JPS63214646A - Turbidimeter - Google Patents

Abstract

PURPOSE:To exactly measure the turbidity of a specimen liquid by measuring the periodicity of light obtd.. by stirring a liquid suspension and casting light thereto by an optical method. CONSTITUTION:The specimen liquid 7 is put into a turbidity measuring vessel 6 where the liquid 7 is uniformly stirred by a stirring element 5. The element 5 is rotated by a stirrer 4. The light from a light source is projected to the uniformly stirred liquid 7 by a light projecting means 2. The light past the vessel 2 is entered through a photodetecting means 3 to an optical power meter 8. The electric signal subjected to photoelectric conversion in the optical power meter 8 is sent via a coaxial cable 9 to a recorder 10. The turbidity of the liquid to be measured is thus exactly measured by detecting the periodicity of the light.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention efficiently controls the turbidity of suspension solutions that can be used in manufacturing process management or research and development in the paper industry, ceramic industry, pharmaceutical industry, food industry, etc. This relates to a turbidity meter that can measure turbidity.

[Conventional technology]

The following five methods are conventionally known as methods for measuring the turbidity of suspended solutions and the like.

+11 Transmitted light titration method: Light is applied from one side of the turbidity measurement liquid tank, and all of the transmitted light is measured on the opposite side, and the degree of increase or decrease in the value is proportional to the concentration of suspended solids in the measurement liquid. This method is used to determine the concentration of turbid substances, and although it is a furnace method based on basic principles, it is easily affected by the degree of coloration of the suspension and has the disadvantage that it cannot be used as a continuous measurement method.

(2) Surface scattered light measurement method: A source is applied to the surface of the suspension measurement liquid,
It measures the scattered light from the liquid surface, and has the advantage of being less affected by scattering and even if the liquid to be measured is colored. There is a drawback that bubble particles present in the measurement liquid cause measurement errors.

(3) Scattered light, transmitted light measurement method: In this method, light is incident on the liquid to be measured, and both the transmitted light and the scattered light of the incident light are measured, and the ratio of these two is determined by the amount of light in the liquid to be measured. This method calculates the concentration of suspended solids in a liquid to be measured using the fact that it is proportional to the concentration of suspended solids. In principle, this method has the advantage that measurement errors such as fluctuations in the power supply, deterioration of the rung, coloring of the liquid to be measured, and dirt on the measurement window of the measuring device are unlikely to occur as measurement errors, but the measurement system is complicated. There are some difficulties.

(4) Scattered light measurement method: In this method, the principal is introduced into the measurement system and only the scattered light generated inside the measurement liquid is measured, and its intensity is proportional to the concentration of suspended solids in the measurement liquid. This method uses the method to determine the concentration, but it has the drawback that dirt on the window of the device to be measured can affect the measurement results.

(5) Integrating sphere method: In this method, a liquid to be measured is placed in an integrating sphere using the method specified in JIS K O101, light is incident on the integrating sphere, and the resulting scattered light and total incident light are measured respectively. However, the turbidity is measured by utilizing the fact that the ratio of the two is proportional to the concentration of suspended matter in the liquid to be measured. In this method, the measurement of scattered light and total incident light must be carried out while replacing the light wrap and white plate at each light outlet, which has the disadvantage that continuous measurement of the liquid to be measured is not possible.

[Problem to be solved by the invention] The phenomenon that water appears to be caused by the presence of particles in an aqueous solution that are very large compared to the size of water molecules and normal ions that can be dissolved in water, such as clay particles, plankton, etc. This means that large molecules or polymers such as starch or proteins are present. Since the nitrite present in this liquid is unstable and the properties of the liquid naturally change over time after sampling, it is desirable to measure the turbidity of the liquid immediately after sampling. If the water has to be left for a long time after being sampled before being measured, the only way to measure turbidity is to dig vigorously into the water sampling bottle and measure the suspended solids in a completely suspended state. It is questionable how accurately the measured values obtained in this way measure the degree of suspension in natural conditions, so it is necessary to clearly state the measurement conditions when recording the measured values. Become. The turbidity measurement method currently being developed selects and measures one of the properties of scattering, reflection, and absorption of light by particles existing in a suspension, and expresses the amount of light, thereby determining the amount of light in the liquid to be measured. Measuring the degree of bitterness. Therefore, the measured value is a shadow of the dirt on the measuring instrument window! #
The problem is that you can't avoid being attacked.

[Means for solving problems]

Therefore, the present inventors are currently considering developing a turbidity meter that can accurately and quickly measure the turbidity of a sample liquid without the above-mentioned difficulties. He discovered that there was a certain periodicity when exposed to light.
By measuring this periodicity using an optical method and converting this measured value into a value, it is possible to accurately measure the turbidity of the liquid to be measured, and also to quickly measure it. They discovered this and completed the present invention.

The gist of the present invention is a container for measuring turbidity of a suspension;
It is equipped with means for stirring the suspension in the container, means for projecting light onto the turbidity measuring device, means for receiving light that passes through the turbidity measuring container, and means for analyzing and outputting the optical period of the amount of received light. It's on the turbidity meter.

FIG. 1 shows a schematic diagram of the turbidity meter of the present invention.

In the figure, fi+ is the light source, (21 is the light projecting means to the turbidity measuring device, (3) is the original light receiving means that passed through the turbidity measuring container, (
6) is a turbidity measurement container to hold the test liquid, (5) is a stirrer to uniformly stir the test liquid, (4) is a stirrer to rotate the stirrer, and (7) is the test liquid. , (8) is the original power meter, (91 is the ninth coaxial cable that transmits the electricity converted photoelectrically by the optical power meter, and 01m is the recorder.

Using the turbidity meter of the present invention, there is a method of photoelectrically converting the transmitted metal that has passed through the sample to be tested, and displaying the conversion pitch of the voltage generated by the rotation of the turbidity on an XY recorder in maximum and minimum values. How to read by the time of the peak value that appears,
It can be displayed using methods such as displaying changes in frequency.

Furthermore, by using the turbidity meter of the present invention, the turbidity of a sample can be measured under uniform conditions, and the amount of light transmitted through the same window that enters and exits the measurement container can be measured. This allows measurements to be taken without being affected by noise such as dirt on the measurement container. Since the turbidity meter of the present invention uses an arithmetic circuit, it has the advantage of being able to measure the suspended matter in the liquid to be measured as if it were separated from the solvent.

Using the turbidity meter of the present invention, a 1000 degree carrion turbidity standard solution diluted by volume with water was used as the sample, and a glass container in the form of 2.5 x 2.5 x 3.0 ohm was used as the measurement container. The measurements were carried out in a dark room at 2DC, using glass fibers and fibers as means for projecting and receiving light from a light source. The measurement resolution was 5 degrees carllion.

〔Effect of the invention〕

In the conventional turbidity measurement method, when the test liquid is stirred to make the turbidity of the test liquid uniform, the turbidity measurement value has a large fluctuation range, making it impossible to accurately measure the entire turbidity. Although it is possible, the turbidity meter of the present invention uses a calculation method that effectively utilizes its field of view, so it is possible to accurately measure the turbidity of the test liquid without causing measurement errors due to vibration. Can be done.

Furthermore, even if the measurement window of the measurement container is dirty, the turbidity meter of the present invention does not simply measure changes in the amount of light, but uses a method that captures changes in the amount of light, so the effect is extremely small.

Furthermore, by using the original fiber as the means for projecting and receiving light from the light source, measurements can be made with a small amount of sample, and turbidity can be measured in narrow spaces without being affected by electrical noise. There is an advantage.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of the turbidity meter of the present invention. DESCRIPTION OF SYMBOLS 1... Light source, 2... Source fiber for light emission, 5... Optical fiber for light reception, 4... Stirrer, 5... Stirrer, 6... Measurement container, 7... Sample , 8...Power meter, 9...Coaxial cable

Claims (1)

[Claims] A container for measuring the turbidity of a suspension, a means for stirring the suspension in the container, a means for projecting light to the turbidity measuring device, a means for receiving light passing through the turbidity measuring container, and an analysis of the optical period of the amount of light received. A turbidity meter equipped with means for calculating and outputting.