an image-processing device 28. A photographed image of the infrared camera 27 is processed by the image-processing device 28 to extract a noticeable tone portion as the gas-liquid interface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid filling height measuring device for measuring the filling height of a liquid filled in a container, for example, with a beverage filling machine or the like, and to a flow control type filling method.

[0002]

2. Description of the Related Art Conventionally, in a beverage filling machine, after filling a container with a fixed amount of beverage, it is checked in a final inspection step whether or not the container is properly filled with the beverage. Examples of the container include a glass bottle, a PET bottle, an aluminum can,
Iron cans, paper packs, aluminum packs and the like are used.

[0003] As a method of measuring the height of the beverage in the above-mentioned container, for a glass bottle or a PET bottle in which the content liquid is visible visually, visible light or near-infrared light is used, and the amount of transmitted light is attenuated by the beverage. There is used a method of measuring the height of a beverage utilizing the above, or a method of taking a liquid surface portion illuminated with visible light or near-infrared light with a camera and extracting a liquid interface by image processing.

[0004] Further, in the above-mentioned aluminum cans, iron cans, paper packs, aluminum packs and the like, since the content liquid is invisible, a method of confirming the presence or absence of beverages using X-rays or γ-rays, or using an X-ray camera A method of taking an image of a liquid surface portion and extracting a liquid interface in the container by image processing or the like is used.

A technique for measuring the amount of infrared radiation radiated from the outside of the container and extracting the liquid level is disclosed in, for example, Japanese Utility Model Application Laid-Open Publication No. Hei.
No. 109329 (liquid level detecting device in a container). FIG. 5 is a view showing the configuration of a main part of a liquid level detecting device in a container disclosed in the above-mentioned Japanese Utility Model Application Laid-Open No. 4-109329. As shown in FIG. 1, a liquid 2, for example, water, oil, and other chemicals are contained in a liquid container 1.
Is the liquid level. In this case, the temperature of the liquid 2 and the gas 6
, The outer surface of the container 1 has T1 and T2, respectively.
, Which emits infrared radiation according to Stefan-Boltzmann's law. This infrared light is captured by the infrared camera 3, processed by the infrared image processing device 4, and displayed on the display 5. Thereby, the temperature difference between T1 and T2 can be measured. The liquid level position is determined from the temperature boundary position between T1 and T2 at this time. At the time of the above measurement, the container 1 is forcibly heated by an infrared heater or the like, and a difference in temperature rise is measured due to a difference in heat capacity.

In general, a state in which a liquid is present in a container means that a liquid exists on the bottom side and a space exists on the upper side of the liquid.
The liquid has a larger heat capacity than the air in the space side, so that a change in ambient temperature causes a temperature difference between the gas part and the liquid part. Therefore, the liquid level position in the container can be detected from the temperature difference. Further, when heat energy is positively applied by an infrared heater or the like at the time of measurement as described above, a temperature difference due to a difference in heat capacity becomes remarkable, and the liquid level position in the container can be easily measured.

A similar technique is disclosed in Japanese Patent Application Laid-Open No. 9-333.
No. 20 discloses a device for detecting a liquid level in a container. FIG.
FIG. 2 is a configuration diagram of a liquid surface exploration device in the container. In FIG. 6, reference numeral 11 denotes a container, in which a gas 12 and a liquid 13 are stored, and a window 11b for observing the level L of the liquid 13 stored therein is provided on a side wall 11a thereof. Is formed. The main body of the container 11 is formed of an iron alloy or the like, and the window 11b is covered with a transparent member having a low thermal conductivity such as reinforced plastic and a high strength. Further, a heat source 14 for heating the side wall 11a of the container 11 is provided. Further, a heat shield plate 15 is provided between the side wall 11a of the container 11 and the heat source 14 as needed.
The heat shielding plate 15 is for thermally shielding the space between the heat source 14 and the side wall 11a of the container 11 after heating the side wall 11a of the container 11 to a desired temperature. Further, an infrared camera 16 for imaging the side wall 11a of the heated container 11 is provided. The image captured by the infrared camera 16 is sent to the image processing device 17 for processing.

In the above configuration, after the interior of the container 11 is heated to a desired temperature by the heat source 14 and the gas 12 and the liquid 13 in the container 11 rise to the desired temperature, the heat source 14 is shut off by the heat shield plate 15. . After that, the infrared camera 16 captures an image of the heated portion of the side wall 11a of the container 11 and inputs a thermal image indicating a heat radiation state to the image processing device 17. The image processing device 17 stores the thermal image captured by the infrared camera 16, visually determines the temperature distribution in the gas 12, the liquid 13, and the boundary region between the two, from the thermal image and determines the temperature distribution in the container 11. The liquid levels of the liquid 12 and the liquid 13 are determined.

As described above, the liquid 13 in the container 11 is
Of the window 11 can be determined in a non-contact manner.
Even if b is dirty, the liquid level can be determined as it is.

[0010]

SUMMARY OF THE INVENTION
The liquid level detecting device in the container disclosed in No. 329 forcibly heats the container 1 with an infrared heater or the like and measures a difference in temperature rise due to a difference in heat capacity. Although it is possible to easily measure, there is a problem that the heat of the heater directly hits the container 1 and is reflected on the surface of the container 1 to be reflected as a hot spot, or uneven heating of the heater is reflected to the infrared camera 3. .

Further, the liquid level detecting device in the container disclosed in Japanese Patent Application Laid-Open No. 9-33320 can determine the remaining amount of the liquid 13 in the container 11 in a non-contact manner, and can also determine the remaining amount of the liquid 13 in the container 11.
The liquid level can be determined as it is even if the container 11 is dirty.
Is heated to a desired temperature, and the gas 12 inside the container 11 is heated.
After the temperature of the liquid and the liquid 13 have risen to the desired temperature, the heat source 14 must be shut off by the heat shield plate 15.

[0012] In a beverage filling machine, detecting the filling height of the beverage is important in shipping inspection of the beverage product. In recent years, glass bottles that can be easily returned have been reviewed. However, the glass bottle has a problem that it is not possible to employ the fixed filling because the molding accuracy of the container is not good. The liquid filling height measuring device in the container using a normal infrared camera and image processing device is a glass bottle and PE
Although applied to T bottles, erroneous detection may occur due to printed characters in glass bottles, and aperture stripes in PET bottles to enhance label and strength. Further, X-rays and radiation are used in cans that are invisible inside, but the intensity of the radiation source is hardly adjusted during installation, and there is a risk of exposure. In addition, since the fluctuation of the liquid in the can is measured by the transmitted dose, the measurement error increases.

The present invention has been made to solve the above-mentioned problems, and is applicable not only to containers such as glass bottles and PET bottles whose inside can be visually observed, but also to containers such as cans, paper packs, and aluminum packs whose inside is invisible. It is an object of the present invention to provide an in-vessel liquid filling height measuring device capable of quickly and reliably measuring the liquid level, and a flow control type filling method capable of accurately filling the container with liquid.

[0014]

According to a first aspect of the present invention, there is provided an apparatus for measuring the filling height of a liquid in a container, comprising: conveying means for conveying a container filled with liquid; and blowing air to the container conveyed by the conveying means. A blower that emphasizes a surface temperature difference outside the container with respect to a gas-liquid interface in the container, and an infrared camera that captures infrared radiation energy radiated from the container surface,
Image processing means for processing an image photographed by the infrared camera and detecting a portion having a remarkable change in shading as a gas-liquid interface.

A second aspect of the present invention is a liquid filling height measuring device for a container, wherein the blower and the infrared camera are provided in a measuring box for measurement.

In the liquid filling height measuring apparatus according to a third aspect of the present invention, a rectifying device such as a rectifying grid or a punching metal is provided at an outlet of the blower, or air is blown in accordance with the shape of the container to hit the container. The method is characterized in that the measurement is performed while eliminating the unevenness of the surface wind speed and making the heat transfer conditions outside the container uniform.

According to a fourth aspect of the present invention, there is provided an apparatus for measuring a liquid filling height in a container, comprising: first mirrors disposed on both sides of the container conveyed by the conveying means; and the container reflected by the first mirror. A second mirror for guiding infrared radiation energy from the surface to the infrared camera is provided, and a gas-liquid interface is measured over the entire outer periphery of the container.

A flow control type filling method according to a fifth aspect of the present invention
Flow rate measuring means, transport means for transporting a container filled with liquid, and air blown to the container transported by the transport means, and gas-liquid A blower that emphasizes the surface temperature difference outside the container with respect to the interface, an infrared camera that captures infrared radiant energy emitted from the container surface, and an infrared camera that uses the infrared camera to transfer infrared radiation energy from the container surface transported by the transport unit An image processing means for processing a photographed image and detecting a portion having a remarkable change in density as a gas-liquid interface is provided with a liquid filling height measuring device in a container, and based on a measurement result of the liquid filling height measuring device in the container. And changing the set values of the flow meters attached to the respective fixed quantity filling sections.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a system configuration diagram showing the overall configuration of a liquid level measuring device according to the present invention. In FIG.
Reference numeral 20 denotes a measurement box whose inside is insulated, and a container 22 already filled with a liquid, for example, a beverage is placed in the measurement box 20 on the conveyor 2.
1 sequentially transported. The container 22 that has passed through the measurement box 20 is transported to the next process by the main transport conveyor 23, but defective products are rejected by the rejector 24 and sent to the defective product zone 25.

In the measuring box 20, a conveyor 2 is provided.
A blower 26 for sending air to the upper container 22 is provided, and an infrared camera 27 for photographing the container 22 is provided. The image taken by the infrared camera 27 is
It is sent to the image processing device 28. When the container 22 is photographed by the infrared camera 27, the inner surface plate of the measurement box 20 is used as a background plate 20a. Also, the background plate 20a
May be provided independently without using the inner surface plate of the measurement box 20. In addition, the measurement box 20 also has a role of removing intrusion of heat which becomes disturbance such as sunlight or illumination light.

The image processing device 28 is controlled by a control computer 29, and displays a processed image on the display device 3.
Output to 0 and display, and output to control computer 29. The control computer 29 determines whether or not the beverage is normally filled in the container 22 based on the processing result of the image processing device 28, and outputs a control command to the rejector 24 according to the determination result. That is, if the container 22 sent out from the measurement box 20 is a normal product, that is, if the container 22 is normally filled with the liquid, the control computer 29 does not operate the rejector 24 and moves the container 22 to the main conveyor 23. To the next process,
Is abnormal, that is, the container 22
If the liquid filling amount is abnormal, the rejector 2
4 is operated to evacuate the container 22 to the defective zone 25 by another conveyor line.

Next, the operation of the above embodiment will be described. The container 22 carried into the measuring box 20 is already filled with the beverage in the previous process, and as shown in FIG.
, And the upper part is gas 33. Note that FIG.
Is an infrared intensity image 3 output from the infrared camera 27.
1 is an image taken into the image processing device 28, that is, a grayscale image in which the infrared intensity is normalized by, for example, “0-255”.

Then, when the container 22 filled with the beverage is carried into the measuring box 20, the air is blown by the blower 26 and then photographed by the infrared camera 27.

In the container 22 immediately after the beverage is filled, there is a large temperature difference between the liquid 32 side and the gas 33 side.
While the container 2 is moving on the conveyor 21 or the like, the distribution of heat in the container 22 is relaxed, and the temperature distribution at the gas-liquid interface becomes gentle. Therefore,
By forcibly sending air from the outside to the beverage-filled container 22, heat transfer on the container surface can be improved, and the temperature on the container 22 surface can be rapidly changed. In this case, the gas 33 in the upper part of the container has a small amount of heat of the gas 33, and the heat transfer coefficient inside the container 22 is very small because there is no wind. Therefore, the liquid 32 portion of the container 22 has a larger calorific value than the gas 33 and also has a higher heat transfer coefficient with the container 22. For this reason, the container 2
The speed at which the temperature of the liquid 32 inside 2 approaches the wind temperature is lower than that of the upper gas 33 portion.

Thus, the surface temperature of the gas-liquid interface outside the container can be emphasized, so that the infrared radiation intensity radiated from the surface of the container 22 is measured by the infrared camera 27.
Since the measured infrared intensity multiplied by the emissivity of the container surface represents the container surface temperature, the infrared intensity is normalized in an arbitrary range, and the scale is set to, for example, "0-255". Thus, a low temperature location can be represented by “0” and a high temperature location can be represented by “255”. This scale can be input as a grayscale image to a grayscale image processing device normally used in a camera. The image processing unit 28 performs image processing on the portion where the shading change is remarkable and extracts it. Since the above-mentioned portion where the change in density is remarkable is a portion where the change in temperature is remarkable, the container 2
The image processing device 28, which can detect the portion of the surface where the temperature change is remarkable, that is, the gas-liquid interface, measures the position of the extracted gas-liquid interface on the image, determines the position as the liquid surface position, and determines the liquid level. If there is a defective container 22, control computer 2
A reject command is sent to a rejector 24 via 9 and the container 22 is guided to a defective zone 25.

Next, as a specific example, a case where an aluminum can filled with a carbonated beverage at 5 ° C. is used as the container 22 will be described.

In a can 22 made of aluminum filled with a carbonated beverage at 5 ° C., the gas temperature approaches the beverage temperature and the overall surface temperature approaches 5 ° C. while being transported by the conveyor 21. Air having the same temperature as the ambient temperature is blown to the container 22 by a blower 26. At this time, the blower 26
From the air blows slightly and blows on several containers 22 located in front of the blower 26. The spraying range depends on the conveyor speed, the material and thickness of the container, the temperature of the liquid 32 in the container 22, and the ambient temperature. The infrared radiation energy thermally radiated from the outer surface of the container 22 to which the air is blown is measured by the infrared camera 27. The image captured by the infrared camera 27 is a grayscale image normalized at a minimum temperature of 0 ° C. to a maximum temperature of 50 ° C. (infrared intensity of each pixel in the image is “0-2”).
55), the image is subjected to gray image processing by the image processing device 28. Since the liquid surface is in the horizontal direction with respect to the infrared intensity image 31, the liquid surface is differentiated in the vertical direction. Normally, since the infrared intensity image 31 contains fine noise, performing differential processing between five or seven pixels is more resistant to noise than differential processing between three pixels which is normally performed. Become. In addition, several pixels (3 to
Even after the smoothing process is performed in 7), the noise immunity can be improved.

A large portion (peak) of the temperature gradient emphasized in the above-described differential processing is extracted or binarized at a certain threshold value, that is, “0” when the temperature is below the threshold, and “25” when the value is above the threshold.
5 ". Then, the binarized image is subjected to histogram processing in the horizontal direction, and the most frequent portion is a portion with a high temperature gradient, that is, a gas-liquid interface. Further, when speeding up is necessary, while taking a moving average in the vertical direction of one pixel, a density change point detection for calculating the difference is performed to extract a gas-liquid interface.

Since the infrared camera 27 is fixed,
The position in the image of the extracted gas-liquid interface becomes the actual liquid level in the container. Therefore, it is determined whether or not the extracted position is equal to or greater than the determination value or within the determination range, and the display device 30 displays the measured infrared intensity image 31 and the determination result. As a result of this determination, if the product is non-defective, the container 22 passes through the rejector 24 and is
It is transported to the next process by 3. Also, as a result of the above determination,
If the product is defective, the rejector 24 uses the defective zone 2
Moved to 5.

By providing the blower 26 in the measurement box 20 and blowing air to the container 22 as described above, heat transfer on the surface of the container 22 is promoted, and the internal temperature information is transmitted to the outside of the container. As a result, the temperature of the gas 33 at the upper portion of the container approaches the temperature of the blown air, and the temperature of the liquid 32 at the lower portion of the container approaches the temperature of the liquid 32. In addition, since the temperature is enhanced by the blower 26, the container itself does not become a thermal disturbance, and the temperature can be enhanced with the outside of the container. For this reason, very high response (for example, 25 Hz (1500 can / min) or more)
And a high measurement accuracy of about ± 0.3 mm can be obtained. In the above embodiment, what is in the measurement environment includes the blower 26, the infrared camera 27, and the background plate 2.
0a (or the inner surface plate of the measurement box 20). The temperature of the air blown by the blower 26 is substantially the ambient temperature, and the infrared camera 27 and the background plate 20a are also at the same temperature as the ambient temperature. Therefore, the surface temperature of the container 22 can be correctly measured without giving an error factor when measuring the infrared radiation on the surface of the container 22.

Further, in order to increase the inspection efficiency, the temperature of the entire container 22 may be changed with hot air, cold air, cold water, or hot water in the preceding stage of the inspection device, and then the inspection may be performed by the inspection device shown in FIG. Further, for the purpose of improving the stability and the effect, the temperature in the measuring box 20 may be adjusted or the set temperature may be raised or lowered.
In this case, the same effect can be obtained even if the air is blown at a preset temperature.

Further, by using a plurality of blowers 26 and providing a rectifying device at each blower outlet, it is possible to reduce blow-off unevenness and to promote heat transfer outside the container 22. For example, by providing a rectifying device with a rectifying grid or punching metal at the outlet of the blower, or by performing blowing in accordance with the shape of the container, the unevenness of the surface wind velocity hitting the container is eliminated, and the heat transfer conditions outside the container are made uniform. Can be measured.

(Second Embodiment) Next, a second embodiment of the present invention will be described. FIG. 3 is a schematic configuration diagram of a liquid filling height measuring device in a container according to a second embodiment of the present invention. In the second embodiment, even when the liquid 32 filled in the container 22 fluctuates during transportation, the liquid level can be accurately measured. In the second embodiment, the mirror 41 is disposed obliquely on the upper part of the container 22 carried into the measurement box 20 and, for example, the mirrors 42a are positioned on both sides of the container 22 to be conveyed.
42b is arranged obliquely. And the mirror 41
The infrared camera 27 is arranged so as to be located on the side of the camera. That is, the infrared radiation radiated from the peripheral surface of the container 22 is reflected upward by the mirrors 42a and 42b,
The reflected infrared rays are further reflected by the mirror 41 and enter the infrared camera 27. FIG. 3 shows the arrangement relationship of the mirrors 41, 42a, 42b and the infrared camera 27, and omits the conveyor 21, the blower 26 and the like shown in FIG.

As described above, the mirrors 41, 42a, 42b
Is arranged and the entire circumference of the container 22 is measured, so that even when the liquid 32 filled in the container 22 fluctuates during transportation, the liquid level can be accurately measured. In addition, the same effects as in the first embodiment can be obtained.

In the above embodiment, the beverage is stored in the container 22.
Although the case of filling into the container 22 has been described, the present invention is not limited to beverages and can be implemented when filling the container 22 with other liquids.

(Third Embodiment) Next, a third embodiment of the present invention will be described with reference to FIG. This third embodiment shows a flow control type filling method in a rotary filling machine. FIG. 4 shows a part of a rotary filling machine 50.
A filling valve 52 for filling the container 22 with liquid, an electromagnetic flow meter (not shown) for measuring a flow rate of the liquid filled by each filling valve 52, and the like are provided. At the time of filling, the rotary filling machine 50 takes in the container 22 by the rotary turntable 51, and after replacing the gas in the container with CO ₂ , opens the filling valve 52 to start filling.

During the above filling, after counting the number of flow pulses output from the electromagnetic flow meter until it reaches a certain setting, the filling valve 52 is closed. Next, after the container surface temperature difference is emphasized by the blower 26, the infrared radiation energy radiated from the surface of the container 22 is measured by the infrared camera 27. Since the surface temperature is obtained by multiplying the infrared radiant energy from the container surface by the emissivity, when the container 22 of the same material is always measured as shown in the above-described embodiment, it is necessary to directly process the infrared radiant energy image. Is possible. This image is input to the image processing device 28, and after the liquid level is extracted, the liquid level is measured. The processing result of the image processing device 28 is displayed on the display device 30 and sent to the control computer 29. In the liquid level measurement unit using the infrared camera 27 or the like, a heat insulating plate 53 is provided on the back side of the container 22 transported by the rotary turntable 51.

The control computer 29 adjusts the filling amount of the liquid in the next container 22 based on the liquid level data obtained by the image processing device 28. In general, a container such as an aluminum can or a PET bottle having a high molding accuracy is equivalent to filling a liquid having a substantially constant volume if a predetermined height is filled. Therefore, if the liquid level data is higher than a certain reference height, the image processing device 28
A control command is output so as to reduce the number of output pulses from the electromagnetic flow meter by the amount corresponding to the internal volume, and to increase the count of output pulses from the electromagnetic flow meter if the number is small. In practice, an average value of about several bottles is used for this count number control, and the time constant of the setting is reduced to improve the accuracy. In the case of the above-mentioned rotary filling machine 50, the container 22 conveyed by the rotary turntable 51 has a long cycle from completion of filling to sending to the next step, during which time the liquid surface has little fluctuation and is stable. Since the state is maintained, the liquid level can be measured reliably.

[0040]

As described above in detail, according to the present invention, air is sprayed on a container filled with liquid, infrared radiation energy radiated from the surface of the container is measured, and the amount of infrared radiation energy is measured based on the magnitude of the infrared radiation energy. Since the liquid filling height in the container is measured, the temperature of the gas-liquid interface in the container can be emphasized, and not only containers such as glass bottles and PET bottles that allow the inside to be seen, but also cans, paper packs, The liquid level can be measured quickly and reliably even for aluminum packs and the like. In addition, by providing a rectifying device with a rectifying grid or punching metal at the outlet of the blower, or by blowing air in accordance with the shape of the container, the uneven wind speed that hits the container is eliminated, and the heat transfer conditions outside the container are made uniform. Can be measured. In addition, since a plurality of mirrors are arranged along the outer periphery of the container and the reflection can be used to measure the liquid level of the entire periphery of the container, the liquid filled in the container shakes during the transfer. Even in this case, the liquid level can be accurately measured.

Further, based on the liquid level height data measured by this measuring device corresponding to each filling valve, the integrated pulse for closing the filling valve is determined by the number of pulses from the flow meter attached to the filling valve. It is also possible to automatically correct the set value of the number.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of a liquid filling height measuring device in a container according to a first embodiment of the present invention.

FIG. 2 is a view showing an example of an infrared intensity image in the embodiment.

FIG. 3 is a configuration diagram showing a main part of a liquid filling height measuring device in a container according to a second embodiment of the present invention.

FIG. 4 is a configuration diagram showing a main part of a flow control type filling method according to a third embodiment of the present invention.

FIG. 5 is a configuration diagram showing a main part of a conventional liquid level detecting device in a container.

FIG. 6 is a configuration diagram of a conventional liquid level detecting device in a container.

[Explanation of symbols]

 Reference Signs List 20 Measurement box 21 Conveyor 22 Container 23 Main transport conveyor 24 Rejector 25 Defective zone 26 Blower 27 Infrared camera 28 Image processing device 29 Control computer 30 Display device 31 Infrared intensity image 32 Liquid 33 Gas 41, 41a, 41b Mirror 50 Rotary filling Machine 51 Rotary turntable 52 Filling valve

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2F014 CA10 3E018 AA02 AB06 BA07 BB02 DA02 DA05 EA02 3E079 AB01 AB02 FF01 FG07

Claims (5)

[Claims] 1. A conveying means for conveying a container filled with a liquid, and a blower for blowing air to the container conveyed by the conveying means to emphasize a surface temperature difference between the gas-liquid interface inside the container and the outside of the container. An infrared camera that captures infrared radiant energy emitted from the surface of the container, and image processing means that processes an image captured by the infrared camera and detects a portion having a remarkable change in density as a gas-liquid interface. Characteristic liquid filling height measuring device in a container. 2. The liquid filling height measuring apparatus according to claim 1, wherein the blower and the infrared camera are provided in a measuring box for measurement. 3. An apparatus for measuring the filling height of liquid in a container according to claim 1, wherein the blower is provided with a rectifying means for measurement. 4. A conveying means for conveying a container filled with a liquid, and a blower for blowing air to the container conveyed by the conveying means to emphasize a surface temperature difference between the gas-liquid interface in the container and the outside of the container. An infrared camera for photographing infrared radiant energy radiated from the container surface, first mirrors disposed on both sides of the container conveyed by the conveying means, and the container surface reflected by the first mirror A second mirror for guiding infrared radiant energy from the infrared camera to the infrared camera, and image processing means for processing an image taken by the infrared camera and detecting a portion having a remarkable change in density as a gas-liquid interface. A liquid filling height measuring device in a container. 5. A flow rate measuring means, a transport means for transporting a container filled with a liquid, and air blown to the container transported by the transport means on a detector section provided in the plurality of fixed quantity filling sections, A blower that emphasizes a surface temperature difference outside the container with respect to a gas-liquid interface in the container, an infrared camera that captures infrared radiation energy emitted from the container surface, and infrared radiation energy from the container surface transported by the transporting means An image processing means for processing an image photographed by the infrared camera and detecting a portion having a remarkable change in shading as a gas-liquid interface, wherein a liquid filling height measuring device in the container is provided, and the liquid filling height measuring device in the container is provided. Characterized in that the set value of a flow meter attached to each of the fixed quantity filling sections is changed based on the measurement result of (1).