JP2000258224A - Liquid quantity detecting mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid quantity detecting mechanism capable of detecting the quantity of a solution without being affected by foaming and turbidity. SOLUTION: This mechanism for detecting the liquid quantity of a translucent solution is provided with a translucent container 1 to hold a translucent solution, a non-translucent float 4 which floats in the translucent solution on the translucent container 1, and an optical sensor light emitting part 2 and an optical sensor light receiving part 3 on both sides of the translucent container 1 and detects the quantity of the solution by detecting the lower part of the non- translucent float 4 on the basis of the quantity of transmitted light measured by the optical sensor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mechanism for detecting a liquid amount in an apparatus for automatically supplying a solution to a container in all fields such as clinical examination, biochemistry, medicine, agriculture, engineering, and pharmacy. is there.

[0002]

2. Description of the Related Art A liquid amount detecting mechanism is used in a device for automatically supplying a solution to a container and stopping the supply when the solution reaches a specified amount. Although many mechanisms have been devised, the position of the liquid surface when the specified amount is reached is measured in advance, and the value is compared with the position of the liquid surface actually measured by the optical sensor. There is a way. The detection of the liquid level utilizes the difference in the amount of transmitted light in air, in a solution, and at the liquid level.

FIGS. 5 to 7 show the structure of the prior art, and FIG. 8 shows the relationship between the amount of transmitted light and the change over time when the solution is supplied.
An optical sensor light emitting unit 2 and an optical sensor light receiving unit 3 are provided on both sides of the container 1. Incident light 7 emitted from the optical sensor light emitting unit 2 passes through the container 1 and reaches the optical sensor light receiving unit 3 as transmitted light 8, and An electric signal corresponding to the amount of transmitted light is output.

When the supply of the solution from the solution supply port 6 is started, the incident light 7 emitted from the optical sensor light emitting section 2 passes through the air in the container 1 as the transmitted light 8 as shown in FIG. The light reaches the optical sensor light receiving unit 3. Thereafter, as shown in FIG. 6, when the liquid level 9 reaches the position of the optical sensor, the light is blocked by the liquid level 9 and the transmitted light amount becomes weaker than when transmitted through the air. Then, as shown in FIG. 7, when the solution reaches the position of the optical sensor, the amount of transmitted light shows the maximum value. FIG. 8 shows the relationship between the amount of transmitted light and the change over time when the solution is supplied.

Focusing on this phenomenon, it is possible to determine that the liquid level 9 has been detected when the threshold value is A and the value is not more than A in FIG. When the threshold value is set to B and a value equal to or more than B is indicated, it can be determined that the liquid level has changed into the solution.

[0006] The specified amount is detected by adjusting the position of the optical sensor so that the position of the liquid surface measured by these methods matches the position of the liquid surface in the case of the specified amount.

[0007]

In the case of a normal light-transmitting solution, detection can be performed by the conventional technique. However, it is difficult to detect a solution such as sodium dodecyl sulfate (hereinafter referred to as an SDS solution) that foams or becomes turbid due to a change in temperature.

When the method of detecting the liquid surface by the threshold value A in FIG. 8 is applied to the SDS solution, bubbles 10 generated on the liquid surface 9 block light transmission as shown in FIG.
In some cases, only a light amount equal to or less than the liquid level 9 can be transmitted. In this case, as shown in FIG. 10, the amount of transmitted light in the air falls below the threshold value A, and an erroneous determination that the liquid level 9 reaches the position of the sensor occurs.

As a method for avoiding this, there is a method using the threshold value B in FIG. However, when turbidity occurs, as shown in FIG. 11, the amount of transmitted light in the solution may decrease to become less than the amount of transmitted light in the air. In this case, FIG.
As shown in FIG. 2, the amount of transmitted light in the solution falls below the threshold value B, and the supply cannot be stopped even though the specified amount cannot be detected and the solution has reached the specified amount. Sometimes.

[0010]

The above object can be attained by detecting the lower part of the non-light-transmitting float in which the non-light-transmitting float is floated in the solution and immersed in the solution.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 to 3 show an example of a mechanism for carrying out the method of the present invention, and FIG. 4 shows the relationship between the amount of transmitted light and the change over time when a solution is supplied. As shown in FIG. 1, the optical sensor light emitting unit 2 and the optical sensor light receiving unit 3 are provided on both sides of the container 1.
, And there is a float 4 in the container 1. Float 4
Is arbitrary, but it is necessary to select a material in accordance with the specific gravity of the solution so that the lower portion is immersed when floating in the solution. Optical sensor light emitting unit 2 and optical sensor light receiving unit 3
Is disposed at a position where the float 4 blocks light with the container 1 being empty. The float 4 is fixed by a partition plate 5 so as to be able to move up and down so as not to move in the container 1 in the horizontal direction.
The lower part of the partition plate 5 is open, and the entire inside of the container 1 has a uniform liquid level. The solution supply port 6 is provided at a position that does not block the optical path.

As shown in FIG. 2, foaming starts simultaneously with the supply of the SDS solution. Light emitted from the optical sensor 2 is blocked by the float 4 and does not reach the optical sensor 3 at all regardless of the presence or absence of bubbles. Thereafter, as shown in FIG. 3, when the amount of the solution increases, the float 4 starts to float. When the lower part of the float 4 exceeds the position of the optical sensor, light is transmitted and reaches the sensor light receiving unit 3.

FIG. 4 shows the relationship between the amount of transmitted light and the change over time when the solution is supplied. At the beginning of the supply, there is bubbling, but since it is blocked by the float 4, the amount of transmitted light is zero and there is no change, so that the influence of the bubbling can be removed. After that, the float 4 starts to float, and the light blocked by the float 4 is transmitted. By detecting this change, the specified amount can be detected in the same manner as when the liquid level is detected.

Also in this method, since the determination is made using the transmitted light amount in the solution, the influence of turbidity can be considered. However, the transmitted light amount to be compared is completely zero because it is blocked by the float, and the threshold value can be set to any value other than zero. That is, the effect of turbidity can be removed as long as it is not turbid enough to completely block light.

[0015]

According to the present invention, it is possible to detect the amount of a bubbling and turbid solution without being affected by the solution.

[Brief description of the drawings]

FIG. 1 is a side view showing an empty state in an embodiment for carrying out a method of the present invention.

FIG. 2 is a side view showing a state at the beginning of pouring a solution in one embodiment for carrying out the method of the present invention.

FIG. 3 is a side view showing a state where a predetermined amount of a solution is supplied in an embodiment for carrying out the method of the present invention.

FIG. 4 is a graph showing the relationship between the amount of transmitted light and the change with time of supply in the method of the present invention.

FIG. 5 is a side view showing a state in which a solution is empty by a conventional method.

FIG. 6 is a side view showing a state in which a solution is poured by a conventional method.

FIG. 7 is a side view showing a state in which a prescribed amount of a solution is supplied by a conventional method.

FIG. 8 shows the relationship between the amount of transmitted light and the change with supply time in a conventional method,

FIG. 9 is a side view showing a case where a bubble portion is detected by a conventional method.

FIG. 10 is a graph showing the influence of bubbles on the relationship between the amount of transmitted light and the change with time of supply in a conventional method.

FIG. 11 is a side view showing a case where turbidity is detected by a conventional method.

FIG. 12 is a graph showing the influence of turbidity on the relationship between the amount of transmitted light and the change with time of supply in a conventional method.

[Explanation of symbols]

In the figure, 1 is a container, 2 is an optical sensor light emitting unit, 3 is an optical sensor light receiving unit, 4 is a float, 5 is a partition plate, 6 is a solution supply port, 7 is incident light, 8 is transmitted light, 9 is liquid level, 10 is a foam.

Claims (1)

[Claims] 1. A light-transmitting container for holding a light-transmitting solution, a non-light-transmitting float floating in the light-transmitting solution in the light-transmitting container, and an optical sensor for transmitting light through the light-transmitting container. Wherein the amount of the solution is detected by detecting the lower part of the light non-transmissive float based on the amount of transmitted light measured by the optical sensor. mechanism.