JP2010181150A - Method and instrument for measuring concentration of dissolved substance, and method and device for detecting color tone - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for measuring the concentration of a dissolved substance for achieving the miniaturization of a measuring instrument for measuring the concentration of the dissolved substance and also reducing the amount of a reagent or sample, in measuring the concentration of the dissolved substance in the sample on the basis of the transmittance or absorbance of light. <P>SOLUTION: In the method for measuring the concentration of the dissolved substance, light is transmitted through a solution S1 to be measured or the like developed in color by the addition of the reagent to the sample to measure the concentration of the dissolved substance in the sample on the basis of the transmittance or absorbance of light. The light from a luminous body 31 transmitted through the solution S1 to be measured is reflected by the reflecting plate 21 placed in opposed relation to the luminous body 31 so as to hold the solution S1 to be measured and the reflected light from the reflecting plate is again transmitted through the solution S1 to be measured to be received by the light receiving body 32 provided on the side of the luminous body 31. Since the light is reciprocally transmitted through the solution S1 to be measured, the passing distance of the light passed through the solution S1 to be measured is made twice or more the usual passing distance of the light and the absorption quantity of the light by the solution S1 to be measured is increased according to the passing distance made twice or more of the light. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a lysate concentration measuring method and a measuring apparatus for measuring a lysate concentration in a sample based on light transmittance or absorbance. The present invention also relates to a color tone detection method and a detection apparatus for detecting the color tone of the liquid to be detected based on the light absorbing action of the liquid to be detected.

  In many cases, the concentration of the dissolved substance dissolved in the liquid is determined by absorptiometry. In this absorptiometric method, for example, a reagent is added to a sample having a lysate, and the sample is colored to form a liquid to be measured, and then the liquid to be measured is accommodated in a transparent measurement cell. Next, the liquid to be measured is allowed to transmit a specific wavelength of light having a high degree of absorption from the illuminant through the measurement cell, and a part of the light is absorbed by the liquid to be measured. The light is received by the photoreceptor, and the transmitted light intensity at this time is measured. Subsequently, by obtaining the absorbance (or transmittance) from the transmitted light intensity measured at this time and the transmitted light intensity of light having a specific wavelength with respect to the transparent liquid measured separately, for example, a sample having a known concentration in advance with respect to this lysate. Using the calibration graph showing the relationship between the absorbance (or transmittance) and the lysate concentration created by the above, the lysate concentration in the sample is determined.

  In this case, if the change in absorbance (or transmittance) is large with respect to the change in lysate concentration, and the slope of the calibration graph showing these relationships is large, the lysate concentration in the solution to be measured should be obtained with high accuracy. Can do.

  Here, when measuring the dissolved substance concentration in the liquid to be measured, as described in Patent Document 1, generally, the light emitter and the light receiver sandwich a measurement cell containing the liquid to be measured. Opposed to each other.

JP 2006-257553 A

  By the way, the amount of light absorbed by the liquid to be measured is determined by the passing distance of the light passing through the liquid to be measured, and increases as the passing distance increases. When the amount of absorbed light increases, the amount of light transmitted per concentration of the lysate decreases, and the change in transmittance (or absorbance) increases with changes in the lysate concentration. Therefore, in the conventional method for measuring the concentration of dissolved matter in the liquid to be measured, the width size of the liquid to be measured in the measurement cell arranged between the light emitter and the light receiver must be increased.

  For this reason, in the conventional measuring method and measuring apparatus, due to the increase in the size of the measuring cell, there is a problem that the apparatus is increased in size and the amount of reagents and samples is increased.

  On the other hand, even when detecting the color tone of the liquid to be detected based on the light absorbing action by applying light from the light emitter to the liquid to be detected and measuring the transmitted light intensity from the liquid to be detected by the light receiver. The same problem as when measuring the lysate concentration occurs.

  In view of the above points, the present invention can achieve downsizing of the apparatus and reduce the amount of reagent and sample when measuring the concentration of a lysate in a sample based on light transmittance or absorbance. An object of the present invention is to provide a method and an apparatus for measuring the concentration of a lysate. In addition, the present invention can detect a color tone that can reduce the size of the apparatus and reduce the amount of the sample when detecting the color tone of the liquid to be detected based on the light absorption effect of the liquid to be detected. It is an object to provide a method and a detection device.

  According to the first aspect of the present invention, light is transmitted through a measurement liquid that is colored by addition of a reagent to the sample or a sample that is colored by the concentration of a lysate. A lysate concentration measurement method for measuring a concentration of a lysate in the sample based on absorbance, wherein light from a light emitter that has passed through the solution to be measured is sandwiched between the solution to be measured. The light is reflected by a reflector placed facing the light emitter, and the reflected light is transmitted again into the liquid to be measured, and then received by a light receiver on the light emitter side.

  In this invention, the light emitted from the light emitter toward the liquid to be measured passes through the liquid to be measured while a part of the light is absorbed by the liquid to be measured, and is reflected on the opposite side of the light emitter. The light is reflected by the plate, and part of the light is again absorbed by the liquid to be measured, passes through the liquid to be measured, and is received by the light receiver on the light emitter side. That is, in the present invention, since the light from the light emitter is transmitted so as to reciprocate in the liquid to be measured, the distance of the light passing through the liquid to be measured can be more than twice the normal distance. The amount of light absorbed by the measurement liquid can be increased accordingly. Of course, in the present invention, since it is necessary to calculate the light absorbance of the liquid to be measured, the light receiver measures the transmitted light intensity of the light emitted from the light emitter to the liquid to be measured and absorbs the light by the liquid to be measured. Is measured (for example, when a transparent liquid is used instead of the liquid to be measured), the transmitted light intensity of the light from the illuminant is also measured. Calculated. And the density | concentration of the lysate in a sample is computed from the relationship between the lysate density | concentration produced in advance, the light absorbency, etc. FIG.

  According to a second aspect of the present invention, in the case of the first aspect of the invention, the light emitter emits light including a visible light range, and the light receiver transmits the light to be measured. Of the light from the body, the light of the red region component, the light of the green region component, and the light of the blue region component, which are obtained by substantially dividing the light in the visible light region into three parts, or receive these And receiving light of a plurality of color region components combined with each other.

  In the present invention, the light receiver is obtained by substantially dividing the wavelength band of light in the visible light region out of the light from the light emitter transmitted through the liquid to be measured, and is obtained by dividing the light of the red region component and the light of the green region component. And blue region component light are received, and the intensity of the light is measured. For this reason, for example, when the solution to be measured turns yellow due to the lysate due to the addition of a reagent, the light intensity of blue, that is, the blue region component, which is a complementary color of yellow, is measured by the photoreceptor. By calculating the absorbance of the lysate, the concentration of dissolved matter in the liquid to be measured can be easily obtained.

  Further, in the present invention, the light receiver is obtained by substantially dividing the wavelength band of light in the visible light region out of the light from the light emitter that has passed through the liquid to be measured, and the light of the red region component and the green region component. The light of a plurality of color region components, which is a combination of the light of the blue region component and the light of the blue region component, is received, and the intensity of each light is measured. For this reason, for example, when the color of the liquid to be measured changes from the red complementary color to the blue complementary color depending on the concentration of the dissolved matter, the light of the red region component and the blue region component are changed by the photoreceptor. By measuring the intensity of light and calculating the absorbance of the light and the like, the concentration of dissolved matter in the liquid to be measured can be easily obtained. Of course, when the color of the liquid to be measured is not simple, or when the color of the liquid to be measured varies depending on the concentration of the dissolved matter, the light of the red region component, the light of the green region component, and the blue region are affected by the photoreceptor. All of the component lights are received, and the absorbances of the light of the three region components are calculated to determine the concentration of the dissolved matter in the liquid to be measured.

  According to a third aspect of the present invention, in the case of the first or second aspect, the color of the reflecting surface of the reflecting plate is white.

  According to a fourth aspect of the present invention, the transmittance of light is obtained by transmitting light to a liquid to be measured that is colored by the addition of a reagent to the sample or a sample that is colored by a dissolved material. Alternatively, it is a lysate concentration measuring device that measures the concentration of the lysate in the sample based on absorbance, and a light emitter that transmits light in the liquid to be measured and the liquid to be measured are sandwiched between them. A reflecting plate placed opposite to the light emitter and reflecting light from the light emitter transmitted through the liquid to be measured; and disposed on the same side as the light emitter with respect to the liquid to be measured; And a light receiving body for receiving light from the light emitting body reflected by the plate and transmitted again through the liquid to be measured.

  The invention according to claim 5 of the present invention is a color tone detection method for detecting the color tone of the liquid to be detected by receiving light from a light emitter that has passed through the liquid to be detected by a light receiver. The light from the light emitter that has passed through the liquid to be detected is reflected by a reflecting plate placed opposite the light emitter so as to sandwich the liquid to be detected, and this reflected light is reflected by the light to be detected. After being transmitted again in the liquid, it is received by the light receiver on the light emitter side, and the light emitter emits light including a visible light region, and the light receiver transmits the liquid to be detected. Of the light from the illuminant, the intensities of the light of the red region component, the light of the green region component, and the light of the blue region component, which are obtained by substantially dividing the light in the visible light region into three parts, are measured. It is characterized by that.

  In the present invention, the light receiver is obtained by substantially dividing the wavelength band of light in the visible light region out of the light from the light emitter that has passed through the liquid to be detected, and the light of the red region component and the light of the green region component. And the light of the blue region component are separately received and the intensity of each light is measured, so using the light intensities of these three color region components considered to correspond to the three primary colors of light, The color tone of the liquid to be detected can be easily obtained by the light absorbing action of the liquid to be detected. In this case, since the light from the illuminant is transmitted so as to reciprocate in the liquid to be detected, the passing distance of the light passing through the liquid to be detected is more than twice as long as the normal light. The amount of absorption increases. For example, the light from the light emitter that passes through the transparent liquid is received by the light receiver, and the transmitted light intensity close to 100% is also measured. The transmittance may be calculated, and the color tone of the liquid to be detected may be detected based on the absorbance and transmittance.

  According to a sixth aspect of the present invention, in the case of the fifth aspect, the color of the reflecting surface of the reflecting plate is white.

  The invention according to claim 7 of the present invention is a color tone detection device for detecting the color tone of the liquid to be detected by receiving light from a light emitter that has passed through the liquid to be detected by a light receiver. A light emitter that transmits light in the liquid to be detected and a light emitter that is placed opposite the light emitter so as to sandwich the liquid to be detected, and reflects light from the light emitter that has passed through the liquid to be detected. A light receiving body that receives light from the light emitting body that is disposed on the same side as the light emitting body with respect to the liquid to be detected, is reflected by the light reflecting plate, and is transmitted again through the liquid to be detected; And the light emitter emits light including a visible light region, and the light receiver substantially omits light in the visible light region out of light from the light emitter transmitted through the liquid to be detected. Red region component light, green region component light, and blue obtained by dividing into three parts Characterized in that it includes a filter for measuring frequency components of the light, the respective intensities.

  According to the first and fourth aspects of the present invention, the light from the illuminant is transmitted so as to reciprocate through the liquid to be measured, and the light passing distance through the liquid to be measured is set to a normal distance. Since it can be more than twice, the width size of the liquid to be measured between the light emitter or the light receiver and the reflector, that is, the width size of the measurement cell holding the liquid to be measured can be reduced, and the apparatus can be made compact. Since the flow area of the liquid to be measured in the measurement cell can be reduced, the amount of the sample serving as the liquid to be measured and the amount of necessary reagents can be reduced. Further, according to the present invention, unlike the prior art, it is not necessary to arrange the light emitter and the light receiver so as to face each other via the liquid to be measured, and the light emitter and the light receiver can be disposed on the same side. The optical axis of the light emitter and the light receiver can be easily aligned, and the light emitter and the light receiver can be integrated. For this reason, in this invention, while being able to measure a density | concentration easily, manufacture of a measuring apparatus can also be made easy.

  According to the invention described in claim 2 of the present invention, it is sufficient to have a simple pair of a light emitter and a light receiver for measuring the concentration of any lysate. There is no need to use multiple sets of illuminants or photoreceptors when using different types of illuminants or measuring lysate concentrations that change color depending on the concentration. Miniaturization can be achieved. For this reason, the mutual interference of the light which arises when using several light-emitting body simultaneously is not produced. In addition, according to the present invention, the light emitter need only emit light including a visible light range, and it is not necessary to emit only light of a specific wavelength unlike the conventional one. It is difficult to be affected by wavelength variations among lots and changes in output over time, and can always perform highly accurate measurements.

  According to the third aspect of the present invention, since the reflecting surface does not absorb only light of a specific wavelength, the influence of reflection can be kept small.

  According to the fifth and seventh aspects of the present invention, no matter what the color tone of the liquid to be detected is, it is only necessary to have a pair of light emitter and light receiver for detecting the color tone. Because there is no need to use multiple sets of light emitters or photoreceptors depending on the number of color tones, or to detect color tones that cause color changes, it is not necessary to use multiple sets of light emitters or photoreceptors. Can be miniaturized. For this reason, the mutual interference of the light which arises when using several light-emitting body simultaneously is not produced. In addition, according to the present invention, the light emitter need only emit light including a visible light range, and it is not necessary to emit only light of a specific wavelength. Therefore, variation in wavelength depending on the product lot of the light emitter (for example, LED). In addition, it is difficult to be affected by changes in output with time, and it is possible to always detect a color tone with high accuracy.

  Furthermore, according to the present invention, the light from the illuminant is transmitted so as to reciprocate in the liquid to be detected, so that the distance of the light passing through the liquid to be detected can be more than twice the normal distance. In addition, the width size of the liquid to be detected between the light emitter and the light receiver and the reflector, that is, the width size of the measurement cell holding the liquid to be detected can be reduced, and the detection device can be miniaturized. Since the flow channel area of the liquid to be detected in the measurement cell can be reduced, the amount of the sample that becomes the liquid to be detected can also be reduced.

  According to the sixth aspect of the present invention, since the reflecting surface does not absorb only light of a specific wavelength, it is possible to suppress the influence of reflection.

It is a disassembled perspective view of the density | concentration measuring apparatus which concerns on one embodiment of this invention. It is operation | movement explanatory drawing of a density | concentration measuring apparatus. It is an electrical wiring diagram in a light receiving / emitting part. It is explanatory drawing of another density | concentration measuring apparatus. It is a figure which shows the measured value of the light absorbency with respect to the phosphate ion concentration when using the concentration measuring device and when using the spectrophotometer, and (a) summarizes the phosphate ion concentration and the absorbance value in a table. (B) is a graph showing the relationship between phosphate ion concentration and absorbance. It is a figure showing the measured value of absorbance with respect to calcium hardness when using a concentration measuring device and when using a spectrophotometer, (a) is a table summarizing the values of calcium hardness and absorbance, (B) is a graph showing the relationship between calcium hardness and absorbance.

Embodiments of the present invention will be described below with reference to the drawings.
Embodiment 1
FIG. 1 shows a main part of a concentration measuring apparatus according to an embodiment of the present invention, and FIG. 2 is an explanatory view of the operation of the concentration measuring apparatus.

  The concentration measuring apparatus 1 can be used to easily calculate the concentration of a dissolved material such as dissolved oxygen, phosphoric acid, alkalinity component, hardness component, and silica dissolved in industrial water or domestic water by using absorbance or light transmittance. Measure. As shown in FIG. 1, the concentration measuring apparatus 1 is attached to a measurement unit 2 in which a detection target liquid S1 and an adjustment liquid S0 are flowed, and one side surface of the measurement unit 2, and emits light toward the measurement unit 2 side. Receiving and emitting unit 3 for receiving reflected light from measuring unit 2, liquid supply line 4 for supplying detected liquid S1 and adjustment liquid S0 to measuring unit 2, and detected liquid S1 from measuring unit 2 A liquid discharge line 5 for discharging the adjustment liquid S0 and an arithmetic processing unit 6 (see FIG. 3) to which an output from the light emitting / receiving unit 3 is input. The liquid supply line 4 is provided with a tube pump 40 and a strainer 41.

  As shown in FIG. 1 and FIG. 2, the measurement unit 2 is a box having a small left and right width, and a left side surface portion is formed from a white reflection plate 21 having a thickness t1 = 2 mm, and faces the reflection plate 21. The right inner surface black side 22 is also formed of a plate material having a thickness t2 = 2 mm. In the center of the right side 22 is a rectangular acrylic product having a height H of 18 mm and a width W of 8 mm. A transparent portion 23 is formed. The front surface portion, the rear surface portion, the upper surface portion, and the lower surface portion of the measurement unit 2 are formed of a black plate material having a predetermined thickness and the inner surface, and the liquid supply line 4 is connected to the lower surface portion, A liquid discharge line 5 is connected. The left-right width size of the inner surface of the measuring unit 2, that is, the left-right width size T of the flow path of the liquid S1 to be measured is set to 6 mm. The measuring unit 2 has a transparent portion 23, a rectangular flow path portion of the liquid S1 to be measured and a rectangular portion of the reflecting plate 21 projected on the reflecting plate 21 side, and a capacity of 0.7 mL. The measurement cell G is formed. In addition, the left-right width size T of the inner surface of the measurement unit 2 can be changed according to the shape and performance of the light emitter 31 and the light receiver 32, and the dissolved substance concentration.

  The light receiving / emitting unit 3 is a casing 30 in which an opening 30a is provided on the measurement unit 2 side. The light emitting unit 31, the light receiving unit 32, a wiring board, and the like are housed. It is provided so as to protrude from the casing 30. The illuminator 31 emits light into the measurement cell G and transmits this light into the measured liquid S1 and the adjustment liquid S0. For the light emitter 31, a light source such as a light emitting diode (LED) that emits light (white light) including a visible light region is used.

  The light receiving body 32 receives the transmitted light of the light emitted from the light emitting body 31 from the measured liquid S1 and the adjustment liquid S0, and measures the transmitted light intensity of these transmitted light. The light receiving body 32 is obtained by dividing a wavelength band of light in the visible light region into three substantially by three photodiodes, light of a red region component (hereinafter referred to as red band light), and light of a green region component (hereinafter green). Three color filters F that transmit only the light of the blue band component (hereinafter referred to as blue band light), that is, the red (R) filter, the green (G) filter, and the blue (B) filter. Have. That is, an RGB color sensor having a photodiode D1 having an R filter, a photodiode D2 having a G filter, and a photodiode D3 having a B filter is used for the photoreceptor 32 ( 3), the light intensity of each of the red band light, the green band light, and the blue band light transmitted through each filter is simultaneously measured by the light receiving body 32. The The R filter transmits most red light in the red band light, the G filter transmits most green light in the green band light, and the B filter transmits blue light most in the blue band light.

  In addition, the light receiving body 32 is arranged on the same side as the light emitting body 31 with respect to the measurement cell G as shown in FIGS. For this reason, in the light receiving body 32, the transmitted light in the measured liquid S1 emitted from the light emitting body 31 is reflected by the reflecting plate 21 facing the light emitting body 31 with the measured liquid S1 in between, and the measured liquid S1 is in the measured liquid S1. The transmitted light when the light is transmitted again is received. In this case, as shown in FIG. 2, the light emitter 31 and the light receiver 32 are oriented so that the optical axis K1 of the light emitter 31 forms α = approximately 45 degrees with respect to the reflection plate 21. The optical axis K2 of the body 32 is directed so as to be orthogonal to the reflecting plate 21, and the intersection P between the reflecting plate 21 of the optical axis K1 of the light emitter 31 and the reflecting plate 21 of the optical axis of the light receiving body 32 Positioning is performed so that the intersection point substantially coincides with the intersection point. Therefore, the main light from the light emitter 31 that is reflected by the reflector 21 does not reach the light receiver 32, and the light receiver 32 is a part of the reflected light from the ambient light around the main light from the light emitter 31. And part of the light irregularly reflected by the reflector 21 is received.

  FIG. 3 is a circuit diagram in the measurement unit 2. In the figure, reference sign D1 is a photodiode having an R filter, reference sign D2 is a photodiode having a G filter, reference sign D3 is a photodiode having a B filter, and these are integrated. Thus, the photoreceptor 32 is formed. Further, in the figure, symbol L is a light emitting diode (LED) that becomes the light emitter 31, symbols C1, C2, and C3 are main circuits for the respective photodiodes D1, D2, and D3, and symbols O1, O2, and so on. O3 is an operational amplifier (operational amplifier) for each of the photodiodes D1, D2, and D3. The signal of the transmitted light intensity of each band light output from the photoreceptor 32 is transmitted to the arithmetic processing unit 6 through the operational amplifiers O1, O2, and O3.

  The arithmetic processing unit 6 calculates the time average intensity for each band light based on the intensity signals of the light of the red band light, the green band light, and the blue band light output from the photoreceptor 32, or the specific color is Using the transmitted light intensity of absorbed light and the transmitted light intensity of non-absorbed light, the absorbance and transmittance of red band light, green band light and blue band light can be calculated, or red band light and green light can be calculated. It has a calculation unit that calculates the concentration of lysate from each absorbance and transmittance of band light and blue band light, and for each type of lysate, each absorbance of red band light, green band light, and blue band light It has a memory | storage part which memorize | stores the table | surface etc. which show the relationship between the transmittance | permeability and a melt | dissolution density | concentration, and a display part which displays a melt | dissolution density | concentration.

Next, a procedure for measuring the concentration of dissolved matter (for example, phosphate ions) in the sample using the concentration measuring apparatus 1 will be described.
First, after adding a fixed amount (for example, 4 mL) of a reagent (a mixture of ammonium molybdate and astellic acid) to a fixed amount (40 mL) of a sample dissolved in trisodium phosphate (Na ₃ PO ₄ ), The solution to be measured S1 is made by allowing the sample to stand for about 15 minutes at 20 to 40 ° C. and causing sufficient color development. In this case, the color of the liquid S1 to be measured varies depending on the concentration of the dissolved substance (phosphate ion).

  Subsequently, a transparent adjustment liquid S0 (for example, pure water or a transparent sample before color development) that does not absorb light is measured from the liquid supply line 4 using a tube pump 40 (for example, SMP21 manufactured by EYELA). After passing water through the part 2 at a flow rate of 10 mL / min for about 3 minutes, the water flow was stopped and light from the light emitter 31 was passed through the transparent part 23 of the measuring cell G for 1 minute. Irradiate (fire) during S1. As a result, the light including the visible light region from the light emitter 31 passes through the liquid to be measured S1 and is reflected by the reflecting plate 21, and then passes through the liquid to be measured S1 again and is received by the light receiver 32. Is done. In this case, the light receiving body 32 receives the transmitted light of the measured liquid S1 from the light emitting body 31 via the three color filters F of RGB, so that the light receiving body 32 has a wavelength band of light in the visible light range. The intensity of each of the red band light, the green band light, and the blue band light divided into approximately three is measured simultaneously. Then, the arithmetic processing unit 6 averages the output values from the photoreceptor 32 over one minute, and the red band light and the green band light when there is no light absorption by the liquid S1 to be measured (transmittance 100%). The average light intensity of each blue band light is calculated.

  Next, a reagent is added and allowed to stand for a certain period of time, and a sufficiently colored liquid S1 to be measured is passed through the measuring section 2 (measuring cell G) at a flow rate of 10 mL / min for 3 minutes as in the case of the adjusting liquid S0. Water is passed to stop water flow, and then light from the light emitter 31 is transmitted through the liquid S1 to be measured and received by the light receiver 32 for 1 minute. The light receiving body 32 measures the intensity of each of the red band light, the green band light, and the blue band light that has been partially absorbed by the liquid S1 to be measured. The arithmetic processing unit 6 averages the output values from the photoreceptor 32 over 1 minute, and each of the red band light, the green band light, and the blue band light in which a part of the light is absorbed by the liquid S1 to be measured. After calculating the average light intensity of the red band light, the average light intensity of each of the red band light, the green band light, and the blue band light measured using the adjustment liquid S0 having a transmittance of 100% is used. The respective absorbances (or transmittances) of the green band light and the blue band light are calculated. And the arithmetic processing unit 6 has memorize | stored about the specific melt | dissolution (phosphate ion), respectively the light absorbency (or transmittance | permeability) and the density | concentration of a melt | dissolution about red band light, green band light, and blue band light. From the relationship, the current concentration of the dissolved substance in the liquid S1 to be measured is calculated and displayed.

  Here, the liquid S1 to be measured shows, for example, a color depth proportional to the concentration of the dissolved matter, and absorbs the complementary color light of the colored light that has been developed at a rate proportional to this concentration. Therefore, the relationship between the respective absorbances (or transmittances) of the red band light, the green band light, and the blue band light transmitted through the measured liquid S1 and the concentration of the dissolved substance in the measured liquid S1 is obtained in advance. In this case, the concentration of the dissolved matter in the measured liquid S1 can be easily calculated from the absorbance (or transmittance) of the red band light, the green band light, and the blue band light transmitted through the measured liquid S1.

  When the liquid S1 to be measured is colored yellow, for example, by adding a reagent, the liquid S1 to be measured hardly absorbs red band light and green band light, and is blue band light that is complementary color light. Therefore, it is necessary to consider only the blue band light measured by the photodiode D3 provided with the B filter. Further, when the liquid S1 to be measured is colored blue, for example, the liquid S1 to be measured hardly absorbs blue band light and absorbs red band light and green band light. The intensity may be determined in consideration of the intensity of red band light and green band light measured by the photodiodes D1 and D2 including the R filter and the G filter.

  Further, the color of the liquid S1 to be measured may change gradually from a specific color to another color, for example, according to the concentration of the dissolved matter. Even in this case, the relationship between the respective absorbances (or transmittances) of the red band light, the green band light, and the blue band light transmitted through the measurement liquid S1 and the concentration of the dissolved substance in the measurement liquid S1 is previously determined. Therefore, the concentration of the dissolved substance in the measured liquid S1 can be easily calculated from the respective absorbances (or transmittances) of the red band light, the green band light, and the blue band light transmitted through the measured liquid S1. it can.

Next, the function and effect of a method for measuring the concentration of a dissolved substance in a sample using the concentration measuring device 1 (hereinafter referred to as a concentration measuring method) will be described.
In this concentration measurement method, the light emitted from the light emitter 31 toward the liquid S1 to be measured passes through the liquid S1 to be measured while a part of the light is absorbed by the liquid S1 to be measured, and then the light emitter. The light is reflected by the reflecting plate 21 on the opposite side of 31, and part of the light is again absorbed by the liquid S 1 to be measured, and passes through the liquid S 1 to be measured, and is incident on the light receiver 32 on the light emitter 31 side. Is received. That is, in this concentration measurement method, the light from the illuminant 31 is transmitted so as to reciprocate in the measured liquid S1, so that the passing distance of the light passing through the measured liquid S1 is more than twice the normal distance. And the amount of light absorbed by the liquid S1 to be measured can be increased accordingly.

  For this reason, in this concentration measurement method, the width size of the liquid S1 to be measured between the light emitter 31 or the light receiver 32 and the reflecting plate 21, that is, the width size T of the flow channel cross section of the measurement cell G can be reduced. As a result, the concentration measuring apparatus 1 can be reduced in size, and the cross section of the flow channel in the measurement cell G can be reduced, so that the amount of the sample for the liquid S1 to be measured and the amount of necessary reagents can be reduced. Further, according to this concentration measuring method, it is not necessary to arrange the light emitter 31 and the light receiver 32 so as to face each other via the liquid S1 to be measured as in the prior art, and the light emitter 31 and the light receiver 32 are arranged. Since they can be arranged on the same side, it is not necessary to align the optical axes of the light emitter 31 and the light receiver 32, and the light emitter 31 and the light receiver 32 can be easily manufactured so as to be integrated. For this reason, in this concentration measuring method, the concentration can be easily measured, and the concentration measuring apparatus 1 can be easily manufactured.

  Further, in this concentration measurement method, the light receiver 32 is obtained by dividing the wavelength band of light in the visible light region into approximately three parts of the light from the light emitter 31 that has passed through the liquid S1 to be measured. The green band light and the blue band light are received, the intensity of each light is measured, and thereby the absorbance (or transmittance) of these color band lights is calculated. For this reason, in this concentration measurement method, no matter what lysate concentration is measured (for example, the color of the liquid S1 to be measured is any color or the color of the liquid S1 to be measured is Even when the density changes from a specific color to another color), a simple pair of light emitters 31 and light receivers 32 is sufficient. For example, as in the past, light emission with different wavelengths for each type of dissolved material. It is not necessary to use multiple sets of light emitters and light receivers when using a body or measuring the concentration of a lysate that changes color depending on the concentration, so that measurement costs can be reduced and the measuring device can be downsized. . For this reason, the mutual interference of the light which arises when using several light-emitting body simultaneously is not produced.

  Furthermore, in this concentration measurement method, the light emitter 31 only needs to emit light including a visible light range, and it is not necessary to emit only light of a specific wavelength unlike the conventional one. It is difficult to be affected by variations in wavelength depending on product lots or changes in output with time, and this illuminant 31 can always be used for highly accurate measurements.

  Further, in this concentration measurement method, even if dirt or bubbles adhere to the light emitting / receiving portions of the light emitter 31 or the light receiver 32 to cause a light attenuation effect, the light emitter (specific identification) used in the conventional measurement method is used. It emits light of a wavelength) and is less susceptible to the influence of a light receiving body and does not cause trouble in measurement.

  Furthermore, in this density measurement method, the color of the reflecting surface of the reflecting plate 21 is white, so that the reflecting surface does not absorb only light of a specific wavelength, and the influence of light reflection can be kept small. Compared with the mirror surface, the reflection plate 21 can increase the diffusely reflected light reaching the light receiving body 32.

  In addition, when the color of the liquid S1 to be measured indicates only a red complementary color, a green complementary color, or a blue complementary color, the light receiving body 32 includes a photodiode D1 having an R filter and a G filter, respectively. Any one of the photodiode D2 and the photodiode D3 including the B filter may be provided. In addition, when the color of the liquid S1 to be measured indicates an intermediate color between the three complementary colors, the photoreceptor 32 includes a photodiode D1 having an R filter, a photodiode D2 having a G filter, and a photodiode D3 having a B filter. It is sufficient to have any two of them.

  Further, the photoreceptor 32 may be one using a CCD sensor or a CMOS sensor in addition to the RGB color sensor.

  Further, the above description regarding the concentration measuring method applies to the concentration measuring apparatus 1 as well.

  Further, as shown in FIG. 4, the liquid supply line 4 is provided with a constant flow valve 42 and an electromagnetic valve 43 together with a strainer 41, and these are used to supply the liquid S1 to be measured to the measurement cell G. Also good. As shown in FIG. 4, the reagent supply line 8 is provided in the measurement unit 2, and the reagent in the tank 81 is directly supplied to the measurement cell G using the pump 80, and the reagent and liquid supply line 4 is supplied. The sample to be measured may be stirred in the measurement cell G, and the measurement liquid S1 colored by the reagent may be produced in the measurement cell G.

  In the above description, the liquid S1 to be measured is colored according to the dissolved substance concentration by adding a reagent to the sample. However, the sample itself is colored by the dissolved substance, and the density of the sample is determined by the concentration of the dissolved substance. In this case, the sample itself becomes the liquid S1 to be measured, and it is not necessary to add a reagent.

  Further, the concentration measuring device 1 is used as, for example, a hardness sensor for measuring the water quality (calcium hardness) at the outlet of the water softener. When the calcium hardness is higher than a predetermined value, the water softener is switched or a chemical injection pump is used. May be operated to inject the chemical into the water softener outlet line.

Next, the density measurement result by this density measurement method and the density measurement result by the JIS analysis method using a spectrophotometer will be compared and described while showing specific measurement data.
[Measurement Example 1]
First, the measurement of phosphate ion concentration will be described.

  A sample prepared by dissolving 3 sodium phosphate in pure water and adjusting the phosphate ion concentration to 0, 1, 2, 3, 4, 5 mg / L was prepared. To this, molybdenum according to JIS 8224-1993 was prepared. Based on the blue (ascorbic acid reduction) absorptiometric method (the wavelength of the light source is 880 nm), a reagent is added, and this sample is colored to produce the measurement liquid S1. Subsequently, the absorbance of these liquids S1 to be measured was measured using a spectrophotometer (UV1700, manufactured by Shimadzu Corporation) based on JIS 8224-1993. In this case, as a reference, absorbance was also measured using light sources with wavelengths of 630 nm, 550 nm, and 470 nm corresponding to red light, green light, and blue light. Subsequently, the absorbance of these liquids S1 to be measured was measured for red band light, green band light, and blue band light by this concentration measurement method using the concentration measuring apparatus 1. In this case, each band light when the light from the light emitter 31 when the transparent sample before addition of the reagent is passed through the measurement cell G is reflected by the reflecting plate 21 and the reflected light is received by the light receiver 32 is reflected. The strength was set to 100% transmittance. The measurement regarding the transmittance of 100% may be performed only once for a plurality of concentrations of the lysate. However, in order to increase the measurement accuracy, it is preferable to perform the measurement for each concentration.

  FIG. 5 (a) shows the absorbance values for various phosphate ion concentrations measured by this concentration measurement method and a method using a spectrophotometer. FIG. 5B shows the absorbance and phosphoric acid for red band light measured by this concentration measurement method and light having wavelengths of 880 nm and 630 nm measured by a method using a spectrophotometer. The relationship with the ion concentration is shown in a graph.

  From FIG. 5A, in the method using the spectrophotometer, when the wavelength of the light source is 880 nm (infrared light), the change in absorbance is large with respect to the phosphate ion concentration, and one specific light source is used. When selecting, it turns out that it is preferable to select the light source whose wavelength is 880 nm. Further, from FIG. 5 (a), in this concentration measurement method, the change in absorbance with respect to the phosphate ion concentration is larger in the case of red band light than in the case of green band light or blue band light, and thus the specific measurement. It is understood that it is preferable to select red band light when selecting one of the band lights. Further, from FIG. 5B, even in the case of red band light or light having a wavelength of 630 nm, the change in absorbance with respect to the phosphate ion concentration is large (the slope of the graph is large), so even when these lights are used. It can be seen that there is no hindrance in the measurement of the phosphate ion concentration. In the case of red band light, it is considered that the change in absorbance is larger than that in the case of light having a wavelength of 630 nm due to the influence of light in a wavelength region longer than 630 nm.

[Measurement Example 2]
Next, measurement of calcium hardness will be described. The sample in which the calcium hardness component is dissolved develops color when a reagent (triethanolamine 80%, ethanol 20%, Eriochrome Black T 0.025%) is added, but the color is a hardness value (concentration). It depends on.

  Prepare samples prepared by dissolving calcium chloride dihydrate in pure water and adjusting the calcium hardness to 0, 2, 5, 10 mg CaCO3 / L, add 4 mg of reagent to 50 mg of these samples, and stir well -Color development is performed to make the liquid S1 to be measured. Next, the absorbance of these liquids S1 to be measured was measured with a spectrophotometer (UV1700 manufactured by Shimadzu Corporation) using light with wavelengths of 630 nm, 550 nm, and 470 nm. Subsequently, the absorbance of these liquids S1 to be measured was measured for red band light, green band light, and blue band light by this concentration measurement method using the concentration measuring apparatus 1. In this case, each band light when the light from the light emitter 31 when the transparent sample before addition of the reagent is passed through the measurement cell G is reflected by the reflecting plate 21 and the reflected light is received by the light receiver 32 is reflected. The strength was 100% transmittance.

    FIG. 6A shows the absorbance for various calcium hardnesses measured by this concentration measurement method and a method using a spectrophotometer, and FIG. 6B shows the concentration measurement method and the spectrophotometer. The graph shows the relationship between the absorbance measured by a method using a meter and the calcium hardness.

  From FIG. 6B, in the method using a spectrophotometer, in the case of light having a wavelength of 630 nm, the graph N1 changes so that the absorbance decreases with an increase in calcium hardness, and in the case of light having a wavelength of 550 nm. When the graph N2 changes so that the absorbance increases as the calcium hardness increases, and the calcium hardness exceeds a certain value, the graph N1 and the graph N2 intersect, and the absorbance of light having a wavelength of 550 nm is 630 nm. It turns out that it becomes larger than the light absorbency of. On the other hand, even in this concentration measurement method, regarding the absorbance graph, the graph M1 in the case of red band light can be brought closer to the graph N1, and the graph M2 in the case of green band light can be brought closer to the graph N2. If a calibration graph of absorbance relating to calcium hardness is prepared for red band light and green band light, the calcium concentration can be easily calculated from the respective absorbances of red band light and green band light. In addition, if a calibration graph showing the relationship between the value of (absorbance of red band light / absorbance of green band light) and calcium hardness is prepared, the ratio value of the absorbance of these band lights is obtained. The calcium hardness can be calculated easily.

Embodiment 2. FIG.
By the way, the concentration measuring apparatus 1 can also be used when detecting the color tone (hue) of the liquid S2 to be detected. Therefore, a method for detecting a color tone of the liquid S2 to be detected (hereinafter referred to as a color tone detection method) using the same color tone detection device 1A as the concentration measuring device 1 will be described below. In the color tone detection apparatus 1A, parts having the same functions as those of the density measurement apparatus 1 are denoted by the same reference numerals, and description thereof is omitted.

First, the difference between the color tone detection device 1A and the density measurement device 1 will be described.
Since the color tone detection device 1A needs to detect various color tones, the photoreceptor 32 includes, for example, a photodiode D1 having an R filter, a photodiode D2 having a G filter, and a B filter. It is necessary to have three photodiodes D3. Further, the arithmetic processing unit 6A of the color tone detection device 1A has a table showing the relationship between the absorbance and transmittance of the red band light, the green band light, and the blue band light with respect to various color tones of the liquid S2 to be detected. Based on the light intensity signals of the red band light, the green band light, and the blue band light output from the light receiving body 32, the time average light intensity is calculated, or the specific color is absorbed. Using the intensity of the emitted light and the intensity of the light without absorption (which may store a representative value), the absorbance and transmittance of each of the red band light, the green band light, and the blue band light are calculated. A calculation unit that calculates, a selection unit that selects the color tone of the liquid S2 to be detected from the storage unit based on the absorbance and transmittance of the red band light, the green band light, and the blue band light; and the selected color tone And a display unit for displaying color numbers and color samples.

  In addition, when the color tone detection device 1A is specialized in detection of a specific color tone, the arithmetic processing device 6A does not calculate the absorbance and the transmittance for the red band light, the green band light, and the blue band light, respectively. A certain calculation (for example, red band light intensity / green band light intensity, red band light intensity / blue band light intensity, etc.) is performed on the transmitted light intensity of the liquid, and based on the calculated values, the liquid to be detected has a specific color tone. It may also be possible to detect whether or not

  In this color tone detection method, when detecting the color tone of the liquid S2 to be detected, a part of the light emitted from the light emitter 31 toward the liquid S2 to be detected is absorbed by the liquid S2 to be detected. After passing through the liquid to be detected S2, the light is reflected by the reflecting plate 21 on the opposite side of the light emitter 31, and again passes through the liquid to be detected S2 while being partially absorbed by the liquid to be detected S2. The light is received by the light receiving body 32 on the light emitting body 31 side. That is, in this color tone detection method, since the light from the illuminant 31 is transmitted so as to reciprocate in the liquid to be detected S2, the passage distance of the light passing through the liquid to be detected S2 is set to be twice or more than usual. The amount of light absorbed by the liquid S2 to be detected can be increased accordingly. For this reason, in this color tone detection method, the width size of the liquid S2 to be detected between the light emitter 31 or the light receiver 32 and the reflecting plate 21, that is, the width size T of the flow channel cross section of the measurement cell G can be reduced. As a result, the color tone detection device 1A can be reduced in size, and the cross section of the flow channel in the measurement cell G can be reduced, so that the amount of the sample to be detected liquid S2 and the necessary reagent can be reduced.

  Further, in this color tone detection method, the light receiving body 32 includes red band light obtained by substantially dividing the wavelength band of light in the visible light range out of the light from the light emitting body 3 that has passed through the liquid S1 to be measured. The green band light and the blue band light are received, and the intensity of each light is measured. For this reason, in this color tone detection method, even if any color tone is measured or the color tone of the liquid S1 to be detected changes with time, a simple set of the light emitter 31 and the light receiver 32 is provided. In many cases, it is not necessary to use a plurality of light emitters having different wavelengths depending on the number of colors to be detected, so that the detection cost can be reduced and the size of the detection apparatus can be reduced. For this reason, the mutual interference of the light which arises when using several light-emitting body simultaneously is not produced.

  Further, in this color tone detection method, the light emitter 31 only needs to emit light including a visible light range, and it is not necessary to emit only light of a specific wavelength. It is difficult to be affected by variations and changes in output with time, and this illuminant 31 can always be used for accurate measurement.

  Further, in this color tone detection method, even if dirt or bubbles adhere to the light emitting / receiving portions of the light emitter 31 or the light receiver 32 to cause a light attenuation effect, the light emitter (specification) used in the conventional measurement method is used. It emits light of a wavelength) and is less susceptible to the influence of a light receiving body and does not cause trouble in measurement.

  Further, in this color tone detection method, since the color of the reflecting surface of the reflecting plate 21 is white, the reflecting surface does not absorb only light of a specific wavelength, and the influence of light reflection can be suppressed to a small level.

  The above description regarding the color tone detection method applies similarly to the color tone detection apparatus 1A. In addition to the RGB color sensor, the photoreceptor 32 may use a CCD sensor or a CMOS sensor, and the same effect can be obtained by using a color filter having a band other than red, blue, and green. Can be obtained.

Next, a specific example of color tone detection by this color tone detection method will be described.
During the pulp and paper manufacturing process, there is a clarification process in which smelt-dissolved liquid (green liquid) is introduced into the clarifier and the dregs are separated from this clarifier, but the color of the supernatant liquid in the clarifier is greenish. It is known from experience that the refining process is well performed, and if it is tinged with red, the refining process is insufficient and affects the subsequent steps. Therefore, a clarifier supernatant liquid with insufficient clarification treatment is added with an agent (for example, a cationic polymer) that promotes clarification treatment (hereinafter referred to as a treated supernatant liquid) and a non-added clarifier liquid (hereinafter referred to as untreated supernatant). The change in the color of the supernatant liquid (change in transmittance) was verified by this color tone detection method using the color tone detection device 1A.

  Take 2 L of the supernatant with insufficient clarification treatment 1 L at a time, add 20 mg / L of the cationic polymer to one of the supernatants, stir, and immediately thereafter, treat the treated supernatant and the untreated supernatant with a tube pump. 40, the color tone (transmittance) was detected (measured) through the measurement cell G of the color tone detection apparatus 1A.

  In the untreated supernatant, the output value from the photoreceptor 32 (transmitted light intensity of each band light) increases and stabilizes with time, but in the treated supernatant, the output value from the photoreceptor 32 is Once it rises, it drops to the original value. This is thought to be because the untreated supernatant liquid causes precipitation and floc formation over time, and the amount of light transmitted increases, and in the treated supernatant liquid, precipitation and floc formation are caused by the addition of chemicals. This is thought to be due to the fact that this is suppressed.

  In the untreated supernatant, the values of (red band light transmittance / green band light transmittance) and (red band light transmittance / blue band light transmittance) increased with time. There was no change in these values in the finished supernatant. That is, the untreated supernatant liquid shows that the redness increases with the passage of time, and the treated supernatant liquid shows that the change from green to red is suppressed by the addition of the chemical.

  As described above, in this color tone detection method, the change in the property of the liquid S2 to be detected can be easily grasped using the output values (light intensity, transmittance, absorbance) of each band light, and the effect of adding the drug This can be similarly determined. Therefore, using this color tone detection method, chemical injection control and concentration management of chemicals can be easily performed.

  In addition, this color tone detection method makes it easy to detect leaks on the process side of colored liquids (for example, antifreeze liquids) and to manage wastewater treatment water at dyeing factories, food factories (such as tea), plating factories, and painting booths. It can be carried out.

DESCRIPTION OF SYMBOLS 1 Concentration measuring device 1A Color tone measuring device 31 Light emitter 32 Light receiver 21 Reflector F Filter H1 Liquid to be measured H2 Liquid to be detected

Claims (7)

Dissolve in the sample based on the transmittance or absorbance of light by transmitting light to the solution to be measured, which is colored by the addition of a reagent to the sample, or the sample to be measured that is colored by the lysate. A method for measuring a concentration of a lysate for measuring a concentration of a substance,
The light from the illuminant that has passed through the liquid to be measured is reflected by a reflector placed facing the light emitter so as to sandwich the liquid to be measured, and the reflected light is reflected on the liquid to be measured. A method for measuring the concentration of a lysate, wherein the lysate is again transmitted and then received by a light receiver on the light emitter side.   The light emitter emits light including a visible light region, and the light receiver is obtained by substantially dividing the light in the visible light region out of light from the light emitter transmitted through the liquid to be measured. Receiving light of a red region component, light of a green region component, and light of a blue region component, or receiving light of a plurality of color region components obtained by combining them. 1. The method for measuring a lysate concentration according to 1.   The method for measuring the concentration of dissolved matter according to claim 1, wherein the color of the reflecting surface of the reflecting plate is white. Dissolve in the sample based on the light transmittance or absorbance by transmitting light to the solution to be measured, which is colored by the addition of the reagent to the sample, or the sample to be measured that is colored by the lysate. An apparatus for measuring the concentration of a lysate that measures the concentration of an object,
A light emitter that transmits light into the liquid to be measured and a light emitter that is placed facing the light emitter so as to sandwich the liquid to be measured and reflects light from the light emitter that has passed through the liquid to be measured. A light receiving body that is disposed on the same side as the light emitter with respect to the liquid to be measured, is reflected by the light reflector, and receives light from the light emitter that has passed through the liquid to be measured again. An apparatus for measuring a concentration of a lysate. A color tone detection method for detecting the color tone of the liquid to be detected by receiving light from a light emitter that has passed through the liquid to be detected by a light receiver,
The light from the light emitter that has passed through the liquid to be detected is reflected by a reflecting plate placed opposite the light emitter so as to sandwich the liquid to be detected, and this reflected light is reflected by the light to be detected. After passing through the liquid again, it is received by the light receiver on the light emitter side,
In addition, the light emitter emits light including a visible light region, and the light receiver substantially divides light in the visible light region out of light from the light emitter transmitted through the liquid to be detected. A method for detecting a color tone, comprising: measuring the intensities of the obtained red region component light, green region component light, and blue region component light.   6. The color tone detection method according to claim 5, wherein the color of the reflection surface of the reflection plate is white. A color tone detection device that detects the color tone of the liquid to be detected by receiving light from a light emitter that has passed through the liquid to be detected by a light receiver,
A light emitter that transmits light in the liquid to be detected and a light emitter that is placed opposite the light emitter so as to sandwich the liquid to be detected, and reflects light from the light emitter that has passed through the liquid to be detected. A light receiving body that receives light from the light emitting body that is disposed on the same side as the light emitting body with respect to the liquid to be detected, is reflected by the light reflecting plate, and is transmitted again through the liquid to be detected; Have
In addition, the light emitter emits light including a visible light region, and the light receiver substantially divides light in the visible light region out of light from the light emitter transmitted through the liquid to be detected. A color tone detection apparatus comprising a filter for measuring the intensity of each of red region component light, green region component light, and blue region component light obtained.

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