JPH10115585A - Method for self-diagnosing apparatus for measuring color and turbidity of liquid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To self-diagnose deterioration of a light source by respectively monitoring a plurality of kinds of light immediately after dispersion for detecting when an amount of certain light is at a defined value or less and when it is at a defined ratio or less with respect to a light amount at an initial period for starting lighting. SOLUTION: Five optic filters 4 including a chromaticity measuring filter C, a turbidity measuring filter T and tristimulus value filters R, G, B are placed on a rotating disk to constitute a rotating-disk-type spectrographic part 3. Light which has transmitted through the respective optic filters 4 is divided into a measuring light path 7 and a reference light path 8 by a half mirror 5, and transmission light amounts corresponding to the respective optic filters 4 on a side of the reference light path 8 are measured by a photoelectric converter 12. A signal processing part 18 judges the light source to be deteriorated when one or more of the five measured values is at a defined value or less. In addition, a ratio of the transmission light amount corresponding to each of the optic filters 4 measured at an initial period for starting lighting up the light source 1 stored in the signal processing part 18 and each of current transmission light amounts is obtained, and if one or more ratios in the light amounts is at a defined value or less, the light source is judged to be deteriorated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to chromaticity, turbidity, coloring degree,
The present invention relates to a self-diagnosis method for an apparatus for automatically measuring a coloring index of a liquid represented by a hue or the like.

[0002]

2. Description of the Related Art Conventionally, color and turbidity of various liquids have been measured in various industrial fields. It requires that water tests be conducted at least once a day for multiple tap water in the water supply area.

[0003] Regarding the measurement of color and turbidity, it is recognized that color is measured by chromaticity as a substitute and turbidity is measured by turbidity. Meters are often used. According to the “Water Water Test Method”, pp. 73-74 (1993) (supervised by the Ministry of Health and Welfare, Water Environment Department, published by Japan Water Works Association), the chromaticity is “soluble substances contained in water”. And the degree of yellowish to yellowish brown exhibited by the colloidal substance ", and a visual colorimetric method and an absorbance measurement at a wavelength of 390 nm are shown as official methods. On the other hand, the turbidity is defined as “the degree of turbidity of water”, and the turbidimetric method by visual observation and the measurement of absorbance at a wavelength of 660 nm are indicated as official methods.

[0004] Various devices for automatically measuring chromaticity and turbidity are already on the market. These devices include, as basic elements, a light source for measurement, a flow cell for putting a liquid of a sample, a spectroscopic unit including each optical filter capable of selecting a wavelength of light emitted from the light source and transmitted through the flow cell to light of 390 nm and 660 nm, Consisting of a spectroscopy unit and a photodetector that measures light from a light source passing through the flow cell,
390nm and 66
Light of 0 nm is transmitted in order, the absorbance is measured, and each measured value is converted into chromaticity and turbidity from a conversion formula or conversion table and output.

A color / turbidity measuring device is disclosed in Japanese Patent Application Laid-Open No. 8-6878 in addition to the above-described chromaticity and turbidity measuring type.
No. 8 has published an application. This is because R (red), G (green), B (blue)
By adding each optical filter that can select the light of the three primary colors, and analyzing each absorbance of the three primary colors, the measured values of the degree of coloration and the hue, which are indicators of coloring closer to visual inspection, can be compared with those of conventional colors. It is output in addition to the measured values of degree and turbidity.

In some cases, these color / turbidity measuring devices are housed in an outdoor-installed panel as part of a tap water quality automatic monitoring device, and are continuously operated automatically. At that time, it is measured that the device has an automatic calibration function. This is effective for maintaining accuracy. As a method of the automatic calibration, in general, correction of fluctuation of a measured value by monitoring a light source light amount, zero point correction by measuring clean water through a water purification filter, and the like are performed. Japanese Patent Application Laid-Open No. 7-204110 discloses a method of calibrating a span point by inserting a color filter into an optical path to create the same state as that in which water is pseudo-colored.

In actual measurement, the water quality measurement value of the automatic tap water quality monitoring device is transmitted to a host computer in a central monitoring station via a communication line. Further, when the color and turbidity sensor measures an abnormality of the water quality exceeding the upper and lower limit values during the automatic operation, a water quality warning signal is simultaneously transmitted to the host computer. Therefore, particularly high reliability is required for the water quality measurement value as well as the water quality abnormality alarm output.

[0008]

The color / turbidity measuring device outputs a measured value or an alarm of the water quality abnormality not only when the water quality deteriorates but also when the measuring device fails. That is, despite the normal water quality,
Due to the failure of the measuring device, there is a possibility that the alarm of the water quality abnormality is erroneously issued. The main causes and problems of specific malfunctions are shown below.

The first factor is deterioration of the light source. In the conventional apparatus, the light amount of the light source lamp is directly monitored, and when the light amount becomes zero, it is determined that the lamp has run out, and when the light amount becomes less than a certain light amount, it is determined that the lamp has deteriorated. But,
In the color and turbidity sensor described above, the light from the light source
0 nm, 660 nm, R (red), G (green), and B (blue) light are separated and used, and the selected light is used. Therefore, the light amount of each wavelength varies, and the light amount of each wavelength is also different. Since the degree of the decrease is different, the degree of deterioration of the light of each wavelength cannot be sufficiently grasped simply by directly monitoring the decrease in the light amount of the light source lamp, and the measurement accuracy cannot be maintained.
For this reason, there is a possibility that an abnormal water quality measurement value is output even though the water quality is not abnormal.

The second factor is a trouble in a piping system for injecting the sample water into the flow cell. Specifically, sample water may not be filled in the flow cell due to clogging of a pipe, failure of an electromagnetic valve, or the like, and an incorrect measurement value may be output because there is no sample water. In order to detect that the sample is not injected into the flow cell, there is a method of adding a flow rate detector to the pipe, but there is a problem that the cost increases.

The third factor is a trouble of the movable portion for inserting the color filter when the automatic span calibration is performed.
If span calibration is performed without a colored filter inserted, the measuring device will be calibrated to the wrong span.If the colored filter is not removed, the measured value will be added to the span equivalent to the colored filter, resulting in an incorrect measured value. May be output.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and an object of the present invention is to determine whether a sensor failure or water quality abnormality occurs when a color / turbidity measurement device outputs an abnormal measurement value. It is an object of the present invention to provide a method for more accurately determining a water quality abnormality by adding a self-diagnosis function for determining the abnormality.

[0013]

SUMMARY OF THE INVENTION A light source for measurement, a spectroscopic unit that converts light emitted from the light source into a plurality of types of spectra and transmits the same, and a sample liquid through which the plurality of types of split light are transmitted. A flow cell for holding, a photodetector for detecting the amount of light transmitted through the flow cell, and a signal for calculating and outputting at least one of chromaticity, turbidity, coloring degree, and hue as a measurement value based on a signal from the photodetector. In the method for self-diagnosis of a liquid color / turbidity measuring device provided with a processing unit, the means for diagnosing deterioration of the first light source and abnormal injection of sample water into the second flow cell among the problems described above are as follows It is on the street.

First, as a first light source deterioration diagnosis method, the light amounts of a plurality of types of light immediately after passing through the spectroscopy unit are monitored, and the light amount of at least one light is reduced to a predetermined value or less. If one of the following conditions occurs, or if the light intensity of at least one light falls below a predetermined ratio with respect to the initial light intensity of the light source, it is diagnosed that the light source has deteriorated. I decided to.

This diagnostic method first focuses on the fact that the light converted into a plurality of types of spectra by the spectroscopic unit has different amounts of light due to differences in the respective wavelength ranges. When the light amount of at least one light falls below a predetermined value, it is determined that the light source has deteriorated. This means that an absolute amount of light required for measurement is secured for light in a wavelength region having the smallest amount of light. Next, when the light amount of at least one light falls below a predetermined ratio with respect to the light amount at the start of lighting of the light source, it is determined that the light source has deteriorated because the absolute value of the light amount can be secured. However, if the light intensity is too low due to the deterioration of the intensity at the beginning of lighting, the distribution of the spectrum or the angular distribution of the radiant intensity may change, adversely affecting the measurement accuracy. Therefore, this adverse effect is prevented by providing a second criterion. By performing a self-diagnosis of determining that the light source has deteriorated when one or both of the above two determination criteria are satisfied, the deterioration of the light source can be accurately determined.

Next, as a second method of diagnosing the abnormality of the injection of the sample water into the flow cell, the measured light amounts of the respective transmitted lights when the flow cell is filled with the clean water, and the respective light amounts when the flow cell is filled with the sample liquid are described. Among the ratios of the transmitted light and the measured light intensity, the measured light intensity ratio of at least one set of light falls within a predetermined range, and the measured light intensity ratio of at least one set of light is reduced to that of another set of light. When the value divided by the measured light amount ratio falls within a predetermined range, it is determined that the liquid sample is abnormally injected into the flow cell.

This diagnostic method is based on the problem that when the flow cell is not filled with sample water due to a trouble in the piping system and the flow cell is empty, the amount of light of each wavelength passing through the flow cell is equal to the amount of light when filled with clean water. It is noted that the compared ratios each show a substantially constant value. This is because the attenuation of light in air is negligibly small compared to the measurement accuracy, and the difference between the refractive index of water and the refractive index of air reflects and absorbs light passing through the flow cell surface.
The magnitude of the diffusion is explained by producing a certain difference between when filled with water and when filled with air. For this purpose, the ratio of the measured light quantity of each transmitted light when the flow cell is filled with clean water and the measured light quantity of each transmitted light when the flow cell is filled with the sample liquid is defined in advance as the ratio of the measured light quantity of at least one light. It can be determined that the flow cell is empty by checking whether the flow cell is in the range. Further, by checking whether the value obtained by dividing the measured light intensity ratio of each of at least one light by the measured light intensity ratio of the other light is within a predetermined range, the liquid to the flow cell can be more reliably checked. Self-diagnosis of abnormal sample injection.

A light source for measurement, a spectroscopic unit for converting light emitted from the light source into a plurality of types of spectra and transmitting the same, a flow cell for holding a sample liquid through which the plurality of types of split light are transmitted, and a flow cell A photodetector that measures the amount of light transmitted therethrough, a calibration coloring filter, and a mechanism for inserting the calibration coloring filter into the optical path between the spectral unit and the photodetector;
A liquid color including a calculation unit for performing a calibration calculation and a signal processing unit for calculating and outputting at least one of chromaticity, turbidity, coloring degree, and hue as a measurement value based on the result of the calibration calculation and a signal from the photodetector. In the turbidity detecting device, the means for diagnosing the third colored filter insertion abnormality among the above problems is as follows.

This is because when the light amount ratio of light when the calibration coloring filter is inserted into the optical path and when it is not inserted into the optical path is out of a predetermined range, the insertion abnormality of the calibration coloring filter is determined. Diagnose. This diagnostic method has an automatic span calibration function, and in a turbidity measuring device with a movable part into which a colored filter is inserted, the difference between the presence or absence of the colored filter and the transmitted light amount when there is an inserted The focus is on the fact that the ratio of the amount of transmitted light when there is no insertion changes by the amount of light attenuation of the colored filter.
That is, by checking whether or not the light amount ratio is within a preset range, it is possible to perform a self-diagnosis of the insertion abnormality of the calibration coloring filter.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention is shown in FIGS. Hereinafter, the first method of the present invention will be described together with the configuration of the apparatus with reference to these drawings. The light source 1 comprises a tungsten lamp having a broad emission spectrum and a stabilized power supply. The lens 2 converts the light from the light source into a parallel light beam. As shown in FIG. 2, the rotating disk-type spectroscopy unit 3 is configured by arranging five optical filters 4 on a rotating disk. Each filter of the spectroscopy unit has a chromaticity measurement filter C and a turbidity measurement filter T both having a center wavelength of 660 nm.
The filters for G and B tristimulus values are 570 nm,
It has a center wavelength near 535 nm and 445 nm.
The spectral transmittance of these three primary color filters is based on the total relative spectral sensitivity ratio from the light source to the photoelectric converter.
It is determined in consideration of the emission spectrum of the light source and the light receiving sensitivity spectrum of the photoelectric converter so as to be equal to the ratio of the integral values of the color matching function distribution of the tristimulus values determined by the (International Commission on Illumination). The rotating disk-type spectroscopic unit 3 is rotated by a motor, so that each optical filter is sequentially inserted into the measurement optical path.
The half mirror 5 divides the light transmitted through the spectral filter into a measurement optical path 7 and a reference optical path 8. The measuring cell 9 has an optical window 10 made of Pyrex glass,
It has a measurement optical path length L of about mm or more. Both the photodetector 11 for measurement light and the photodetector 12 for reference light use silicon photodiodes.

The measurement procedure is as follows. At the time of calibration, the measurement cell 9 is filled with blank water, which is a colorless and transparent standard solution, and in this state, the T, C, R, G, and B of the optical filter 4 are supplied to the measurement optical path 7.
Are sequentially inserted, and the transmitted light _amounts I _T0 , I _C0 , I _R0 ,
Measure _IG0 and _IB0 . Next, the measuring cell 9 is filled with tap water as a measuring sample, and the transmitted light amounts I _T1 , I _C1 , I
Measure _R1 , _IG1 , and _IB1 . The signal processing unit 18 including the preamplifier 13, the A / D converter 14, the CPU 15, the RS232C 16, and the communication modem 17 calculates the measured values of the turbidity T and the chromaticity C based on these data according to [Equation 1] and [Equation 2]. ]
And the measured value of the coloring degree Q is represented by [Equation 3] to [Equation 6].
Calculate by Thereafter, the data obtained by the calculation is transmitted to the host computer via the public line.

[0022]

(Equation 1)

[0023]

(Equation 2)

[0024]

(Equation 3)

[0025]

(Equation 4)

[0026]

(Equation 5)

[0027]

(Equation 6)

Here, K _T , K _C , K _R , K _G , K _B ,
K _Q is the device constant, x ₀ is the x coordinate of the uncolored point W in the chromaticity diagram (x, y plane in FIG. 3) determined by CIE, and x ₁ is W
The straight line connecting (x ₀ , y ₀ ) and C (x, y) is the x coordinate of a point S (x ₁ , y ₁ ) where the straight line intersects the contour of the chromaticity diagram. The measured value of the hue is divided into the xy plane of the chromaticity diagram, and the signal processing unit 1
8 indicates that the hues to be output are red, yellow, white,
By storing a sample coordinate-hue conversion table stored as black and blue as data, determining which section the sample coordinate C (x, y) falls into, and outputting the hue assigned to that section. Done.

For the deterioration of the light source, the following two judgments are applied.
The first is that the T, C, R,
G, B optical filters 4T, 4C, 4R, 4G, 4B
Transmitted light amount I corresponding to_RT, I_RC, I_RR, I_RG, I_RBThe light
The measurement is performed by the electric converter 12, and the signal processing unit 18
At least one of the transmitted light intensity measurements
If the value falls below the previously defined value, it is determined to be deteriorated.
The second is the lighting of the light source stored in the signal processing unit 18.
Transmitted light corresponding to each optical filter 4 measured at the beginning of the start
Quantity I_RT0, I_RC0, I_RR0, I_RG0, I_RB0And the current
I which is the ratio to the measured transmitted light quantity_RT/ I_RT0, I_RC/ I
_RC0, I_RR/ I_RR0, I_RG/ I_RG0, I _RB/ I_RB0The value of the
At least one of the transmitted light ratios is specified in advance.
If the value is equal to or less than the set value, it is determined to be deteriorated. This first
When either or both of the two
Self-diagnose source deterioration. This is the first decision
Absolute light required for measurement for light in the wavelength range where the amount of light is small
Amount, and in the second judgment, the absolute value of the amount of light
Light intensity is too low compared to the initial light intensity
The distribution of the spectrum changes,
Changes in angle distribution adversely affect measurement accuracy
It has the meaning of preventing things from happening. Above 2
Light source if one or both of the two criteria
By performing self-diagnosis to judge deterioration,
Deterioration can be accurately determined.

Next, a second embodiment of the present invention will be described with reference to FIG. The second method is a ratio in which the amount of light of each wavelength transmitted through the flow cell is compared with the amount of light when the flow cell is filled with clean water when the flow cell is empty because the flow cell is not filled with sample water due to a trouble in the piping system. Note that each of them shows a substantially constant value. The chromaticity of the spectroscopic unit 3 in the ratio of the transmitted light amount of the measurement optical path 6 transmitted through the measurement cell 8 filled with clean water and the transmitted light amount of the measurement optical path 6 transmitted through the measurement cell 8 filled with tap water as a measurement sample. The ratio of the amount of light transmitted through the filter ( _IC1 / _IC0 ) falls within a predetermined range, and the ratio of the amount of light transmitted through the chromaticity filter is divided by the ratio of the amount of light transmitted through the turbidity filter. When the value (I _C1 / I _C0 ) / (I _T1 / I _T0 ) falls within a preset range, a self-diagnosis of an abnormal injection of the liquid sample into the flow cell is made.

Finally, the third method has an automatic span calibration function, and includes a color having a movable portion into which the coloring filter 6 is inserted,
In the turbidity measuring device, there is the insertion of the coloring filter 6,
The difference between the two cases is that the ratio of the amount of transmitted light with insertion and the amount of transmitted light without insertion changes by the amount of light attenuation of the colored filter 6. If the ratio ( _IT2 / _IT1 ) of the ratio of the light amount _IT2 when the calibration coloring filter 6 is inserted into the optical path to the light amount _IT1 when the calibration colored filter 6 is not inserted is out of the preset range, the calibration is performed. Self-diagnosis of abnormal insertion of the color filter 6 for use.

[0032]

The present invention relates to a self-diagnosis method for an apparatus for automatically measuring a coloring index of a liquid represented by chromaticity, turbidity, coloring degree and hue, and relates to deterioration of a light source, piping for injecting sample water into a flow cell. Due to a system failure, a sensor failure such as a movable part that inserts a colored filter when having automatic span calibration, etc., the water quality is not abnormal, but a water quality abnormality alarm is erroneously issued. Then, the signal processor analyzes the color and turbidity measurement values, and easily performs self-diagnosis of these sensor abnormalities, determines whether there is a sensor failure or water quality abnormality, and more accurately detects the water quality abnormality. Provide a method of determining.

[Brief description of the drawings]

FIG. 1 is a diagram showing a basic configuration of a liquid color / turbidity measuring device of the present invention.

FIG. 2 is a diagram showing a configuration of a rotating disk-type spectroscopic unit.

FIG. 3 is a diagram showing a three-dimensional color space;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Light source 2 Lens 3 Rotating disk-type spectral part 4 Optical filter 4T Turbidity filter T 4C Chromaticity filter C 4R Red filter R 4G Green filter G 4B Blue filter B 5 Half mirror 6 Coloring filter 7 Measurement optical path 8 Reference optical path 9 Measurement cell Reference Signs List 10 optical window 11 photodetector for measurement light 12 photodetector for reference light 13 preamplifier 14 A / D converter 15 CPU 16 RS232C 17 communication modem 18 signal processing unit

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hideo Kanai 1-1, Tanabe Nitta, Kawasaki-ku, Kawasaki, Kanagawa Prefecture Inside Fuji Electric Co., Ltd. (72) Inventor Fumio Toyama No. 1, Tanabe Nitta, Kawasaki-ku, Kawasaki, Kanagawa Prefecture No. 1 Fuji Electric Co., Ltd. (72) Inventor Kenji Harada 1-1, Tanabe Nitta, Kawasaki-ku, Kawasaki, Kanagawa Prefecture Inside Fuji Electric Co., Ltd. (72) Inventor Hiroshi Tada No. 1, Tanabe Nitta, Kawasaki-ku, Kawasaki, Kanagawa Prefecture No. 1 Fuji Electric Co., Ltd.

Claims (3)

[Claims] A light source, a spectroscopic unit that converts light emitted from the light source into a plurality of types of spectra and transmits the light, a flow cell holding a sample liquid through which the plurality of types of split light are transmitted, and a flow cell. A photodetector that measures the amount of transmitted light, and chromaticity as a measurement value based on a signal from the photodetector,
In a liquid color / turbidity measuring device including a signal processing unit for calculating and outputting at least one of turbidity, coloring degree, and hue, the amount of light of a plurality of types of light immediately after passing through a spectroscopic unit is monitored. Either when the light intensity of one light falls below a predetermined value, or when the light intensity of at least one light falls below a predetermined ratio with respect to the initial light intensity of the light source. Happens,
A self-diagnosis method for a liquid color / turbidity measuring device, wherein the self-diagnosis is a deterioration of a light source. 2. A light source, a spectroscopy section for converting light emitted from the light source into a plurality of types of spectra and transmitting the same, a flow cell for holding a sample liquid through which the plurality of types of split light are transmitted, and a flow cell. A photodetector that measures the amount of transmitted light, and chromaticity as a measurement value based on a signal from the photodetector,
In a liquid color / turbidity measurement device provided with a signal processing unit for calculating and outputting at least one of turbidity, coloring degree, and hue, a measurement amount of each transmitted light when a flow cell is filled with clean water, and a sample liquid in a flow cell. Of the ratio of the measured light amount of each transmitted light when satisfying the condition, the measured light amount ratio of at least one set of light falls within a predetermined range, and the measured light amount ratio of at least one set of light is already reduced. Liquid color / turbidity measurement characterized by self-diagnosis of abnormal injection of liquid sample into the flow cell when the value divided by the measured light intensity ratio of one set of light falls within a predetermined range. Device self-diagnosis method. 3. A light source, a spectroscopic section for converting light emitted from the light source into a plurality of types of spectra and transmitting the light, a flow cell holding a sample liquid through which the plurality of types of split light are transmitted, and a flow cell. A photodetector for measuring the amount of transmitted light, a color filter for calibration, a mechanism for inserting the color filter for calibration into the optical path between the spectroscopic unit and the photodetector, an operation unit for performing the calibration operation, and Chromaticity, turbidity, coloring degree, and a signal processing unit that calculates and outputs at least one of hue as a measurement value based on the result and the signal from the photodetector.
In the turbidity measuring device, when the light intensity ratio between the case where the calibration coloring filter is inserted into the optical path and the case where the calibration coloring filter is not inserted is out of the preset range, the insertion of the calibration coloring filter is diagnosed as abnormal. A self-diagnosis method for a liquid color / turbidity measurement device.