JPH06281565A - Absorbance type analyzer - Google Patents

Abstract

PURPOSE:To clean a measuring cell by the minimum amount of a cleaning liquid, by spraying the cleaning liquid and cleaning the inner wall of the measuring cell where a transmission light passes, filling the cell with a reference water, detecting the stain of the cell by the light penetrating the reference water, and controlling the cleaning liquid sprayed to the inner wall. CONSTITUTION:When a solenoid valve V1 is opened, a to-be-measured solution SL0 is supplied from a nozzle 14A to a measuring cell 13 with a flow rate regulated by a valve N and discharged through a discharge port 13B. When the cell 13 is to be cleaned, a solenoid valve V4 is opened after the solenoid valve V1 is closed, thereby to discharge the solution SL0 from a discharging line D. Thereafter, a solenoid valve V3 is opened to supply a cleaning liquid SL1 to the nozzle 14A. Since the solution SL0 is already discharged outside, the cell 13 can be cleaned efficiently. The cleaning process is based on the result after a reference water SL2 is fed to the cell 13 from a supplying line B and the degree of dirt of the cell 13 is measured, that is, the cleaning process is executed in accordance with the degree of dirt of the cell. In this manner, the cell 13 can be cleaned by the minimum amount of the cleaning liquid without a large time required.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorbance type analyzer for measuring the intensity of light passing through a solution to be measured and analyzing the solution to be measured, and more specifically, to a cleaning liquid on the inner wall of a dirty measuring cell. The present invention relates to an absorbance type analyzer capable of jetting and automatically cleaning dirt on a measuring cell.

[0002]

2. Description of the Related Art FIG. 6 is a block diagram of a conventional absorbance type analyzer. In the figure, 1 is a cell having a glass window 1A on the optical path surface, and a solution to be measured S _L0 is supplied from an inlet 1B and discharged from an outlet 1C. Reference numeral 2 is a lens for converting the light of the lamp 3 into a parallel light flux. The intensity of the light emitted from the lens 2 to the cell 1 is measured by the detector 4, converted into an electric signal, and then transmitted to the measurement circuit 5. The measuring circuit 5 is a detector 4
A calculation process is performed on the basis of the electric signal input from to obtain characteristics such as turbidity of the measured solution S _L0 .

[0003]

In order to remove the dirt generated on the inner wall of the measuring cell by the solution to be measured, such a conventional absorbance type analyzer is designed to discharge the solution to be measured and then remove the cell window. It had a drawback that it had to be cleaned and required a lot of time for cleaning.

The present invention has been made in view of the above point, and is designed to inject the cleaning liquid onto the inner wall of the measuring cell to clean the inner wall of the measuring cell according to the degree of contamination of the measuring cell. It is an object of the present invention to provide an absorbance type analyzer that does not require the above and can wash the measurement cell with a minimum amount of the washing solution.

[0005]

In order to achieve such an object, the present invention is to measure the intensity of light passing through a solution to be measured contained in a measuring cell to analyze the solution to be measured. In the analyzer, a cleaning unit that sprays a cleaning liquid on the inner wall of the measurement cell through which the transmitted light passes, and a reference water supply unit that fills the measurement cell with reference water after cleaning the inner wall by the cleaning unit. And a control unit that determines the contamination of the measurement cell based on the transmitted light that passes through the measurement cell filled with the reference water and controls the cleaning liquid sprayed from the cleaning unit.

[0006]

The control means determines the contamination of the measurement cell based on the transmitted light that passes through the measurement cell filled with the reference water, and determines the cleaning cycle according to the degree of contamination. The cleaning means is on / off controlled based on the valve control signal of the control means, and cleans the measurement cell by injecting a cleaning liquid onto the inner wall of the measurement cell at each cleaning cycle.

[0007]

An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a configuration diagram showing an embodiment of the absorbance analyzer of the present invention. In the figure, 10 is a lamp which is a light source, 11 is a first lens for collimating the light from the lamp 10 into a parallel light flux, and 12 is a diaphragm, which narrows the parallel light flux emitted from the first lens 11 to an appropriate light flux diameter d. . 13 is a measuring cell,
Reference numeral 14 is a cleaning means for supplying a cleaning liquid S _L1 for cleaning the glass window 13A of the measurement cell 13, and a pair of nozzles 14A are provided facing the glass window 13A.

The nozzle 14A is provided at a position deviated from the optical path through which the parallel light flux passes, that is, at a position projecting a distance δ into the measurement cell 13 so as not to block the light passing through the solution S _L0 to be measured. Has become. Reference numeral 15 is a second lens, which forms an image on the detector 16 of the parallel light flux that has passed through the measurement cell 13. Reference numeral 17 denotes a measurement circuit, which is based on the detection signal D _i input from the detector 16 and is based on the turbidity of the measured solution S _L0.
Obtain data such as chromaticity.

In this embodiment, the reference water supply means for supplying the reference water S _L2 is shared with the cleaning means 14 for supplying the cleaning water to the measurement cell, and the reference water S supplied to the measurement cell is used. _L2 is generally pure water, which is highly transparent. Further, the solution to be measured S _L0 is also supplied to the measurement cell 13 from the same cleaning means 14.

V ₁ is a solenoid valve provided on the supply line A of the measured solution S _L0 , V ₂ is a solenoid valve provided on the supply line B of the reference water S _L2 , and V ₃ is a supply line of the cleaning water S _L1 . An electromagnetic valve provided at C, V ₄ is an electromagnetic valve provided at the discharge line D, and N _{1 to} N ₃ are valves for controlling the flow rate. Solenoid valve V
_{1 to} V ₄ and valves N _{1 to} N ₃ are controlled by a control unit (hereinafter, referred to as control means) 18, and the solution and flow rate supplied to the measurement cell are selectively controlled.

When the solenoid valve V ₁ is opened, the solution to be measured S _L0
Is supplied from the nozzle 14A to the measurement cell 13 at a flow rate adjusted by the valve N ₁ , and is discharged from the discharge port 13B.
To clean the measurement cell 13, after closing the solenoid valve V ₁ , open the solenoid valve V ₄ , discharge the solution to be measured S _L0 from the discharge line D, then open the solenoid valve V ₃ to supply the cleaning liquid S _{L 1} to the nozzle 14A. It is done by supplying. Cleaning of the measuring cell 13 has already been completed.
Since the measured solution S _L0 has been discharged, the cleaning is efficiently performed.

This cleaning process is carried out according to the degree of contamination, based on the result of measuring the degree of contamination of the measuring cell 13 by supplying the reference water S _L2 from the supply line B to the measuring cell 13. When the measured solution S _L0 is water with little contamination, the measured solution S _L0 is filtered by the filter 19 and used as the reference water S _L2 , and the washing water S _L1 is the valve N ₃ and the measured solution S _L0 is the measured solution S _L0 . It may be used after being boosted.

FIG. 2 is a block diagram showing the control means of the present invention in an extracted form. The cleaning cycle T is calculated from the detection signal D _i (i = 0 to n) obtained by the reference water S _L2 supplied to the measuring cell. _i
This is described by taking the case of setting (i = 0 to n) as an example. In the figure, reference numeral 18 ₁ denotes a cleaning cycle control unit which sets the cleaning cycle T _i in the cycle timer 18 ₂ based on the detection signal D _i of the detector 16 which is digitally converted by the A / D converter.

Reference numeral 18 ₃ is a first memory in which the first cleaning cycle T ₀ is stored, and reference numeral 18 ₄ is a second memory in which a detection signal D _i input from the detector 16 is stored. _i
Will be updated. The cleaning cycle control unit 18 ₁ sets the first cleaning cycle T ₀ to the cycle timer 18 ₂ at the same time when the operation is started, and 2
From the fourth time, the difference ΔD _{i + 1} between the detection signal D _i stored in the second memory 18 ₄ and the subsequently input detection signal D _{i + 1} is obtained, and the time table 18 ₅ is obtained based on the change amount. The cleaning cycle T _i selected from is set in the cycle timer 18 ₂ .

The cycle timer 18 ₂ outputs a control signal S ₁ to the sequence controller 18 ₆ when the set time has timed out. Sequence controller 18 _6, based on the control signals S ₁ inputted from the cycle timer 18 _2, and outputs a valve control signal S ₂ to S ₅ in the valve V ₁ ~V ₄ according to a predetermined sequence. Each valve V ₁ ~V _{4 is} turned on / off controlled based on the valve control signal S ₂ to S ₅ inputted from the sequence controller 18 _6.

FIG. 3 is a diagram showing changes in the contamination of the measuring cell, in which the abscissa indicates the elapsed time and the ordinate indicates the detection signal. The broken line in the figure shows how the detection signal drops when the cleaning operation is not performed, and the solid line shows the effect of the cleaning operation with the detection signal obtained with the reference water. D ₀ is a detection signal before the operation is started, D ₁ is a detection signal before the first cleaning is performed, and D ₂ is a detection signal before the second cleaning is performed. When the detection signal D _n falls below a certain standard before the n-th cleaning is performed, the measuring cell 13
Are washed by conventional methods.

The cleaning cycle control unit 18 ₁ includes the second memory 1
8 ₄ to obtain a difference _{ΔD n (ΔD n = D n} -D n-1) of the detection signal D _n that the stored detection signal D _n-1 and subsequently inputted, based on the amount of change [Delta] D _n An appropriate cleaning cycle T _n is selected from the time table 18 ₅ . The cleaning cycle T _n is _expressed by the following equation when the attenuation of the detection signal is ΔD _{n-1 in} the previous cleaning cycle T _n-1 . T _n = (T _n-1 / ΔD _n-1 ) × α where α is a predetermined coefficient.

Next, the operation of the absorbance analyzer of the present invention will be described with reference to a time chart. FIG. 4 is a time chart showing the cleaning cycle T, and FIG. 5 is a time chart showing the details of the cleaning work. (A) shows the operating state of the solenoid valve V ₁ ,
(B) shows the operating state of the solenoid valve V ₂ , (C) shows the operating state of the solenoid valve V ₃ , and (D) shows the operating state of the solenoid valve V ₄ .
The cleaning operation is performed for T _w time after T ₀ time from the start of measurement, and further for T _w time after T ₁ time.
After that, the measuring cell has a cleaning cycle T determined according to the dirt.
Cleaning is performed with _i .

(1) When the cleaning operation starts at time t ₁ , the solenoid valve V ₄
Is opened, and the measurement cell 13 discharges the measured solution S _L0 from the drain line D. (2) At time t ₂ , the discharge of the solution to be measured S _L0 is completed, and the solenoid valve V ₄ is closed and the solenoid valve V ₂ is opened. When the solenoid valve V ₂ is opened, the measuring cell 13 is supplied with the reference water S _L2 from the supply line B. (3) During the supply, the solenoid valve V ₄ is temporarily opened at time t ₃ . This is because the measured solution S _L0 remaining in the measuring cell 13 is quickly discharged from the measuring cell 13.

(4) At time t ₄ , the solenoid valve V ₂ is closed and the reference water S _L2 is measured. When the measurement of the reference water S _L2 is completed, the solenoid valve V ₄ is opened and the reference water S _{L2 is} discharged from the drain line D.
Is discharged. (5) When the reference water S _L2 is discharged from the drainage line D, the solenoid valve V ₃ is opened at time t ₅ , and the cleaning water S _L1 whose pressure is increased to, for example, 5 liters / min is supplied to the supply line by the valve N _2. It is jetted by C from the nozzle 14A to the glass window 13A for t _j time. (6) In this way, drainage and washing are performed alternately. At time t ₆ , the reference water S _L2 is again supplied from the supply line B to the measuring cell 1
3 and the zero point is calibrated at time t ₇ .

(7) When the zero point calibration is completed, the solenoid valve V ₄
Is opened and the reference water S _L2 is discharged from the measuring cell 13. (8) When the reference water S _L2 is discharged from the measurement cell 13, the solenoid valve V ₄ is closed, and the measured solution S _L0 is supplied to the measurement cell 13 from time t ₈ . As described above, in the present invention, the cleaning cycle is changed according to the contamination of the measuring cell, but the cleaning time T _W may be changed.

[0022]

As described above in detail, the absorbance analyzer of the present invention is designed to spray the inner wall of a dirty measurement cell with a cleaning liquid according to the degree of dirt of the measurement cell, so that the measurement cell is cleaned. The measurement cell can be cleaned with a minimum amount of cleaning liquid without requiring a large amount of time for cleaning.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of an absorbance analyzer of the present invention.

FIG. 2 is a block diagram showing a configuration in which control means of the present invention is extracted and shown.

FIG. 3 is a diagram showing a change in dirt of a measurement cell.

FIG. 4 is a time chart of the operation of the absorbance analyzer of the present invention, showing a cleaning cycle T.

FIG. 5 is a time chart showing the content of the cleaning work.

FIG. 6 is a configuration diagram of a conventional absorbance analyzer.

[Explanation of symbols]

13 Measuring Cell 14 Cleaning Means 14A Nozzle 18 Controlling Means 18 ₁ Cleaning Cycle Setting Section 18 ₆ Sequence Control Section

Claims (1)

[Claims] 1. An absorbance analyzer for measuring the intensity of light transmitted through a solution to be measured contained in a measurement cell to analyze the solution to be measured, wherein an inner wall of the measurement cell through which the transmitted light passes is washed with a cleaning liquid. Based on the transmitted light that passes through the reference water supply unit that fills the measurement cell with the reference water after the cleaning unit that sprays and cleans the inner wall by the cleaning unit, and the measurement cell that is filled with the reference water An absorbance analyzer, comprising: a control unit that determines the contamination of the measurement cell and controls the cleaning liquid sprayed from the cleaning unit.