JP3899605B2 - Measuring method of liquid concentration - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a liquid concentration measuring method for measuring dissolved oxygen concentration, water hardness, water pH value, and the like used for industrial water and domestic water.
[0002]
[Prior art]
Conventionally, water supplied to a boiler or the like is supplied after being softened by a water softener or the like, and inspecting the degree or propriety of the water softening is performed by injecting a chemical solution into a liquid to be measured contained in a transparent container. A colorimetric measurement method is known in which stirring is performed and the change in hue of the liquid to be measured is measured by the transmitted light intensity of a projector. However, in the measurement of the concentration of the liquid to be measured in this colorimetric measurement method, the hue may change depending on the alkalinity contained in the liquid to be measured. ing. M alkalinity is mainly used for the measurement of the alkalinity.
[0003]
[Problems to be solved by the invention]
In view of the above problems, an object of the present invention is to provide a measuring method for measuring the liquid concentration based on the M alkali concentration contained in the liquid to be measured.
[0004]
[Means for Solving the Problems]
This invention is made in order to solve the said subject, Comprising: It is the method of measuring the density | concentration of a to-be-measured liquid by making a to-be-measured liquid react with a chemical | medical solution and detecting the discoloration of the to-be-measured liquid by this reaction. A predetermined determination table is selected based on the measured value of the M alkali concentration of the liquid to be measured, and the liquid concentration is measured using the determination table.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of the present invention will be described. The present invention includes a transparent container for storing a liquid to be measured, a chemical liquid injection means for the transparent container, a stirring means provided in the transparent container, and the transparent A plurality of detecting means for detecting discoloration of the liquid to be measured in the container; a mechanism for introducing the liquid to be measured into the transparent container; a mechanism for discharging the measured liquid to be measured from the transparent container; And a liquid concentration measuring device including a controller for controlling each mechanism. The present invention is characterized in that the controller includes a plurality of determination tables for determining the liquid concentration based on the M alkali concentration contained in the liquid to be measured.
[0006]
The plurality of determination tables include, for example, determination tables in which the M alkali concentration contained in the liquid to be measured is classified into three stages (30 ppm or less, 30 to 60 ppm, 60 ppm or more).
[0007]
The measuring device reacts the liquid to be measured with a chemical solution, detects discoloration of the liquid to be measured due to this reaction by a plurality of detection means, and automatically specifies the concentration of the liquid to be measured. The means is a liquid discharge device that presses and closes the elastic tube between the pressure roller and the arcuate guide portion by the rotational movement of the pressure roller, and discharges the liquid quantitatively, and the stirring means is disposed in the transparent container. A stirrer containing a magnet is inserted into the stator, and a stator having an electromagnetic coil is inserted into the outer peripheral wall of the transparent container corresponding to the position where the stirrer is located, and holding means for supporting the stator is provided. A stirring device, wherein the plurality of detection means further include a colorimetric detection mechanism including a plurality of light emitters and light receivers such as LEDs and phototransistors, and a function of determining a detected measurement value. The introduction mechanism, the a lower portion configured to connect the supply line with a valve of the transparent container and said discharge mechanism has a structure of connecting the discharge line to the top of the transparent container.
[0008]
The method for measuring the liquid to be measured in the measuring apparatus having the above configuration selects a predetermined determination table based on the measured value of the M alkali concentration of the liquid to be measured, and inputs the determination table to the controller. Then, based on the output signal from the controller, a pre-cleaning step is performed in which the liquid to be measured is introduced into the transparent container containing the liquid to be measured and the liquid is washed while being stirred. Next, a predetermined amount of the liquid to be measured is supplied into the transparent container, and a chemical liquid injection process is performed in which a predetermined chemical liquid is injected while stirring the liquid to be measured stored in the transparent container, and the process proceeds to the next measurement process. This measurement step includes measured values of the transmitted light intensity of the first light source composed of the light emitter and the light receiver of the first detection device and the transmitted light intensity of the second light source composed of the light emitter and the light receiver of the second detection device. The transmitted light intensity ratio (transmitted light intensity after color change / transmitted light intensity of the liquid to be measured before liquid reagent injection) is calculated based on the above, and the hardness of the liquid to be measured is measured with the determination table based on the calculated value. Perform the measurement process. Next, the measurement liquid is introduced into the transparent container, and the measurement process liquid is washed away while being washed, and a washing process is performed to complete the measurement of the concentration of the measurement liquid.
[0009]
As described above, according to the measurement method of the present invention, the predetermined determination table is selected based on the measured value of the M alkali concentration of the liquid to be measured, and the concentration of the liquid to be measured is measured using the determination table. The concentration can be measured accurately.
[0010]
【Example】
Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings. In the specific embodiment described here, a hardness measuring apparatus that measures the hardness of water by using a liquid reagent and discharging the liquid reagent will be described as an embodiment when the present invention is implemented. FIG. 1 is an explanatory cross-sectional view schematically showing the configuration of a liquid concentration measuring apparatus (hardness measuring apparatus in this embodiment) embodying the present invention.
[0011]
In FIG. 1, a hardness measuring apparatus according to the present invention basically includes a transparent container 1 having a plurality of measuring means for measuring transmitted light intensity for measuring discoloration of a liquid to be measured, and a liquid reagent in the transparent container 1. The liquid ejection device 2 for ejection and a controller (not shown) incorporating a plurality of determination tables according to the present invention are configured.
[0012]
First, the outline of the transparent container 1 that contains the liquid to be measured will be described. The transparent container 1 is a cylinder formed by molding an acrylic resin, and a lid for connecting a liquid ejection device 2 to be described later to the upper part. A member 3 is provided, and a stirring device 4 as stirring means for stirring the liquid to be measured is provided at the lower part. As a mechanism for introducing the liquid to be measured into the transparent container 1 and a mechanism for discharging the liquid to be measured from the transparent container 1, an electromagnetic valve 5 and a constant flow valve are provided at predetermined positions above the stirring device 4. 6 and a supply line 8 having a filter 7 are connected, and a discharge line 9 is connected to a predetermined position above the supply line 8, and small-hole flow paths 10, 10 are respectively connected to the transparent container 1 of each connection portion. It is drilled. Further, in this embodiment, as a measuring means for measuring the discoloration of the liquid to be measured in the transparent container 1 at a predetermined position outside the transparent container 1, in this embodiment, a light emitting body 11 such as an LED or a phototransistor and a light receiving body 12 are used. A colorimetric detection mechanism, a first detection device (not shown) having a function of determining a detected measurement value, and a second detection device (including a light emitter 19 and a light receiver 20 similar to the first detection device). (Not shown). Both the detection device, the stirring device 4 and the electromagnetic valve 5 are connected to a controller (not shown) via signal lines (not shown).
[0013]
As shown in FIG. 1, the lid member 3 is fixed to the upper end portion of the transparent container 1 by an appropriate means, and a hole 13 for inserting the distal end portion of the liquid ejection device 2 is provided at the center portion. .
[0014]
As shown in FIG. 1, the stirrer 4 has a stirrer 14 including a magnet inserted on a protrusion (reference numeral omitted) provided at the center of the bottom surface of the transparent container 1. A stator 15 having an electromagnetic floating coil is fitted into the outer peripheral wall of the transparent container 1 corresponding to the part to be performed, and holding means for supporting the stator 15 (for example, a concave groove is provided in the lower part of the transparent container 1, A configuration in which a clip is inserted and fixed in this groove portion is provided. The stator 15 is connected to an electric conductor (not shown) for supplying a current.
[0015]
Now, as shown in FIG. 1, the liquid ejection device 2 that ejects a liquid reagent into the transparent container 1 is connected to a lower part of the tank 16 for storing the liquid reagent and a hole 13 in the lid member 3 with a chemical injection pump 17. The liquid reagent supply line 18 provided is connected. For example, a roller pump device or a tube pump device is used as the chemical injection pump 17 and is connected to the controller (not shown) via a signal line (not shown). Then, the liquid reagent is discharged quantitatively based on the output signal from the controller.
[0016]
Next, the determination table according to the present invention will be described. This concentration determination table is a determination table corresponding to a change in hue depending on the M alkali concentration in the liquid to be measured. For example, when the M alkali concentration of the liquid to be measured is 30 ppm or less, the first table is used. When the alkali concentration is 30 to 60 ppm, the second table is set. When the M alkali concentration is 60 ppm or more, a three-level determination table is set, and these three tables are input into the controller (not shown). is doing. The adaptive determination table is selected based on the measured value of the M alkali concentration of the liquid to be measured, and the concentration of the liquid to be measured is specified by the determination table.
[0017]
As shown in FIG. 2, the hardness measurement method of the liquid to be measured in the hardness measuring apparatus having the above-described configuration first selects a predetermined determination table based on the measured value (for example, 50 ppm) of the M alkali concentration of the liquid to be measured. In this embodiment, the second table) is input to the controller (not shown). Then, based on the output signal from the controller, the electromagnetic valve 5 of the supply line 8 is opened to supply the liquid to be measured into the transparent container 1 containing the liquid to be measured, and at the same time, the stirring device 4 is turned on and the transparent liquid is supplied. A step of pre-cleaning the inside of the container 1 is performed. Next, the stirring device 4 is turned off, and a water supply step is performed in which a predetermined amount of liquid to be measured is supplied into the transparent container 1 and the electromagnetic valve 5 is closed. Next, the transmitted light intensity of the liquid to be measured before liquid reagent injection is measured by the light emitters 11 and 19 and the light receivers 12 and 20 of the first detector (not shown) and the second detector (not shown), The measured value is input to a controller (not shown). Then, the chemical injection pump 17 is turned on simultaneously with turning on the stirring device 4 to perform a chemical liquid injection process for injecting a liquid reagent from the tank 16 into the liquid to be measured, and the process proceeds to the next measurement process. This measuring step includes the transmitted light intensity of the first light source composed of the light emitter 11 and the light receiver 12 of the first detection device, and the transmitted light of the second light source composed of the light emitter 19 and the light receiver 20 of the second detection device. Calculate the transmitted light intensity ratio (transmitted light intensity after discoloration / transmitted light intensity of the liquid to be measured before liquid reagent injection) based on the measured values of the intensity, and calculate the hardness of the liquid to be measured based on the calculated values. A measurement step for measuring with the determination table is performed. In this measurement step, specifically, the concentration of the liquid to be measured is specified based on the calculated value of the transmitted light intensity ratio of the first detection device and the second detection device. That is, it is specified by the concentration curve of the determination table set by the M alkali concentration (50 ppm) in the liquid to be measured shown in FIG. In this embodiment, the measured concentration of the liquid to be measured is within a preset concentration (for example, 0.5 ppm). Next, after introducing the liquid to be measured into the transparent container 1 to wash away the measured liquid to be measured and stirring it, a washing process is performed, and a series of measurement of the hardness of the liquid to be measured is completed. FIG. 4 shows concentration determination curves of the first, second, and third determination tables corresponding to changes in hue depending on the M alkali concentration in the liquid to be measured.
[0018]
【The invention's effect】
As described above, according to the present invention, a method for measuring the concentration of a liquid to be measured by reacting the liquid to be measured with a chemical solution and detecting a color change of the liquid to be measured due to this reaction, Since the predetermined determination table is selected based on the measured value of the M alkali concentration and the liquid concentration is measured using the determination table, the liquid concentration of the liquid to be measured can be accurately measured.
[Brief description of the drawings]
FIG. 1 is an explanatory cross-sectional view schematically showing a configuration of a liquid concentration measuring apparatus embodying the present invention.
FIG. 2 is an explanatory diagram showing a flow of a measuring method according to the present invention.
FIG. 3 is an explanatory diagram illustrating a relationship between a first light source and a second light source for measuring a liquid concentration and a determination curve of a determination table.
FIG. 4 is an explanatory diagram showing density determination curves of first, second, and third determination tables.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Transparent container 2 Liquid discharge apparatus 4 Stirring apparatus 11 Luminescent body (1st detection apparatus)
12 Photoreceptor (first detector)
19 Light emitter (second detector)
20 Photoreceptor (second detector)

Claims (1)

A method of measuring a concentration of a liquid to be measured by reacting the liquid to be measured with a chemical solution and detecting a change in color of the liquid to be measured due to this reaction, wherein a predetermined value is determined based on a measured value of M alkali concentration of the liquid to be measured. A method for measuring a liquid concentration, comprising: selecting a determination table and measuring the liquid concentration using the determination table.

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