JPS6288923A - Measuring method for quantity of liquid in container - Google Patents

Abstract

PURPOSE:To easily confirm the remaining amount of liquid by utilizing differences in heat conduction and transmission between the liquid part and gas part in a container and grasping a speed difference in color change sensuously by using a reversible temperature-responsive coloring compound. CONSTITUTION:Liquefied gas is charged in a metallic cylinder 1 and a liquid crystal compound layer 2 applied and formed on the external wall surface of this cylinder 1 in a vertical line shape colors in green at a 20 deg.C room temperature and in royal purple in a higher temperature range, e.g. at 25 deg.C. A scale 3 which indicates the internal capacity is provided on the top surface of the liquid crystal compound layer 2. When a heater 2 is put closer to the liquid crystal compound layer 2 which colors in green at a 20 deg.C environmental temperature to make it turn royal purple quickly and then the layer is left as it is, the part under the certain place of the liquid crystal compound layer 2 turns green gradually so that a distinctive boundary line appears between the color changing part and said royal purple part several seconds later. The remaining amount is measured by reading the boundary line on the scale 3.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for measuring the amount of liquid present in a non-transparent container.

(Prior Art) Propane gas for fuel is well known as a liquefied gas stored in a metal container, but various other liquefied gases are also used in the industrial and medical fields. In some cases, the remaining amount of these liquefied gases can be determined using a pressure gauge that indicates the pressure inside the container.

In addition, so-called sprays that contain insecticides and hair conditioners sealed together with Freon gas do not have any particular means of indicating the amount remaining, and you can usually feel the amount remaining by the feeling of weight when you hold it in your hand or shake it. It is. In addition to airtight containers, there are paper containers for milk, alcoholic beverages, etc.7 that have a window that allows you to see inside so that you can see the amount remaining after opening the container.However, pressure gauges can be used even if the contents are expensive. It cannot be attached to just about any object, and it is often impossible to provide a transparent window depending on the material and structure of the container. (Problems to be Solved by the Invention) The present invention: It is an object of the present invention to provide a method for easily measuring the amount of liquid remaining in a container from outside the container, regardless of the material or structure of the container.

(Means for Solving the Problems) The present inventor has focused on temperature-responsive liquid crystals, which are used in thermometers that color-display temperature numbers corresponding to the environmental temperature, and non-destructive inspections that detect heat-generating parts. However, they discovered a method to measure the amount of liquid in a container by taking advantage of its ability to sensitively detect temperature changes.

That is, in the present invention, in a state in which a reversible temperature-responsive coloring composition is brought into close contact with the outer wall surface of a non-transparent container containing a liquid, the temperature is raised above the ambient temperature or lowered below the ambient temperature. In the process of gradually returning the coloration from the stage where the coloration changes at ambient temperature to the coloration at ambient temperature, we utilized the fact that the coloration state of the temperature-responsive coloring composition differs up and down with the position corresponding to the liquid level as the boundary. It is something.

As the temperature-responsive coloring composition used in the present invention, in addition to the temperature-responsive liquid crystal compositions described above, reversible coloring materials such as thermostatic paints can be used.

Liquids to be measured include liquefied gas, water, oil,
Any liquid such as chemical solution, solid dispersion, solid solution, etc. can be used, and the container storing these liquids is not limited to a closed cylinder or tank, but an open type. Any type of container may be used, including, but not limited to, its size.

Regarding the material of the container, it can be made of metal, glass, synthetic resin, paper, etc., but it is not suitable for containers that use insulation to block heat conduction between the liquid and the outer wall of the container, such as household pots. , excluded.

To attach the temperature-responsive coloring composition to the outer wall of the container,
It can be made into a liquid and applied directly to the outer wall of the container, formed into a sheet and attached to the outer wall of the container with glue, or magnetically fixed. Just attaching it is fine. Since the temperature-responsive coloring composition is used to check the high and low levels of liquid volume, it is recommended that it be provided in a shape that is continuous in the vertical direction with respect to the outer wall of the container so as to sufficiently cover the range of fluctuations in liquid volume. good. It is preferable to provide it vertically or in a straight line. Of course, even in the case where the liquid crystal composition is not displayed as a single unit but as a plurality of independent parts, such as continuous steps, it is sufficient that the display in the vertical direction of the container is continuous as an aggregate.

Prior to measurement, the temperature-responsive coloring composition is heated or cooled, but it is not necessary to keep it in close contact with the outer wall of the container at this point. After applying heat or cooling to give the coloring composition a color change, it is preferable to bring it into close contact with the outer wall of the container, but if heating or cooling does not adversely affect the quality of the content liquid, The container may remain in close contact with the wall.

Any means for applying heat may be used, such as hot air or electric heating, and a simple method is simply by transmitting body temperature from the palm of the hand to impart a color change to the coloring composition. Further, a method in which a resistance layer is provided on the lower surface of the coloring composition and resistance heat generation is generated each time a measurement is made is suitable for use in industrial fields such as large tanks.

On the other hand, the common method of lowering the temperature below the ambient temperature is to use cold air, but if it is stored separately from the container until the measurement, it is also possible to use a cooler. For warmth, a thermos is used.

When the temperature of the coloring composition is raised or lowered with the coloring composition in close contact with the outer wall of the container, if the temperature of the content liquid follows the temperature rise or fall of the coloring composition, the liquid volume may change. Since there is a risk that measurement may become impossible, it is important to apply temperature changes locally and in a short period of time.

In order to restore the color from the stage where the color is different from that under the environmental temperature to the color under the environmental temperature, it is better to leave it as it is under the environmental temperature condition.

In the process of gradual recovery, the coloring composition always passes through a coloring state in which different colors appear above and below, with the position corresponding to the liquid level as the boundary.

Therefore, it is extremely easy to visually determine the liquid level. Additionally, if a color discrimination device is used, the amount of liquid can be read electrically.

Furthermore, if a volumetric scale is placed on the temperature-responsive coloring composition or on the outer wall surface of the container according to the pre-measured internal volume, the remaining amount can be confirmed in a specific quantity.

(Operation) The principle of the present invention is derived from the fact that the rate of heat absorption or heat transfer in a liquid and in a gas are completely different. In other words, the height level at which the liquid content exists in the container,
The fact that it is an interface between a liquid and a gas means that the rate of heat absorption or heat transfer is different above and below this interface.

Therefore, if a reversible temperature-responsive color-forming composition that has been brought into a coloring state different from that under environmental temperature conditions by applying heat is brought into close contact with the above-mentioned interface, the portion that comes into contact with the liquid through the container will absorb heat. , because the transmission is fast, it quickly returns to the colored state at ambient temperature; on the other hand, in the area above the boundary where only gas exists in the container, it returns to the colored state at ambient temperature. will be delayed.

In other words, during the process in which the entire temperature-responsive coloring composition dissipates and releases the applied heat and returns to the ambient temperature, a temperature difference occurs between the upper and lower sides of the boundary surface, and this temperature difference causes the colored color to change. This difference is used to determine the liquid level.

The above explanation is also valid when using a temperature-responsive coloring composition set at a temperature lower than the ambient temperature due to the difference in heat transfer rate.

(Example) Examples of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing a state in which a liquid crystal composition is brought into close contact with a liquefied gas cylinder.

In FIG. 1, a metal cylinder 1 is filled with liquefied gas. The liquid crystal composition layer 2 coated and formed on the outer wall surface of the cylinder 1 in a vertical straight line forms a green color at room temperature of 20°C, and a blue-purple color at a higher temperature range, for example, 25°C. It is prepared as follows. This liquid crystal composition layer 2
A scale 3 indicating the internal volume is provided on the top surface. At an environmental temperature of 20°C, when a heater is brought close to the liquid crystal composition layer 2 which is colored green, the color quickly changes to blue-purple, and then left for a while. The lower part gradually turned green, and a clear border line appeared between it and the blue-purple part above.

The remaining amount was measured by reading this boundary line at scale 3.

After that, the bluish-purple part gradually returned to green, returning to the state it was in before the heat was applied.

(Effects of the Invention) As described in the paper, the present invention takes advantage of the fact that there is a difference in heat absorption and transmission between the liquid part and the gas part in a container, and uses a reversible temperature-responsive coloring composition to achieve this effect. This makes it possible to visually indicate the difference in speed of discoloration. According to the present invention, it is now possible to use the liquid content without wasting it even in the medical field and some industrial fields, where conventionally the container was replaced with a new one for safety reasons because the remaining amount could not be confirmed. Ta. Moreover, it can be carried out extremely easily and reliably, so it can be applied in a wide range of applications.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a state in which the method of the present invention is applied to a liquefied gas cylinder. 1...Cylinder 2...Liquid crystal composition 3...Volume scale O/]

Claims (2)

[Claims] (1) With the reversible temperature-responsive coloring composition in close contact with the outer wall surface of a non-transparent container that stores a liquid, coloring occurs by raising the temperature above the ambient temperature or cooling it below the ambient temperature. The liquid in the container takes advantage of the fact that the coloring state of the temperature-responsive coloring composition differs up and down at the position corresponding to the liquid level, in the process of gradually returning to the coloring at the environmental temperature from the stage where the temperature is changing. How to measure quantities. (2) The method for measuring the amount of liquid in a container according to claim 1, characterized in that a volumetric scale is provided on the temperature-responsive coloring composition or on the outer wall of the container.