JPH02268251A - Turbidity measuring apparatus - Google Patents

Abstract

PURPOSE:To make the measured value accurate when relatively pure water is measured by providing a network body having small mesh at the sample sucking port of a measuring cell, and preventing the sucking of bubbles and relatively large grains in a sample to be measured when the sample to be measured is sucked. CONSTITUTION:A measuring cell 7, a wiper 9, a light source lamp 10 and a light receiving cell 11 are contained in a casing 12 of a detecting head 1. A network body 22 is provided at a sample sucking port 8 which is opened at the lower part of the measuring cell 7. Solid matters having the large grain sizes such as sand and dust in a sample to be measured which is sucked through a sample sucking port 8 are filtered through the network body 22. Thus the turbidity which is larger than the actual turbidity of the relatively pure sample is not measured because the following phenomenon can be prevented: sand, other solid matters, bubbles and the like which are not mixed uniformly in the sample itself are sucked into the measuring cell 7.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) This invention relates to a turbidity measuring device for measuring the turbidity of water in water purification plants, sewage treatment plants, industrial wastewater facilities, and the like.

(Prior Art) Generally, devices shown in FIGS. 2 to 4 are known as water turbidity measuring devices used in water purification plants, sewage treatment plants, industrial wastewater facilities, and the like.

This in-shell turbidity measuring device consists of a detection head 1, which is submerged in water, sucks a measurement sample into an internal measurement cell, and optically detects turbidity, and a fixed part. 2
The holder 4 is supported by a mounting bracket 3 against the holder 4, amplifies the turbidity signal optically detected within the detection head 1, and supplies power to various electrical components provided within the detection head 1. Detector 5 with built-in power supply etc.
and a signal processing section 6 that processes the signal from the detector 5 to determine turbidity and displays it. .

As shown in detail in FIG. 4, the internal structure of the detection head 1 includes a measuring self made of transparent glass, and a measuring self that moves up and down in close contact with the inside of the measuring self to detect a sample to be measured. Inhale water through sample inlet 8.
A wiper 9 that discharges the liquid, a light source lamp 10 that emits light to the measurement sample taken in during the measurement self, and this light source lamp 1.
A light-receiving cell 11 that receives light emitted from zero and passing through a measurement sample in a measurement cell is provided, and these cells are housed in a casing 12.

In addition, 13 in FIG. 4 is a wiper shaft,
This wiper shaft 13 is moved up and down by the rotational force of a motor (not shown), and the wiper 9 is moved up and down within the measuring self.

Further, 14 is a shaft guide, which is sealed to prevent the measurement sample from entering the inside of the shaft 13 from the measurement self.

Furthermore, the electrical circuit configuration of this turbidity measuring device is shown in FIG. A light receiving cell llb for the light scattered by the measurement sample in the measurement cell 11a is provided, and a signal amplifier 17a for the transmitted light light receiving cell 11a.

a signal amplifier 17b for the scattered light receiving cell llb;
Further, an arithmetic circuit 18 which calculates the turbidity by calculating the detection signals from these amplifiers 17a and 17b, and this arithmetic circuit 18
Based on the calculation result, the turbidity display 19 displays the turbidity digitally, and transmits the turbidity data to the computer of the central turbidity monitoring facility connected to it, and further includes a range selector switch 20. A signal conversion circuit 21 is provided.

In such a conventional turbidity measuring device, a wiper drive circuit 15 rotates a motor (not shown) to drive the wiper shaft 9 up and down.

Then, when the wiper 9 moves up, the measurement sample is sucked into the measurement cell through the sample suction port 8. At this time,
When the lamp power source 16 turns on the light source lamp 1°, the light that enters the measuring cell from the light source lamp 1o and passes through the measurement sample is directly received by the transmitted light receiving cell lla, and at the same time, the scattered light scattered by the measurement sample is Scattered light receiving cell ll
The light is received by b.

The light-receiving cells lla and llb output signals proportional to the amount of light received, which are amplified by amplifiers 17a and 17b and supplied to the arithmetic circuit 18.

The arithmetic circuit 18 calculates the amount of scattered light/the amount of transmitted light from the signals from the amplifiers 17a and 17b to obtain turbidity, and inputs the signal to the conversion circuit 21.

The conversion circuit 21 displays the turbidity digitally on the display 19 from the turbidity signal obtained by the arithmetic circuit 18, and also transmits the signal.

The wiper 9 slides in close contact with the inner surface of the measuring self by its vertical movement, and at this time wipes away dirt adhering to the inner surface of the measuring self, thereby preventing a decrease in the transparency of the measuring self.

(Problem to be Solved by the Invention) However, in such a conventional turbidity measuring device, it is not possible to intermittently determine the turbidity by sucking the n1 constant sample into the measurement cell by raising the wiper. However, since the sample inlet 8 of the measurement self-measuring device is simply made with a hole, solid matter such as sand may settle at the bottom of the water reservoir, but the water itself as the measurement sample When measuring the turbidity of water that is relatively clear, remove sand and other sediments that settle at the bottom when the wiper 9 sucks the water together with the clear water. If inhaled, the precipitate acts as a pollutant and obstructs the transmission of light from the light source lamp 1o, increasing scattered light, resulting in a turbidity n1 constant value that is higher than the actual turbidity of water. There was a problem.

The present invention has been made in view of such conventional problems, and provides a turbidity measuring device that can accurately measure turbidity in relatively clear water such as tap water. The purpose is to

[Structure of the Invention] (Means for Solving the Problems) The turbidity measuring device of the present invention is provided with a fine mesh at the sample inlet of the measurement cell, so that when the measurement sample is inhaled, air bubbles and This is designed to prevent inhalation of relatively large particles.

(Function) In the turbidity measuring device of the present invention, by attaching a fine mesh member to the sample inlet of the measurement cell, when the wiper sucks the measurement sample into the measurement cell through the sample inlet, the measurement If the sample contains particles with a particle size larger than the mesh size, it is possible to prevent the inhalation of such large particles. When measuring turbidity, it is possible to prevent unnecessary particles from being sucked into the measurement cell and impairing the reliability of the turbidity measurement value.

(Example) Hereinafter, embodiments of the present invention will be explained in detail based on the drawings.

The turbidity measuring device of the present invention is characterized by the detection head, and other parts have almost the same configuration as the general mechanical configuration and electric circuit configuration shown in FIGS. 2 to 4. It is.

Therefore, the configuration of the detection head 1 will be explained below with reference to FIG.

FIG. 1 shows a detection head 1 according to an embodiment of the present invention, in which a measuring self-container is installed in a casing 12, similar to the conventional example.
A wiper 9, a light source lamp 10, and a light receiving cell 11 are housed therein, and a net-like body 22 is provided at a sample inlet 8 that is open at the bottom of the measuring cell. Note that 13 is a wiper shaft and 14 is a shaft guide.

The mesh size of this net-like body 22 is not particularly limited, but it depends on the clarity of the water storage tank used + the water as a constant sample, and the particle size of solids such as sand precipitated there. Determined by

Next, the operation of the turbidity measuring device having the above configuration will be explained.

When measuring the turbidity of water as a measurement sample, a wiper drive circuit 15 drives a motor (not shown),
The wiper 9 is raised and the n1 constant sample is sucked into the measurement self from the sample suction port 8.

At the same time, the light source lamp 10 is turned on by the lamp power source 16, and the light transmitted through the measurement sample in the measurement cell and the light scattered are sent to the transmitted light receiving cell lla.
and the scattered light receiving cell llb, and the arithmetic circuit 18 measures the turbidity from the ratio of the amounts of received light, displays it on one turbidity display, and outputs the turbidity measurement data to the outside as necessary. do.

Here, when the measurement sample is inhaled from the sample suction port 8, the sample passes through the mesh body 22 and is inhaled into the measurement cell, and large particles such as sand and dirt are contained in the sample. Even if solid matter is mixed in, the unnecessary solid matter can be filtered out through the mesh, and it is relatively clear and is not uniformly mixed in the sample itself, causing water pollution. This prevents sand, other solid matter, or air bubbles from being sucked into the measurement cell and causing a turbidity n1 to be determined to be higher than the actual turbidity.

[Effects of the Invention] As described above, according to the present invention, a mesh body is attached to the sample inlet of the measurement cell to prevent large solids from being sucked into the measurement cell together with the measurement sample. Although it is relatively clear, especially like tap water, it settles at the bottom of a water tank.

Sand or other solid materials that do not have a negative effect on water pollution may be sucked into the measurement cell at the same time as the measurement sample is inhaled, resulting in a turbidity measurement that is higher than the actual turbidity. This allows for accurate turbidity measurements.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a detection head according to an embodiment of the present invention, FIG. 2 is an overall view of a general turbidity measuring device, FIG. 3 is a circuit diagram of a general turbidity measuring device, and FIG. The figure is a sectional view of a conventional detection head. 1...Detection head 7...Measurement cell 8...
Sample inlet 9...Wiper 10...Light source lamp 11...Light receiving cell 12...Casing

Claims (1)

[Scope of Claims] A turbidity measuring device that optically measures turbidity by intermittently sucking a measurement sample into a measurement cell from a sample inlet, comprising: a fine mesh member provided at the sample inlet of the measurement cell; established,
A turbidity measuring device configured to prevent air bubbles and relatively large particles in a measurement sample from being inhaled when the measurement sample is inhaled.