JPH11241987A - Water quality measurement device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a water quality measuring device capable of measuring accurately over a wide concentration range. SOLUTION: Measurement cell parts 12a, 12b having different lengths.
Are provided in parallel, light sources 11a and 11b are provided at one end of each of the cell portions 12a and 12b, and detectors 14a and 14b are provided at the other end. Then, when the arithmetic unit 16 receiving the outputs of the two detectors 14a and 14b determines that the concentration of the sample liquid is very low, the cell unit 12a having a long cell length is selected and the concentration is determined to be extremely high. Selects the cell portion 12b having a short cell length. This enables accurate measurement over a wide concentration range.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for projecting a hue of a sample liquid by projecting light from one side and receiving the transmitted light on the other side and measuring at least the transmittance or concentration of the sample liquid. The present invention relates to a water quality measuring device for calculating and displaying color, degree of transparency, turbidity, and the like.

[0002]

2. Description of the Related Art At present, various methods are known for measuring the degree of coloring of factory wastewater and the like. Among them, wavelengths that give three kinds of stimuli are grouped into a series of X, Y, and Z (three stimulus values) for each type, and displayed by chromaticity coordinates xy (stimulus purity and dominant wavelength). The value of Z is calculated based on the sum of the transmittance in each wavelength region. Japanese Patent Application Laid-Open No. 7-43302 discloses that the intensity of coloring is proportional to the concentration of a coloring substance, and that the degree of coloring is determined by the magnitude of transmittance when light of a specific wavelength is transmitted through a sample solution. A measurement method representing the size is described.

FIG. 3 schematically shows a basic device for measuring the degree of coloring of a sample liquid using the above-described measuring method, and is mainly a light source which emits white light or light of a specific wavelength. 1, a measurement cell (flow cell) 2 to which an inflow pipe 8 and an outflow pipe 9 are connected and through which a sample solution flows continuously, a detector 4 for receiving light transmitted through the measurement cell 2 via a condenser lens 3, and this detector 4 And an arithmetic unit 6 for receiving at least the output from the amplifier 5 through the amplifier 5 and calculating at least the transmittance or concentration of the sample liquid, and displaying the transmittance or concentration of the sample liquid calculated by the arithmetic unit 6 on an external device such as a computer. An output device 7 is provided. Based on the transmitted light, the sample liquid is calculated for transmittance or concentration (also called optical density or absorbance as a common logarithm of the reciprocal of the transmittance), and the coloring degree, hue, transparency, Turbidity and the like are measured.

[0004]

The concentration of factory effluent changes every moment. When measuring a liquid having a very low concentration, the difference from the reference color (distilled water) is not clearly observed. It is necessary to measure the transmittance or the concentration by increasing the length of the cell 2. However, when a long measuring cell is used, light having a very high concentration does not transmit light, so that the amount of light detected by the detector 4 becomes small, and as a result, it becomes difficult to perform accurate measurement. As described above, it is impossible with the conventional configuration to accurately measure the transmittance or concentration of factory wastewater whose water quality changes continuously, and accurate measurement can be performed only in a narrow concentration range.

[0005] The present invention has been made in view of the above problems, and it is an object of the present invention to provide a water quality measuring device capable of measuring accurately over a wide concentration range.

[0006]

The above objects are attained by a light source,
A measurement cell made of a transparent material containing a sample liquid, a detector for detecting light emitted from the light source and passing through the measurement cell, and at least the transmittance or concentration of the sample liquid based on the output of the detector. In the water quality measurement device provided with an arithmetic device for calculating, the measurement cell is composed of a plurality of cell portions having different lengths in parallel with each other, and the light source is provided at one end of each of the cell portions, and the other end is provided with the light source. The water quality measuring device is provided with a detector.

[0007] Further, the above problems are a light source, a measuring cell made of a transparent material containing a sample solution, a detector for detecting light emitted from the light source and passing through the sample solution, and an output of the detector. A water quality measuring device comprising at least one of a light source and the detector at one end of the measuring cell, and a measuring device for measuring the other one of the light sources. A water quality measuring device is provided inside a cell, and the other is movable along an axial direction of the measuring cell.

According to the present invention, the measurement is performed while changing the length of the measuring cell in accordance with the concentration of the sample liquid. The cell portion is used in accordance with the concentration of the sample solution. According to the fourth aspect of the present invention, one of the light source and the detector is fixed and the other is movable, so that the measurement can be accurately performed even on a sample liquid whose concentration continuously changes.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a first embodiment of the present invention. Between the inflow pipe 18 and the outflow pipe 19, two measurement cell portions 12a and 12b having different lengths are provided in parallel with each other. These measurement cell sections 12a and 12b are configured as flow cells through which a sample solution flows continuously, and light sources 11a and 11b are provided on one end side, respectively, and the measurement cell sections 12a and 12b are provided on the other end side.
Detectors 14a and 14b are provided for receiving the transmitted lights of a and 12b via the condenser lenses 13a and 13b. The outputs of these detectors 14a and 14b are respectively connected to an amplifier 15a.
And 15b are supplied to the arithmetic unit 16 and the arithmetic unit 16 calculates the transmittance, the concentration (absorbance), the tristimulus value and the like, and determines the predetermined water quality of the sample liquid, for example, the degree of coloring, hue, transparency, turbidity Measure etc. This output signal is output to output device 17.
And displayed on an external device such as a computer.

Therefore, in this embodiment, the sample liquid is allowed to flow through the two measurement cell sections 12a and 12b, and the outputs of the detectors 14a and 14b are supplied to the arithmetic unit 16 at the same time. At this time, each measurement cell unit 12a, 12b
The measurement concentration range is determined in advance, and when the concentration of the sample solution reaches the boundary concentration (threshold), one of the outputs of the detectors 14a and 14b is selected (the measurement cell unit to be used). Is selected).

That is, assuming that a sample solution having a certain concentration range is flowing, it flows into each measurement cell unit 12.
If the measured concentration ranges a and 12b are within the respective ranges (if the outputs of the detectors 14a and 14b are equal), the arithmetic unit 16 selects one of them and measures the above-mentioned predetermined water quality. If the concentration of the sample liquid becomes extremely low with the passage of time, the output of the two detectors 14a and 14b will differ. This is due to the deviation of the measured concentration range in the detector 14b on the side of the measuring cell unit 12b having a short cell length. At this time, the arithmetic unit 16 selects an output value of the detector 14a on the side of the measurement cell unit 12a having a long cell length, and calculates various data based on the output value. on the other hand,
When the concentration of the sample liquid is very high, the output value of the detector 14b on the measurement cell section 12b side having a short cell length is selected, and various data are calculated based on the output value.

Therefore, according to the present embodiment, it is possible to measure a sample solution over a wide concentration range, and it is possible to always measure a sample solution having a continuously changing concentration with high accuracy.

FIG. 2 shows a second embodiment of the present invention. In the figure, the same reference numerals are given to portions corresponding to the first embodiment.

The measuring cell 22 is configured as a flow cell, and a light source 21 is provided at one end thereof. On the other hand, a driven member 30 is inserted into the other end of the measurement cell 22 in a liquid-tight manner, and a condenser lens 23 and a detector 24 for detecting transmitted light of the sample liquid are accommodated therein. One end of the driven member 30 facing the light source 21 is formed of a transparent material 30a, and the other end is provided with a linear motor 3 as a driving unit.
1 has a metal shaft portion 30b that can be driven in the axial direction. That is, the driven member 30 can be moved in the direction of the arrow inside the measurement cell 22 by driving the linear motor 31. The linear motor 31 is driven by a drive unit 32 in accordance with a drive signal S issued from the arithmetic unit 16 that receives the output of the detector 24 via the amplifier 25.

The driving signal S indicates the stop position of the driven member 30 with respect to the measuring cell 22, that is, the light source 21 and the detector 2
4 is a control signal that determines the distance from the control signal 4 and is transmitted according to the detection output of the detector 24. That is, the distance between the light source 21 and the detector 24 (in other words, the cell length) according to the concentration of the sample solution.
Is transmitted to the driving device 32 in order to move the detector to an optimum position corresponding to the preset concentration.

Therefore, according to the present embodiment, the same effects as those of the first embodiment can be obtained.
The water quality of the sample liquid can be accurately measured over a wide concentration range, and the light source and the detector can be used as one set as compared with the configuration of the first embodiment.

Although the embodiments of the present invention have been described above, the present invention is, of course, not limited to these embodiments.
Various modifications are possible based on the technical idea of the present invention.

For example, in the above first embodiment, 2
Although two measurement cell sections 12a and 12b are provided and two sets of measurement systems are provided, three sets, four sets or more sets may be provided as necessary. Thereby, the measurement in any concentration range can be performed with high accuracy, and the accuracy can be improved.

In the above-described second embodiment, the light source 21 is fixed and the detector 24 is movable. However, this is reversed, and the detector 24 is fixed to one end of the measuring cell 22, and the light source 21 is fixed. 21 may be movable inside the measurement cell 22.

Although the linear motor 31 is applied as the driving unit, the driven member 30 may be driven by an air cylinder or a gear mechanism instead. Or,
It is also possible simply by manual operation by the measurer.

Further, in each of the embodiments described above, the flow cell is used as the measurement cell, but the same effect can be obtained by using this as a fixed cell.

[0023]

As described above, according to the water quality measuring apparatus of the present invention, it is possible to measure a sample solution over a wide concentration range, and to always obtain a high accuracy for a sample solution having a continuously changing concentration. Can be measured.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically showing a first embodiment of the present invention.

FIG. 2 is a cross-sectional view schematically showing a second embodiment of the present invention.

FIG. 3 is a sectional view showing a conventional water quality measuring device.

[Explanation of symbols]

 Reference Signs List 11a light source 11b light source 12a measurement cell 12b measurement cell 14a detector 14b detector 16 arithmetic unit 21 light source 22 measurement cell 24 detector 30 driven member 31 linear motor

Claims (8)

[Claims] 1. A light source, a measurement cell made of a transparent material containing a sample liquid, a detector for detecting light emitted from the light source and passing through the measurement cell, and at least the detector based on an output of the detector. A water quality measurement device comprising a calculation device for calculating the transmittance or concentration of the sample liquid, wherein the measurement cell is composed of a plurality of cell portions having different lengths in parallel with each other and the one end side of each of the cell portions. A water quality measuring device, wherein a light source is provided on each of the other ends of the detectors. 2. The water quality measuring device according to claim 1, wherein the arithmetic device selects one of the outputs of the detectors based on a transmittance or a concentration of the sample liquid. 3. The water quality measuring device according to claim 1, wherein each of the cell sections is a flow cell through which a sample liquid flows continuously. 4. A light source, a measuring cell made of a transparent material containing a sample liquid, a detector for detecting light emitted from the light source and passing through the sample liquid, and at least the light source based on an output of the detector. In a water quality measurement device including a calculation device for calculating the transmittance or concentration of a sample liquid, one of the light source and the detector is provided at one end of the measurement cell, and the other is provided inside the measurement cell. , Wherein the other is movable along the axial direction of the measurement cell. 5. The water quality measurement device according to claim 4, wherein the light source or the detector is moved in accordance with a drive signal transmitted from the arithmetic device based on a transmittance or a concentration of the sample liquid. 6. The light source or the detector is accommodated in a driven member that is movable in the axial direction and is transparent in at least the axial direction in the measurement cell, and the driven member transmits the drive signal. The water quality measuring device according to claim 5, wherein the water quality measuring device is driven by a driving unit that operates upon receiving the water. 7. The water quality measuring device according to claim 6, wherein the driving section is a linear motor. 8. The water quality measuring device according to claim 4, wherein the measuring cell is a flow cell through which a sample liquid flows continuously.