JP4919003B2 - Turbidity measuring instrument - Google Patents

Description

The present invention relates to a turbidity meter, but details about the turbidity measuring instrument by improving the calibration plate of meter calibration turbidity meter.

As shown in FIG. 7, the conventional turbidity measuring device applies light emitted from the light source 111 to the side surface of the sample channel 114 in which the measurement water 113 flows as parallel light by the lens 112. The transmitted light that has passed through the measurement water 113 in the sample channel 114 is detected by the transmitted light receiving unit 115 (this value is I _T ), and scattered light scattered by the particles (floating matter) in the sample channel 114 is scattered. Detection is performed by the light receiving units 116a and 116b (this value is I _S ). Light receiving portions 115,116A, obtains the turbidity by the ratio calculation of the resulting scattered light intensity _{I S} and the transmissive light quantity _{I T} at 116 b. At this time, it is required that I _S / _IT has a linear relationship with the concentration of particles (floating matter).

The intensity of transmitted light and scattered light is set as I _T and I _S , respectively, and the ratio: I _S / I _T is obtained.
_{I S / I T = I S} (0) / I T (0) + αLN
N; turbidity alpha; optical path length I T ₍₀₎ of the measuring tank; turbid component, constants L determined by the shape and characteristics of the detection unit transmitted light intensity I S ₍₀₎ in the case of turbidity 0 degrees; Pollution The intensity of forward scattered light in the case of 0 degree is the scattered light / transmitted light ratio (I _S / I _T ), which is proportional to turbidity (N).

There is also a turbid chromaticity meter seeking absorbance from the transmitted light intensity I _T seek turbidity and chromaticity.

  A calibration plate 117a (117b, 117c) made of acrylic resin is inserted into the sample channel 114 or the left and right spaces of such a measuring instrument, and the instrument is periodically calibrated.

  As shown in FIG. 8, the calibration plate 117a (117b, 117c) has a configuration in which a diffusing agent 118 or the like is mixed or colored with an acrylic resin as a calibration plate material in order to scatter and absorb the applied light. ing.

Such calibration using the calibration plate 117a (117b, 117c) has the advantage that it does not take time to produce a standard solution and can be used repeatedly as compared with calibration using a standard solution.
Japanese Unexamined Patent Publication No. 2000-273666 (page 2 to page 3 FIG. 1)

However, in a turbidity measuring instrument that calibrates using the calibration plate described in the prior art, a diffusing agent or the like is mixed with the acrylic resin of the calibration plate material to scatter and absorb the light applied to the calibration plate. I'm coloring. Since the amount of the coloring component such as the diffusing agent cannot be accurately controlled, the color of the material and the amount of the diffusing agent vary depending on the production lot. Therefore, it is necessary to change the thickness of the calibration plate depending on the lot.
There is also a problem in that it is difficult to select the material because the material must be selected from the manufacturer in order to produce the light quantity necessary for calibration.

Further, when both turbidity and chromaticity are measured with a single measuring instrument, a glass plate having a structure for measuring turbidity and turbidity by absorbance can be used as a calibration plate. However, in a measuring instrument that measures chromaticity by absorbance and calculates turbidity from only scattered light or the ratio of transmitted light to scattered light, two calibration plates are required. When simulating scattered light with a calibration plate, it is necessary to mix a diffusing agent with acrylic resin. When this calibration plate is used, it can be used as a calibration plate for turbidity. However, when it is used as a calibration plate for chromaticity due to excessive light absorption, the measurement range may be exceeded.
For this reason, since two calibration plates are used, it takes time for calibration and costs for two sheets are required.

  Therefore, there is a problem to be solved by providing an accurate point or space imitating the particles to be measured inside a calibration plate used in a measuring instrument for measuring turbidity and turbidity.

In order to solve the above problems, the turbidity measuring instrument of the present invention is configured as follows.

(1) A turbidity measuring device includes a light emitting unit for irradiating light to a sample flow path through which a measurement target flows, a light receiving unit for receiving transmitted light and / or scattered light transmitted through the sample flow path, and the sample flow A turbidity measuring instrument comprising a calibration means for calibrating the instrument by inserting a calibration plate at a position where light passing through the path is blocked, and the calibration plate used in the calibration means is a transparent glass member A point or space simulating the particles contained in the measurement object is arranged inside the transparent glass member , and the point or space arranged inside the calibration plate constitutes the calibration plate with a laser beam. This is a trace of the glass being melted inside the transparent glass .

According to this proposal, depending on the components and coloring lots that diffuse light like a calibration plate of the prior art by freely placing a point or space where glass or transparent resin is melted inside transparent glass or transparent resin There is an effect that it is possible to provide a calibration plate that can stably obtain the amount of scattered light and the amount of absorbed light regardless of variations.
In addition, since processing is performed inside the calibration plate, bubbles are prevented from adhering to the calibration plate surface, and the measurement can be performed more accurately.

Next, an embodiment of a turbidity measuring device according to the present invention will be described with reference to the drawings.

The turbidity measuring device of the present invention will be described.
As shown in FIGS. 1 and 2, the turbidity measuring device includes a light source 11, a lens 12 that converts a light beam from the light source 11 into a parallel light beam, and a measurement liquid 14 to be measured inside a transparent glass plate 13. Included in the sample flow path 16, the transmitted light receiving portions 18 a and 18 b that receive the transmitted light 17 that has passed through the measurement liquid 14 in the sample flow path 16, and the measurement liquid 14 in the sample flow path 16. Calibration of the instrument by inserting the scattered light receivers 21a and 21b that receive the scattered light 19a and 19b scattered by the particles 15 and a calibration plate 22 (see FIG. 2) at a position that blocks the light that passes through the sample channel 16 And a calibration means for performing the above.

In the turbidity measuring instrument having such a configuration, the light emitted from the light source 11 is collimated by the lens 12 and applied from the side surface of the sample channel 16 through which the measurement liquid 14 flows. The transmitted light 17 that has passed through the measurement liquid 14 in the sample channel 16 is detected by the transmitted light receivers 18a and 18b with optical filters (this value is I _T ), and particles (floating matter) in the sample channel 16 are detected. The scattered light 19a and 19b scattered by the light 15 is detected by the scattered light receivers 21a and 21b with an optical filter for measuring turbidity (this value is I _S ).

Light receiving portions 18a, 18b, 21a, the turbidity by the ratio calculation of the resulting scattered light intensity _{I S} and the transmissive light quantity _{I T} at 21b obtains. At this time, it is required that I _S / _IT has a linear relationship with the concentration of the particles (floating matter) 15. Since this point has been described in the prior art, its description is omitted.

  As shown in FIG. 2, the calibration means periodically calibrates the instrument by inserting a calibration plate 22 into a position where light passing through the sample channel 16 of the measuring instrument is blocked, in the embodiment, the sample channel 16. .

The calibration plate 22 is made of transparent glass or resin, and has a configuration in which a point or space simulating the particles to be measured is created and arranged two-dimensionally or three-dimensionally.
A technique for creating a point or space inside the calibration plate 22 is to apply a laser beam to the inside of the glass (crystal glass) to melt the glass and leave a trace of melting. Using this technology, a calibration plate is created in which a point or space simulating the particles to be measured is created inside the glass and is arranged two-dimensionally or three-dimensionally.

The calibration plate 22 shown in FIG. 3 is a glass (crystal glass) or transparent resin that uses a laser beam to freely dispose a glass (crystal glass) or transparent resin melting point or a space 23. .
This makes it possible to obtain a calibration plate that can stably obtain the amount of scattered light and the amount of light absorption without being affected by variations due to light diffusing components and coloring lots, as in the case of a calibration plate of the prior art.
In addition, since the calibration plate is processed, it is possible to prevent bubbles from adhering to the calibration plate surface when inserted into the sample channel. By preventing the bubble from adhering to the light, it is possible to prevent the disturbance of the light beam caused by the bubble and perform accurate measurement.

  The calibration plate 22 shown in FIG. 4 is a point or space 24 in which particles are simulated on the calibration plate when a plurality of photodetectors are provided with functions such as chromaticity measurement and turbidity measurement using a laser beam. Is a calibration plate that can calibrate calculation signals from a plurality of photodetectors with a single calibration plate.

  The calibration plate 22 shown in FIG. 5 is a calibration plate in which a point or space 25 simulating particles to be measured using a laser beam is three-dimensionally arranged.

  The calibration plate 22 shown in FIG. 6 processes a hemispherical depression (recess) 26 simulating particles contained in a measurement object on the surface of glass or a transparent resin material which is a transparent member, and the processed surface is processed. It is a calibration plate created by pasting together. This is a point or space that simulates the particles to be measured in the calibration plate that is bonded together.

As described above, it is difficult to suppress light absorption with a calibration plate that is mixed or colored with a diffusing agent as in the prior art, and a turbidity measurement calibration plate that produces scattered light and appropriate light absorption. A chromaticity calibration plate is required to obtain In contrast, if the calibration plate is processed as in the present invention, the absorption of light can be suppressed and scattered light can be generated.
Therefore, it is possible to use as a calibration plate for both chromaticity measurement and turbidity measurement with a single calibration plate in which points or spaces that are equally simulated to the particles to be measured are arranged.

In the above description, a turbidity measuring instrument using a calibration plate is exemplified as a measuring instrument using transmitted light and scattered light, but the turbidity measuring instrument is not limited to this type. For example, only scattered light may be used.

By freely arranging the melting point or space of glass or transparent resin inside transparent glass or transparent resin, it is not affected by variations due to light diffusing components or coloring lots like the conventional calibration plate Provided is a turbidity measuring instrument using a calibration plate that can stably obtain the amount of scattered light and the amount of light absorbed.

It is the block diagram which showed schematically the turbidity measuring device of this invention. A state in which turbidity insert a calibration plate to the measuring instrument of the present invention is a configuration diagram illustrating a substantially expressly. It is explanatory drawing which showed schematically the calibration board of this invention used with a turbidity measuring device similarly. It is explanatory drawing which showed schematically the calibration board of this invention used with a turbidity measuring device similarly. It is explanatory drawing which showed schematically the calibration board of this invention used with a turbidity measuring device similarly. It is explanatory drawing which showed schematically the calibration board of this invention used with a turbidity measuring device similarly. It is the block diagram which showed schematically the turbidity measuring device in a prior art. It is explanatory drawing which showed schematically the calibration board used for the turbidity measuring device in a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Light source 12 Lens 13 Transparent glass plate 14 Measurement liquid 15 Particle 16 Sample flow path 17 Transmitted light 18a Transmitted light receiver 18b Transmitted light receiver 19a Scattered light 19b Scattered light 21a Scattered light receiver 21b Scattered light receiver 22 Calibration plate 23 Point or space 24 point or space 25 point or space 26 depression

Claims (1)

A light emitting unit for irradiating light to the sample flow path through which the measurement object flows;
A light receiving portion for receiving transmitted light and / or scattered light transmitted through the sample flow path;
Calibration means for calibrating the instrument by inserting a calibration plate at a position that blocks light transmitted through the sample flow path,
A turbidity measuring device comprising:
The calibration plate used in the calibration means is formed of a transparent glass member , and places a point or space simulating particles contained in the measurement object inside the transparent glass member ,
The turbidity measuring instrument according to claim 1, wherein the point or space disposed inside the calibration plate is a trace of glass melted by applying a laser beam to the inside of the transparent glass member .

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