JP3374939B2 - Dilution degree measuring device by dilution method and its measuring method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coloring degree measuring device used for controlling the water quality of, for example, sewage treatment wastewater and industrial wastewater, and more particularly to a coloring degree measuring apparatus using a dilution method.

[0002]

2. Description of the Related Art The degree of coloring, which is one of the indicators of the water quality of sewage treatment wastewater and factory wastewater, is the "level" or "strength" of the coloring of the wastewater, regardless of the type of impurities contained in the wastewater. Since it is difficult to measure it as objective data such as the concentration of heavy metal ions and other substances, it has been conventionally obtained by a sensory measurement method.

As the above-mentioned sensory measurement method, there are a chromaticity method (colorimetric method), a color contamination degree method, a dilution method and the like. Of these, the chromaticity method has been used for many years to control the water quality of sewage treatment effluent, and the sample and the chromaticity standard solution prepared in stages are compared with the naked eye, and the color matching the sample Is a method of calculating the chromaticity according to the platinum concentration and cobalt concentration of the chromaticity standard solution. When 1 mg of platinum and 0.5 mg of cobalt are dissolved in 1 liter of pure water, the coloring degree is 1 degree. Is calculated as

The color pollution degree method is a method specified in the Kawasaki City Pollution Control Ordinance and separates the color of the wastewater into three attributes of hue, lightness, and saturation. This is a method of calculating the color pollution degree by substituting the corresponding standard color chart (JIS Z8721) number into the following formula (1).

Color pollution degree = 3 (Vb-Vs) + Cs-Cb (1) where Vb: lightness of blank test (pure water), Vs: lightness of sample, C
b: Saturation of blank test, Cs: Saturation of sample.

Further, the dilution method was proposed by Yasuhiko Miyoshi, Toshio Nishiido, etc., Department of Water Quality, Institute of Environmental Science, Tokyo in recent years, and samples were successively purified with pure water at prescribed multiple ratios (for example, 10 times). Diluted and compared with the standard color (pure water), and the maximum dilution factor a _{1 that} can distinguish between the sample color and the standard color
Then, the minimum dilution factor a ₂ that cannot be distinguished is determined and substituted into the following formula (2) to calculate the common logarithmic value Ca of the coloring degree.

Ca = [log (a ₁ ) + log (a ₂ )] / 2 (2) The sensory measurement work until the above common logarithmic value Ca is calculated is 5
The coloring degree C of the sample is determined as 10 ^Cm from the arithmetic mean value Cm of the remaining three values excluding the maximum value and the minimum value, which is independently performed by a human monitor.

As described above, as the sample is diluted, the coloring degree shown by the above-mentioned dilution method decreases until the hue / saturation becomes unrecognizable. Since the comparison is made mainly on the basis of the lightness, different hues and saturations are obtained. It is possible to compare the degree of coloring among the samples, and it is shown that the coloring becomes invisible by diluting with the same number of dilution ratios as the degree of coloring, which is an advantage that the degree of coloring can be grasped intuitively.

Instead of the sensory measurement method based on the sense (visual sense) of the monitor as described above, an instrument measurement method using an optical instrument (spectrophotometer) for measuring the spectrophotometric distribution of the transmitted light of the sample is also carried out. There is. This device measurement method has the advantage that it is possible to build an automated system by combining it with a device that measures other data such as chlorine concentration or heavy metal concentration, and at the same time, it is possible to reduce the labor cost required for the measurement. is there.

According to this instrument measuring method, based on the measurement data output from the above optical instrument (spectrophotometer),
For example, the index calculated as follows is adopted as the coloring degree.

That is, as the first index, the tristimulus values (X, Y,
Z) is obtained, and the stimulus value Y of these is adopted. On the other hand, based on the chromaticity coordinate value xy derived from the above-mentioned three stimulus values (X, Y, Z) by the following formula (4), the “2 degree visual field XYZ system” is obtained. A total of three numerical values, i.e., the stimulus purity and the dominant wavelength, which are obtained from the "chromaticity diagram according to the present invention" are adopted as index values indicating the degree of coloring.

[0012]

[Equation 1]

As another index showing the degree of coloring, the above
Tristimulus value of each transmitted light of the sample and the pure water used as a standard
By the conversion shown in the following formula (5) based on X, Y, Z
Tristimulus value (L^*, A^*, B^*) Is calculated for each
Difference of stimulation value (ΔL^*, Δa ^*, Δb^*), And below
There is a method of adopting the color difference ΔE calculated by the formula (6).

[0014]

[Equation 2] The above X _n , Y _n , and Z _n are tristimulus values of standard light used for illumination. As another index, the light transmittance of the sample at a predetermined wavelength selected according to the dissolved substance is directly adopted as the degree of coloring.

[0015]

As described above, various numerical values are adopted as the index of the coloring degree, but it is generally desired to meet the following conditions.

[0016] That is, (a) it is possible to compare drainages of different hues, (b) the display of the measurement results roughly matches the visual impression of the human being, (c) the measurement is simple and inexpensive. That (d) can be expressed numerically, (e)
There are few differences among individuals and the measurement is reproducible. (F) It is possible to measure not only soluble substances but also colors exhibited by colloidal substances and suspending substances.

However, in any of the sensory measurement methods described above, it is inevitable that the degree of coloring derived will vary if the measurer (monitor) is different for the same measurement object, and the above condition (e) is completely satisfied. Can't reach Therefore, in order to ensure the reproducibility and stability of the above-mentioned coloring degree, it is necessary to perform a color vision test in advance when selecting a monitor, and to perform an appropriate work such as averaging the numerical values of a plurality of monitors. However, due to the recent increase in labor costs, the cost required for the measurement increases, and the above conditions (c) and (e) cannot be satisfied at the same time.

Further, in the sensory measuring method, each individual measuring operation itself is completed in a relatively short time by a skilled monitor, so that the water quality change to such an extent that there is no problem even if the measuring is performed at sufficient time intervals. This is an appropriate measurement method when the water temperature is slow, but when changes in the water quality of the above wastewater are rapid and need to be monitored almost continuously, the burden on the monitor that is bound during that time becomes excessive and the cost also increases. However, realization is virtually impossible.

The chromaticity method among the sensory measurement methods was developed to measure the degree of yellowish to yellowish brown color which is exhibited when the humic substance existing in soil is dissolved in water. For example, when changing to various hues such as wastewater from a dyeing factory, it is difficult to specify the chromaticity for wastewater having a hue different from the color exhibited by the humic aqueous solution, and the above condition (a) There are difficulties that do not fit.

Furthermore, although the degree of color contamination indicated by the above-mentioned color contamination method is chromatically grounded, since it is displayed as a numerical value unrelated to human vision, the degree of coloring of the wastewater can be intuitively determined. It is difficult to understand and does not satisfy the above condition (d).

Further, the above-mentioned instrument measuring method is based on the above condition (c)
Although (e) is completely satisfied, when the stimulus value Y as the index of the coloring degree, the dominant wavelength and the stimulus purity, and the color difference ΔE are adopted, these are chromatically valid values. , As in the case of the color contamination degree method in the sensory measurement method, it is not possible to intuitively know the color and concentration of the sample confirmed by the naked eye based on the above numerical values, and the above condition (d) is not satisfied. There is.

In the instrumental measurement method, when the light transmittance of the sample is used as an index of the degree of coloring, it is essentially impossible to compare the degree of coloring between samples having different hues, and the above condition (a) is satisfied. I can't.

Further, when the above-mentioned light transmittance is used as an index of the coloring degree, the measurement results for the same sample are inconsistent as described below. That is, for example, the red dye is the color most sensitive to human vision, and when a small amount of the green dye is added to a sample in which the red dye is dissolved, the red hue decreases and becomes a color close to purple. However, there is no change in the light transmittance at the wavelength corresponding to the absorption peak of the red dye, and if the light transmittance at the wavelength at the absorption peak of the green dye is taken into consideration, the light transmittance will decrease.

When the coloring degree of the sample having a color close to purple is measured by a sensory measurement method, for example, a dilution method,
This results in a result inconsistent with the above-mentioned light transmittance, in which the red color, which is sensitive to humans, becomes purple, which is difficult for humans to see, and thus the degree of coloring is significantly reduced.

In addition, when the degree of coloring of the sample is extremely large, the sample is appropriately diluted for measurement. When the light transmittance is divided by the dilution ratio of the sample after the dilution, the borrowed transmittance is Very small (eg 10 ^-4 % order),
The result may be difficult to understand perceptually.

Further, in an optical instrument such as a spectrophotometer used in the above instrument measuring method, a measurement cell for accommodating a sample to be measured may be contaminated by impurities contained in the sample, resulting in a measurement error. However, complicated maintenance such as frequent cleaning and replacement of the measuring cell is required.

The present invention has been proposed in view of the above-mentioned conventional circumstances, and adopts the advantages of the dilution method by the above-mentioned sensory measurement method, is easy to maintain, and is a coloring degree measuring apparatus capable of automating water quality management. It is an object of the present invention to provide a method for measuring the degree of coloring with the device.

[0028]

In order to achieve the above object, the present invention employs the following means. That is, FIG.
As shown in FIG. 3, a sample S diluted with pure water W is used as a test solution M, and the color of the sample S is colored based on the amount of transmitted light of the test solution M and the dilution ratio of the sample S in the test solution M. And a light detecting element 13 for detecting the amount of light transmitted through the measuring cell 11, a light source 12 for irradiating the measuring cell 11 with light, and a measuring cell 11 for measuring the degree of light.
And a supply path P _{in in which} a sample flow path Ps and a pure water flow path Pw, which are independent of each other, are joined at a predetermined position in the measurement cell 11 or on the upstream side of the measurement cell 11, the test liquid discharge channel and the sample liquid supply and discharge passage P constituted by P _out, the pure water passage disposed Pw was diluted pump 21 and the test liquid for discharging the M downstream of the measurement cell 11 sheet At least the sample flow path P among the discharge paths P
The coloring degree measuring apparatus by the dilution method is provided with a supply / discharge pump mechanism 2 including a discharge pump 22 arranged at a predetermined position on the downstream side of the confluence of s and the pure water flow path Pw.

Further, as shown in FIG. 2, the pure water flow path Pw.
A control cell 14 formed so as to irradiate light from a light source 12 common to the measurement cell 11 and a photodetector element 15 for detecting the amount of transmitted light of the control cell 14,
This is a coloring degree measuring device by the dilution method added to the transmitted light amount measuring unit 1 in the configuration shown in FIG.

Further, it is desirable that the spectral sensitivity characteristics of the photo-detecting elements 13 and 15 are approximated to the standard relative luminous efficiency characteristics. Further, based on the output from the transmitted light amount measuring unit 1, a flow rate control unit 31 that controls a flow rate difference ΔF between the dilution pump 21 and the discharge pump 22, and a sample in the test liquid M based on the flow rate difference ΔF. It is also possible to add the control means 3 including the dilution ratio calculator 32 that calculates the dilution ratio D of S.

As a first measuring method using the apparatus shown in FIG. 1, the flow rate difference ΔF obtained by subtracting the flow rate F _W of the dilution pump 21 from the flow rate F _M of the discharge pump 22 is set to zero or smaller than zero. Output T _{0 of the} photodetector 13
And the photodetector element 13 when the flow rate difference ΔF is gradually increased.
Of the output T ₁ and the displacement Δ between the outputs T ₀ and T _1.
The dilution ratio D of the sample S in the test liquid M is calculated based on the flow rate difference ΔF ₁ when t reaches the predetermined reference value Ta.

As a measuring method using the apparatus shown in FIG. 2, the two flow rate differences ΔF obtained by subtracting the flow rate F _W of the dilution pump 21 from the flow rate F _M of the discharge pump 22 are gradually increased from zero. Of the sample S in the test liquid M based on the flow rate difference ΔF ₁ between the dilution pump 21 and the discharge pump 22 when the difference Δt between the outputs of the photodetector elements 13 and 15 reaches a predetermined reference value ta. Be sure to calculate the dilution factor (D).

[0033]

According to the structure shown in FIGS. 1 and 2, the dilution po
Flow rate of pump 21 (hereinafter F_WOf the discharge pump 22
Flow rate (hereinafter F_MBy setting it smaller than
The sample flow path P_SSample flowing toward the measuring cell 11
Flow rate F of S_SIs both flow rate F _W, F_MFlow rate difference ΔF (= F
_M-F_W) Will be equivalent to.

As a result, the test liquid M in the measuring cell 11 is mixed at a ratio equal to the ratio of the flow rates F _W and F _S of the pure water W and the sample S. Therefore, since the dilution ratio D of the sample S in the test liquid M is a value obtained by dividing the pump flow rate F _W by the flow rate F _S of the sample S, this can be expressed by the pump flow rates F _W and F _M as follows: It is expressed as a two-variable function by the flow rates F _W and F _M as shown in A). For example, while the flow rate F _M of the discharge pump 22 is made constant, while changing the flow rate F _W of the dilution pump 21, the dilution ratio D Can be adjusted to any value.

[0035] _{D = F W / (F M} -F W) ... (A) In addition, when less than zero the flow rate difference ΔF is part of the pure water W is to flow back through the sample flow path Ps However, if it is not mixed with the sample S, it does not interfere with the measurement performed as described below. Rather, the sample channel Ps can be cleaned while supplying the pure water W to the measuring cell 1.

First coloring using the apparatus having the configuration shown in FIG.
First, the pump flow rate F_W, F_MFlow rate between
Only the pure water W is supplied to the measuring cell 11 with the difference ΔF set to zero,
The output T of the photodetector element 13 in this state₀Based on
To adopt. Next, the flow rate difference ΔF (however, F_W<F_M)
Is gradually increased, the output T of the photodetector element 13 thereafter is increased. ₁
Is the output T that is the above-mentioned standard₀Gradually decreases from the output T
₀When the amount of displacement Δt from reaches the reference value Ta,
Pump flow rate F_W, F_MIs calculated by substituting
The dilution ratio D is used as it is as the coloring degree.

In the above first measuring method, the reference value Ta
Is preset in the control means 5 in order to immediately adopt the dilution ratio D of the sample S in the test liquid M as the coloring degree, whereby the dilution method by sensory measurement depends on the visual sense of the monitor. Whether or not the test liquid M and the pure water W can be discriminated can be entrusted to the output of the photodetection element 13.

Therefore, when the reference value Ta is lower than, for example, an appropriate value, the coloring degree is calculated for the same sample S at a level higher than the coloring degree calculated by the conventional dilution method by sensory measurement. Conversely, when the level is set to a high level, a low value will be calculated. Therefore, in order to set the reference value Ta at an appropriate level, for example, a sample having a dilution ratio, which is recognized as indistinguishable from pure water by visual inspection of a monitor in a dilution method by sensory measurement, is used as the measurement cell 1 above.
No. 1 is set, and a plurality of measurements are performed with reference to the output level from the transmitted light amount measuring unit 1 at this time.

Further, in the apparatus having the structure shown in FIG. 2, only pure water W always flows into the reference cell 14 regardless of the flow rates F _M and F _W , so that the output of the photodetection element 15 corresponding to the reference cell 14 is output. Corresponds to the standard T ₀ in the first measurement method as it is, and the procedure of adjusting the flow rate until the output of the coloring degree is simplified, and at the same time, the pure water W is changed over time.
There is an advantage that the purity of the product itself decreases and even if it is colored extremely, it is guaranteed.

Photodetector 1 used in the above-mentioned structure
3, 15 preferably have a spectral sensitivity characteristic that covers at least the entire visible wavelength range so that the degree of coloring of the sample S of any color can be measured, and as shown in FIG.
By providing the spectral sensitivity characteristic close to the standard relative luminous efficiency characteristic, the output of the value according to the measurement by the naked eye can be obtained.

[0041]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram of a coloring degree measuring apparatus according to the present invention. As shown in FIG. 1, a measurement cell 11 containing a test liquid M to be measured, and a light source 12 arranged at a position facing one surface of the measurement cell 11 and irradiating the measurement cell 11 with light. And a transmitted light quantity measuring unit 1 including a photodetector 13 arranged on the opposite side of the measurement cell 11 from the light source 12 and detecting the quantity of light transmitted through the measurement cell 11.
Equipped with.

The test liquid supply / discharge path P connected to the measurement cell 11 joins the sample flow path P _S and the pure water flow path P _W , which are independent of each other, at a predetermined position on the upstream side of the measurement cell 11. The supply path P _in and the discharge path P _out for discharging the test liquid M _{in the} measurement cell 11 on the downstream side of the measurement cell 11 are configured. The sample flow path P _S and the pure water flow path P _W may be merged in the measurement cell 11.

Further, the supply / discharge pump mechanism 2 for circulating the pure water W and the sample S through the test liquid supply / discharge path P has a dilution pump 21 arranged in the pure water flow path P _W and a discharge path P _out.
Of the dilution pump 21 and the discharge pump 22. The flow rates F _W and F _M of the dilution pump 21 and the discharge pump 22 are controlled by the control means 5 which will be described later according to the output T from the transmitted light amount measuring unit 1. I'm trying to be controlled. The discharge pump 22 has at least the sample flow path P _S and the pure water flow path P _W.
As long as it is arranged on the downstream side of the confluence point with (that is, between the supply path P _in and the measurement cell 11 or between the measurement cell 11 and the discharge path P _out as shown in the drawing), the test object described later It is possible to adjust the dilution ratio of the sample S in the liquid M.

In the coloring degree measuring apparatus having the above-mentioned structure, the sample dilution ratio D of the sample liquid M in the measuring cell 11 is adjusted by adjusting the flow rate Fw of the dilution pump 21 to the flow rate F of the discharge pump 22. the flow rate Fw in the range smaller than _M, F _M
It is made by adjusting at least one of the above.

That is, the flow rate Fw of the dilution pump 21.
Is smaller than the flow rate F _M of the discharge pump 22, pure water W is supplied to the measuring cell 11 at the flow rate Fw, and the sample S has a flow rate difference Δ obtained by subtracting the flow rate Fw from the flow rate F _M.
F (= F _S ), so that the test liquid M in the measurement cell 11 is mixed with the pure water W and the sample S at a rate equal to the ratio of the flow rate F _W and the flow rate F _S. become. Accordingly, the dilution ratio D of the sample S in the test liquid M is a value obtained by dividing the pump flow rate F _W by the flow rate F _S of the sample S. Therefore, when the dilution ratio D is represented by the flow rates F _W and F _M , the following formula is obtained.
It is expressed as a two-variable function by the flow rates F _W and F _M as shown in (A). For example, while the flow rate F _M of the discharge pump 22 is kept constant, the flow rate F _W of the dilution pump 21 is changed to produce the above dilution ratio. D can be adjusted to any value.

[0046] _{D = F W / (F M} -F W) ... (A) the sample S using the configured colored measuring apparatus as described above
The following procedure can be adopted to measure the degree of coloring.

That is, first, based on the output from the flow rate control unit 31 in the control means 3, the dilution pump 21 is
Pump flow F _W of the pump flow rate P _M of the discharge pump 22 is controlled to be equal (this time flow differential [Delta] F =
F _M -F _W = 0). In this state, the sample S does not flow through the sample flow path P _S , and the light from the light source 12 passes through the measurement cell 11 filled with the test liquid M composed of only pure water W and the photodetector 13 And the output T _{0 of the} photodetector 13 at this time is used as a reference.

The flow rate difference ΔF may be set to be not zero but smaller than zero so that the pure water W is surely introduced into the measuring cell 11. In this case, the overflow of the pure water W flows back through the sample flow path Ps, but if it is prevented from mixing with the sample S, the measurement will not be hindered, but rather the sample flow path Ps. There is an advantage that cleaning is performed.

Next, the pump flow rate of the discharge pump 22.
F_MWhile maintaining a constant value, the pump of the dilution pump 21
Flow rate F_WIs gradually decreased, the flow rate difference ΔF, that is, the sample flow
Road P _SFlow rate of the sample S supplied to the measuring cell 11 through
F_SIs gradually increased, the transmitted light amount of the test liquid M is
The output T of the photodetector 13 at this time₁Is above
Output T as a reference₀Lower.

Eventually, the displacement Δ between the outputs T ₀ and T ₁
When t reaches a preset reference value Ta as will be described later, the dilution rate calculator 32 performs a calculation for substituting the pump flow rates F _W and F _M at that time into the formula (A). The display unit 4 immediately displays the dilution ratio D of the sample S in the test liquid M calculated as the coloring degree.

In the first measuring method, the reference value Ta
Is a standard for immediately adopting the dilution ratio D of the sample S in the test liquid M as the coloring degree, and if the level of the reference value Ta is inappropriate, the coloring degree calculated by the conventional sensory dilution method The error between and becomes too large. That is, when the reference value Ta is lower than an appropriate value, a value higher than the coloring degree calculated by the conventional dilution method by sensory measurement is displayed for the same sample S, and when it is too high, a low value is displayed. Will be displayed.

Therefore, in order to match the degree of coloring obtained by the above-mentioned measuring method with the degree of coloring obtained by the above-mentioned sensory dilution method, it is impossible to distinguish it from pure water by the visual observation of the monitor in the above-mentioned sensory dilution method. A sample having a known dilution ratio, which is certified as, is accommodated in the measurement cell 11, and the output of the photodetection element 13 at this time is used as a reference to make the inductive determination.

As described above, according to this measuring method, the judgment as to whether or not the sample diluted with a predetermined dilution ratio and pure water can be discriminated is replaced by the visual observation of the monitor in the dilution method by the sensory measurement method. , Can be performed based on the output of the photodetection element 13. As a result, similar to the dilution method by the sensory measurement method, it is possible to compare the degree of coloring between the samples having different hues and saturations, and the obtained degree of coloring is the same as that of the sample S at the same dilution ratio. It shows that coloring becomes invisible by diluting, and it has an advantage that it is easy to intuitively grasp the degree of coloring. Moreover, it also has the advantage of the instrumental measurement method that is excellent in the reproducibility and stability of the obtained coloring degree.

The photo-detecting element 13 in this embodiment is a sensor for determining whether or not the pure water W and the test liquid M can be discriminated instead of the visual sense in the sensory measurement method as described above. Therefore, an element having a sensitivity characteristic as close as possible to the visual sense is used.

That is, FIG. 3 is a graph showing the spectral sensitivity characteristics of the photodetector used in the above embodiment,
As shown in the figure, the photodetector element 13 is 400 in the visible section.
It has a sensitivity region of up to 700 nm and has sensitivity characteristics represented by a spectral sensitivity curve C that approximates the standard relative luminous efficiency curve C _E having a peak at a wavelength of 560 nm. Also produces an output similar to the visual one,
It is possible to obtain a value close to the coloring degree calculated by the dilution method by the sensory measurement method without any correction.

Further, it is obvious that it is not appropriate to use a single wavelength light source as the light source 12, as shown in FIG.
As shown in, a daylight white fluorescent lamp having a characteristic represented by a spectral distribution curve C _L that maintains a predetermined level over the entire visible wavelength range, such as the spectral distribution curve C _S of sunlight, is used.

Further, in the configuration shown in FIG. 1 in which the degree of coloration is measured by the above-mentioned measuring method, the transmitted light amount measuring unit 1 (at the downstream side of the point where the sample flow path P _S and the pure water flow path P _W meet). Since the test solution M or the pure water W having an extremely large dilution ratio flows through the measuring cell 11) instead of the stock solution of the sample S, the factors such as the contamination of the measuring cell 11 without maintenance for a relatively long time. Therefore, the measurement accuracy does not decrease.

Since only the pure water W flows through the dilution pump 21 and the test liquid M having a very large dilution ratio and almost close to the pure water W flows through the discharge pump 22, the pumps 21 and 22 are hardly soiled.

In addition, in the above-described structure, by operating only the dilution pump 21 while stopping the discharge pump 22, the pure water W flows through the sample flow path P _S in the direction opposite to the so-called "backwashing". The sample flow path P _S can also be cleaned by this, and there is also an advantage that the maintenance of the coloring degree measuring device becomes easier.

FIG. 2 is a block diagram of another embodiment of the coloring degree measuring apparatus according to the present invention. In this embodiment, a control cell 14 and a photodetecting element 15 corresponding thereto are added to the transmitted light amount measuring unit 1 in the coloring degree measuring apparatus shown in FIG.

The control cell 14 is formed in the pure water flow path Pw and is arranged at a position where light from the light source 12 common to the measurement cell 11 is irradiated, and the photodetection element 15 is provided in the control cell 14. The amount of light that passes through will be detected.

Therefore, the dilution pump 21 and the discharge pump 22
The flow rate difference ΔF with
Only the pure water W will be filled in the rule 14,
The output of the detection element 15 is measured by the device based on FIG.
Output T that is the standard in the law ₀Will be equivalent to.

Therefore, when the measurement is performed using the apparatus having the configuration shown in FIG. 2, the photodetector element 1 corresponding to the measurement cell 11 is used.
The output of 3 and the output of the photodetector 15 are compared at the same time,
When the difference Δt between the outputs of the two photodetector elements 13 and 15 reaches a predetermined reference value Ta, the dilution pump 21.
The dilution ratio D of the sample S in the test liquid M can be calculated based on the flow rate difference ΔF ₁ between the discharge pumps 22.

As a result, it becomes unnecessary to greatly change the flow rate of either the dilution pump 21 or the discharge pump 22 in order to control the flow rate difference ΔF, and the purity of the pure water W is lowered, so that it is extremely colored. It is possible to guarantee the measurement accuracy even if there is a variation such as a change, and it is possible to measure the coloring degree of the sample S at an extremely short time interval.

[0065]

As described above, according to the present invention, the dilution ratio of the sample in the test liquid in the measurement cell can be adjusted based on the difference in flow rate between the dilution pump and the discharge pump, whereby the coloring by the dilution method can be performed. The degree can be easily calculated.

Moreover, even though the water quality control can be automated, it has the advantage that the dilution method among the sensory measurement methods is adopted to the maximum, and the maintenance is easy.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of an apparatus according to the present invention.

FIG. 2 is a configuration diagram of another embodiment of the device according to the present invention.

FIG. 3 is a sensitivity characteristic diagram of a photodetector.

FIG. 4 is a spectral distribution characteristic diagram of a light source.

[Explanation of symbols]

1 the flow rate of the transmitted light quantity measurement unit 2 supply and discharge pump mechanism 3 control unit 11 measuring cell 12 light source 13 light-detecting element 14 controls the cell 15 light-detecting element 21 dilution pump 22 discharge pump 31 flow rate control unit 32 dilution magnification calculator F _M discharge pump F _W Dilution pump flow rate D Dilution ratio M Test liquid P Test liquid supply / discharge path P _S Sample flow path P _W Pure water flow path P _in Supply path P _out Discharge path S Sample T ₀ , T ₁ , T ₁₀ , T ₂₀ Photodetector output Ta Reference value Tb Predetermined value W Pure water ΔF Flow rate difference Δt Output displacement

─────────────────────────────────────────────────── ───Continued from the front page (56) References JP-A-2-272361 (JP, A) JP-A-2-248844 (JP, A) Fukukaihei 6-86056 (JP, U) Registered utility model 3005439 ( JP, U) Yasuhiko Miyoshi et al., Characteristics and Problems of Coloring Measurement Method of Wastewater, Tokyo Metropolitan Institute of Environmental Science 1991-2, Japan, December 16, 1991, PAGE. 162-169 (58) Fields surveyed (Int.Cl. ⁷ , DB name) G01N 21/00-21/61 G01N 1/10 G01N 33/18 JISST file (JOIS)

Claims (2)

(57) [Claims] 1. A test liquid prepared by diluting a sample (S) with pure water (W).
(M) and the dilution so that the degree of coloring of the sample (S) is measured based on the amount of transmitted light of the sample solution (M) and the dilution ratio of the sample (S) in the sample solution (M). A coloring degree measuring apparatus by the method, comprising a measuring cell (11) containing the test liquid (M), the measuring cell (1)
In the measurement cell (11), a transmitted light quantity measuring unit (1) composed of a light source (12) for irradiating light to 1) and a light detection element (13) for detecting the transmitted light quantity of the measurement cell (11) Alternatively, a sample flow path (Ps) and a pure water flow path that are independent of each other at a predetermined location on the upstream side of the measurement cell (11).
A supply path (Pin) that merges with (Pw) and a discharge path (Pout) that discharges the test liquid (M) on the downstream side of the measurement cell (11).
And a dilution pump (21) disposed in the pure water flow path (Pw) and at least the sample flow path (P) of the test liquid supply / discharge path (P). Ps) and pure water flow path (Pw) supply and discharge pump mechanism composed of a drainage pump (22) arranged at a predetermined position downstream from the junction
(2) and provided with, the transmitted light quantity measurement unit (1), is formed in the pure water passage (Pw)
The light from the light source (12) common to the measuring cell (11) is emitted.
The target cell (14) arranged as described above and the target cell (1
A coloring degree measuring device by a dilution method , which comprises a photodetector (15) for detecting the amount of transmitted light of 4) . 2. A structure in which the spectral sensitivity characteristics of the photodetector elements (13), (15) are approximated to the standard relative luminous efficiency characteristics.
A coloring degree measuring device according to the dilution method described in 1 .