JPH06242071A - Residual chlorine meter equiped with automatic calbration function - Google Patents

Abstract

PURPOSE:To allow accurate automatic calibration by diluting hypochlorite substantially equal to the concentration of chlorine in a liquid to be measured every time when calibration is performed, measuring the conductivity thereof, and then identifying the concentration of chlorine based on the relationship between the chlorine concentration and the output from a conductivity meter. CONSTITUTION:Under measuring mode, solenoid valves V3c, V3b are opened to feed a liquid M to be measured to a residual chlorine meter 6 where the quantity of residual chlorine is measured. When a calibration mode is commanded 10, solenoid valves V1, V2 are opened and predetermined quantity of liquid is introduced, respectively, from a hypochlorite tank 1 and a pure water tank 2 into a stirring tank 3. Subsequently, the valves V1, V2 are closed. The mixed liquid is stirred 4 and diluted to a ppm order substantially equal to that of residual chlorine in the liquid M. Chlorine content of the mixture liquid is converted by a conductivity sensor 7 into an electric signal which is further converted through a conductivity converter 5 into a predetermined signal which is fed to a chlorine meter 6. The chlorine meter 6 perform calibration based on the signal thus received according to a prestored relationship between the quantity of residual chlorine and the electric signal from the conductivity sensor 7. Valves V4a, V4c are then opened to discharge the mixture liquid.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention automatically re-dilutes a chlorine concentration of a liquid to be measured by re-diluting hypochlorite diluted to a stable concentration to a chlorine concentration of a liquid to be measured every time calibration is performed. The present invention relates to a residual chlorine meter with an automatic calibration function that is calibrated.

[0002]

2. Description of the Related Art FIG. 2 is a block diagram showing a main portion of a conventional residual chlorine meter with an automatic calibration function described in Japanese Utility Model Laid-Open No. 17656/1990. In the figure, 21 is a flow path to which the solution M to be measured is supplied, 22 is a three-way solenoid valve that switches between the flow path 21 and the flow path 23 through which the calibration standard solution S is flown, and 24 is a three-way solenoid valve 2.
A constant flow rate pump 25 provided downstream of 2 is a residual chlorine sensor for measuring the effective chlorine concentration in the measurement liquid by a polarographic method, and the waste liquid is discharged from the flow path 26.

Reference numeral 27 is a purified water supply means for supplying a constant high-concentration NaCl aqueous solution, and 29 is a predetermined amount of the NaCl aqueous solution and purified water introduced from the salt water supply means 27 and the purified water supply means 28, and a metal inactive liquid is mixed in these solutions. It is a standard solution generating means in which an electrode pair is immersed. The inside of the standard solution generating means 29 is partitioned by a diaphragm 29a, which is electrically conductive but does not allow passage of molecules having a certain size or more, such as a Teflon film, and chambers A and B are formed. Of these, the chamber A is provided with an anode 29b, and the chamber B is provided with a NaCl electrolytic solution and is provided with a cathode 29c.

Reference numeral 30 denotes a constant current source for supplying a constant current between the electrodes of the standard solution generating means. The solution in the chamber A is stirred by a stirrer 35 to make the NaCl concentration uniform,
The constant current source 30 is turned on, and a current is passed between the electrodes 29b and 29c for a certain period of time. As a result, a certain amount of Cl is applied to the electrode 29b.
₂ occurs. An arithmetic control unit 31 performs various arithmetic processing (including sensitivity adjustment) on the detection signal of the sensor 25, and gives a control signal to the constant current source 30, the three-way solenoid valve 22, etc.
Is a stirrer.

In the above structure, the three-way solenoid valve 22 is switched to the flow path 21 side at the time of measurement, and the measured liquid M is supplied to the sensor 25 by the constant flow pump 24. The detection output S ₁ from the sensor 25 is given to the arithmetic control unit 31, is subjected to various arithmetic processing, and then output as an instruction output S ₂ .
When a calibration start signal is input at the time of calibration, a control signal is given from the arithmetic control unit 31 to the purified water supply means 28 and the salt water supply means 27, and a predetermined amount of purified water and NaCl aqueous solution is supplied to the standard solution generating means 2.
Introduced in 9. After stirring by the stirrer 35 to make the concentration uniform, the constant current source 30 is turned on to generate the standard solution generating means 2
A current is passed between the electrodes of 9 for a certain period of time.

This produces a certain amount of available chlorine,
The standard solution generating means 29 stores the calibration standard solution L having a constant effective chlorine concentration. After that, the three-way solenoid valve 22 is switched to the standard solution generating means 29 side, and the standard solution L is supplied to the sensor 25 for automatic calibration. In the automatic calibration, for example, sensitivity adjustment is automatically performed so that an instruction output corresponding to the effective concentration of the standard solution L is output. After the calibration is completed, the three-way solenoid valve 22 is switched, the measured liquid M is supplied to the sensor 25 by the constant flow pump 24, and the measurement is returned to.

[0007]

However, in the residual chlorine meter with the automatic calibration function having the above-described structure, the standard solution generating means is divided into a chamber with a diaphragm, and one chamber is provided with a diluted NaCl aqueous solution and a positive electrode. A NaCl electrolyte and a negative electrode are placed in the chamber, and a certain amount of Cl ₂ is obtained by passing an electric current through these electrodes for a certain period of time. However, the apparatus becomes complicated and a reproducible calibration solution is obtained. There was a problem that it was difficult.

The present invention has been made in order to solve the above-mentioned problems of the prior art. The hypochlorite diluted to a stable concentration is rediluted to the chlorine concentration of the liquid to be measured at each calibration. An object of the present invention is to provide a residual chlorine meter with an automatic calibration function, which measures the conductivity and identifies the chlorine concentration from the relationship between the chlorine concentration measured in advance and the output of the conductivity meter to perform calibration.

[0009]

In order to solve the above problems, the present invention provides a hypochlorite tank containing hypochlorite diluted to a stable concentration, and a pure water containing pure water. An aquarium,
A stirring tank for introducing a predetermined amount of the hypochlorite and pure water to store a mixed solution thereof, a conductivity meter for storing the mixed solution in the stirring tank to measure the conductivity of the mixed solution, and the stirring tank The polarographic expression for identifying the chlorine concentration from the relationship between the chlorine concentration measured in advance and the output of the conductivity meter while inputting the signal of the conductivity meter together with measuring the chlorine concentration of the mixed solution of A residual chlorine meter and a control means for controlling a series of operations from the measurement mode to the calibration mode are provided, and the calibration is performed based on the chlorine concentration of the mixed solution.

[0010]

[Function] A predetermined amount of hypochlorite and pure water diluted to a stable concentration is introduced to prepare dilution water of ppm order to be measured. The sensor (residual chlorine meter) stores in advance the relationship between the chlorine concentration and the output of the conductivity meter. Diluting water in the ppm order of hypochlorite is easy to decompose and unstable, but each time it is calibrated, conductivity is measured and calibration is performed based on the relationship between the chlorine concentration and the output of the conductivity meter. .

[0011]

The present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of an embodiment of a residual chlorine meter with an automatic calibration function of the present invention. In FIG. 1, the solid line indicates piping and the dotted line indicates electric signal wiring. 1 is a hypochlorite tank which stores a solution having a stable concentration in which pure water is diluted with about 6 to 7% by weight of hypochlorite, 2 is a pure water tank, and 3 is a stirring tank. A predetermined amount of liquid is introduced from the chlorate tank 1 and the pure water tank 2, and pp
The dilution water of m order is stored. Inside the stirring tank 3, a stirrer 4 for stirring the inside of the tank and a conductivity sensor 7 are arranged.

[0012] 5 is a conductivity converter, 6 is a residual chlorine meter, 10
Goes from measurement mode to calibration mode (or vice versa)
Control device for controlling a series of operations, V₁, V₂Is a two-way electromagnetic
Valve, V ₃, V_FourIs a three-way solenoid valve. Smell of the above structure
First, determine the relationship between the chlorine concentration and the output of the conductivity meter.
It In this case, the stirring tank 3 is empty and the solenoid valve V₁~ V_FourThe ba
All the lubes are closed.

The solenoid valves V ₁ and V ₂ are opened, a predetermined amount of liquid is introduced from the hypochlorite tank 1 and the pure water tank 2, and after introduction, the solenoid valves V ₁ and V ₂ are closed. These mixed liquids are stirred by the stirrer 4, and are diluted to the ppm order which is approximately the same as the residual chlorine amount of the fluid to be measured by adjusting the opening / closing time and the flow rate of each. The chlorine content of the mixed liquid in the stirring tank 3 is converted into an electric signal by the conductivity sensor 7,
It is converted into a predetermined signal by the conductivity converter 5 and transmitted to the residual chlorine meter 6.

In this case, the residual chlorine amount on the order of ppm is accurately measured by a separately prepared chlorine meter for a laboratory. The dilution concentration (including pure water alone) is changed by a plurality of types by the above-described method, and the measured relationship between the amount of residual chlorine and the electrical signal of the conductivity meter is stored in the residual chlorine meter. After that, the mixed liquid in the stirring tank 3 is discharged by opening V _4a and V _4c of the three-way solenoid valve.

In the measurement mode, V _3c and V _3b of the solenoid valve V ₃ are opened to supply M to be measured liquid to the residual chlorine meter 6 to measure the amount of residual chlorine contained in the measured liquid. When the calibration mode is commanded by the control device 10, the solenoid valves V ₁ and V ₂ are opened to introduce a predetermined amount of liquid from the hypochlorite tank 1 and the pure water tank 2, and then the solenoid valves V ₁ and V ₂ Will be closed. These mixed liquids are stirred by the stirrer 4, and the opening / closing time and flow rate of the respective solenoid valves V ₁ and V ₂ are controlled by the control device 1.
By adjusting it to 0, it is diluted to the order of ppm, which is approximately the same as the residual chlorine content of the fluid to be measured.

The content of chlorine in the mixed liquid in the stirring tank 3 is converted into an electric signal by the conductivity sensor 7, converted into a predetermined signal by the conductivity converter 5 and transmitted to the residual chlorine meter 6. The residual chlorine meter calibrates based on the electric signal based on the relationship between the amount of residual chlorine stored in advance and the electric signal of the conductivity meter. In this case, the mixed liquid in the stirring tank 3 is discharged by opening V _4a and V _4c of the solenoid valve 4 without passing through the residual chlorine meter 6. The zero adjustment is performed by filling the stirring tank 3 with pure water only.

[0017]

As described above, according to the present invention, the electrical conductivity is measured by re-diluting the hypochlorite diluted to a stable concentration to the chlorine concentration of the liquid to be measured at each calibration. However, since the chlorine concentration is identified and calibrated based on the relationship between the chlorine concentration measured in advance and the output of the conductivity meter, an accurate residual chlorine meter with an automatic calibration function can be realized with a relatively simple device. .

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a residual chlorine meter with an automatic calibration function of the present invention.

FIG. 2 is a configuration diagram showing a main part of a conventional residual chlorine meter with an automatic calibration function.

[Explanation of symbols]

1 hypochlorite tank 2 deionized water tank 3 stirred tank 4 agitator 5 Conductivity converter 6 residual chlorine meter 7 the conductivity sensor 10 the control device V _1, V ₂ 2-way solenoid valve V _3, V ₄ 3-way solenoid valve

Claims (1)

[Claims] 1. A hypochlorite tank for storing hypochlorite diluted to a stable concentration, a pure water tank for storing pure water, and a predetermined amount of the hypochlorite and pure water. And a conductivity meter for measuring the conductivity of the mixed solution, which is stored in the stirring tank, and chlorine of the mixed solution introduced into the stirring tank. A polarographic residual chlorine meter that measures the concentration and inputs the signal of the conductivity meter and identifies the chlorine concentration from the relationship between the chlorine concentration measured in advance and the output of the conductivity meter, and from the measurement mode to the calibration mode And a control means for controlling a series of operations,
A residual chlorine meter with an automatic calibration function, characterized in that calibration is performed based on the chlorine concentration of the mixed solution.