JPH09258U - Turbidity sensor - Google Patents

Abstract

(57) [Summary] [Purpose] The objective is to obtain a turbidity sensor that can accurately detect turbidity even when left for a long period of time and is easy to maintain. A transparent cell 2 having a rectangular cross section is rotatably supported around a center point O of the cross section, and a transparent cell 2 having a distance S close to the center point O and not in contact with the cell 2 is provided. Sensors 4A, 4 for measuring the transparency inside the cell
B is confronted, and the transparent cell 2 is connected to the sensors 4A, 4
Intermittent rotation control is possible for each posture in which the surfaces 2A to 2D intersect at right angles to the measurement axis 4C of B, and the measured values measured during this intermittent rotation stop posture are alternately compared to detect the difference. It consists of the arithmetic circuit 5 and measures a constant turbidity regardless of the degree of contamination in the cell.

Description

[Detailed description of the invention]

[0001]

[Industrial applications]

 The present invention relates to improvement of a turbidity sensor used for water quality inspection.

[0002]

[Prior art]

 Conventionally, there is a turbidity sensor as a device for inspecting the water quality of material water such as tap water.As this turbidity sensor, the material water is circulated in a transparent tube, and the transparency is measured from outside the tube with, for example, an optical sensor. Things are known.

[0003]

[Problems of conventional technology]

 However, in the conventional turbidity sensor, water stains may adhere to the inside of the transparent tube during long-term use, and if such contamination occurs, accurate turbidity detection becomes impossible. Also, when cleaning these turbidity sensors, it is necessary to keep the cleaning tools clean, and maintenance and inspection are troublesome.

[0004]

[Problems to be solved by the device]

 In view of the above problems, the present invention has been made for the purpose of obtaining a turbidity sensor which can accurately detect turbidity even if left unattended for a long period of time and is easy to maintain and manage.

[0005]

[Means for Solving the Problems]

 That is, in the turbidity sensor of the present invention, the transparent cell 2 having a rectangular cross section is rotatably supported about the center point O of the above section, and the cell 2 does not come in contact with the center point O between them. Sensors 4A and 4B that measure the transparency in the cell 2 at a close distance of S are faced to each other, and the transparent cell 2 has each surface 2A to 2D perpendicular to the measurement axis 4C of the sensors 4A and 4B. The intermittent rotation control is possible for each of the intersecting postures, and the arithmetic circuit 5 is configured to alternately compare the measured values measured during the intermittent rotation stop posture and detect the difference.

[0006]

【Example】

 Next, an embodiment of the present invention will be described. FIG. 1 is a perspective view of an embodiment of the present invention, and FIG. 2 is a plan view of the embodiment.

In the turbidity sensor 1 of the present invention, a transparent cell 2 having a rectangular cross section is rotatably supported by a rotating device 3 about a center point O of the cross section, and the center point O is sandwiched between the cells. A sensor for measuring the transparency inside the cell 2 at a close distance within a range S that does not contact the cell 2, for example, a light emitter 4A and a light receiver 4B face each other. Intermittent rotation control is possible for each posture in which 2A to 2D intersect at a right angle, and it is composed of an arithmetic circuit 5 that alternately compares the measured values measured during this intermittent rotation stop posture and detects the difference. . In the above embodiment, the intermittent rotation control of the cell 2 is performed by directly controlling the drive motor M in addition to the gear mechanism that transmits the intermittent motion to the rotating device 3.

[0008]

[Action]

 When detecting the turbidity of the water quality with the turbidity sensor 1 of the present invention, the target material water is supplied into the cell 2 and the cell 2 is rotated intermittently about the center point O at 90 ° intervals. Then, at the time of intermittent stop, the turbidity between the surfaces 2A, 2C or 2B, 2D is measured by the sensors 4A, 4B.

At this time, the length of the short side is L _{1, the} length of the long side is L ₂ , the difference (L ₂ −L ₁ ) is L ₃ , and the light absorption amount of the sample water on the short side is a. ₁ , the light absorption amount due to dirt on the cell 2 is b, the light absorption amount of the sample water on the long side is a ₂ , and the difference (a ₂ -a ₁ ) is a ₃ , the difference between the measured values on both sides is Optical path length = L ₂ -L ₁ = (L ₁ + L ₃ ) -L ₁ = L ₃ (constant) Also, since the same cell 2 is used, the light absorption amount due to the case contamination can be considered to be the same value on each side. Therefore, the light absorption amount = (a ₂ + b)-(a ₁ + b) = (a ₁ + a ₃ + b)-(a ₁ + b) = a ₃ , and the light absorption amount a ₃ with a constant optical path length L ₃ is equal to the cell 2 It is possible to measure accurately regardless of the light absorption amount b due to dirt on the inner surface.

[0010]

[Effect of the invention]

 As described above, the present invention does not directly measure the transparency of water in a transparent channel when measuring the transparency, but indirectly determines the transparency by the difference in turbidity measured from two different directions. Since the measurement is performed, the value of the light absorption amount due to the stain on the inner surface of the cell 2 is canceled, and therefore, even if the cell 2 is soiled, the turbidity can be accurately measured. Further, from this, the cleaning management of the inner surface of the cell 2 is reduced and the maintenance management is facilitated.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of the present invention.

FIG. 2 is a plan view of the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Turbidity sensor 2 ... Transparent cell 2A-2D ... Each surface of cell 3 ... Rotating device 4A, 4B ... Sensor 4C ... Measurement axis of sensor 5 ... Arithmetic circuit O ... Center point of cell cross section S ... Contact with cell 2 Range not to be M ... Drive motor

Claims (1)

[Utility model registration claims] 1. A transparent cell 2 having a rectangular cross section,
Rotatably supported about the center point O of the cross section,
A sensor 4 for measuring the transparency in the cell 2 at a close distance within a range S that does not contact the cell 2 with the center point O interposed therebetween.
A and 4B face each other, and the transparent cell 2 is connected to the sensor 4
Intermittent rotation control is possible for each posture in which the surfaces 2A to 2D intersect at a right angle with respect to the measurement axis 4C of A and 4B, and the measured values measured during this intermittent rotation stop posture are alternately compared and the difference between them is determined. A turbidity sensor comprising an arithmetic circuit 5 for detecting.