JPH04238247A - Liquid particulate meter - Google Patents

Abstract

PURPOSE:To prevent the occurrence of a fluctuation due to the heat transfer from a measuring cell by spraying the purge air with a purge air means. CONSTITUTION:The purge air is sprayed to a measuring cell 1 formed with a light radiation area to a sample liquid with a purge air means 2 constituted of a pump 3, a filter 4 and a nozzle 5. For the temperature distribution when a sufficient quantity of the purge air is sprayed to the cell 1 at a constant flow, the temperature gradient of a high-temperature sample is formed between the inner wall and outer wall of the cell 1, and the temperature of the outer wall becomes near the air temperature. Air is rarely moved by the purge air near the surface of the cell 1 in view of the heat capacity, and no fluctuation occurs.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid particle meter, and more particularly, to a liquid particle meter that focuses on a liquid sample having a high temperature.

0002

[Prior Art] Conventionally, although it is not intended for high-temperature liquid samples, it has been used as an in-liquid particle meter, for example,
There is one shown in Publication No. 140044.

On the other hand, in the field of manufacturing electronics such as semiconductors, high-temperature cleaning water and high-temperature cleaning chemicals are used as cleaning means. The advantage of this increased temperature is that it increases the solubility of the medium liquid and increases the cleaning effect. Furthermore, Freon has recently been regulated, and interest in warm pure water as a substitute for Freon is increasing. Based on the above background, it is expected that there is a high potential market for submerged particle analyzers that can measure high-temperature liquid samples.

0004

[Problems to be Solved by the Invention] Conventional submerged particle meters have not been implemented that guarantee the measurement of high-temperature liquid samples. This has problems such as bubbles and the inability to obtain materials that can withstand high temperatures, but one major problem that remains unresolved is the problem of fluctuations caused by the temperature difference between the measurement cell of the detection unit and the surrounding air. This is because it was hot. In other words, the air around the measurement cell where the laser beam irradiation area for the sample liquid is formed is in a stagnant state, and the temperature distribution when high temperature liquid is introduced into the measurement cell is caused by the temperature distribution on the outer wall of the cell, as shown in Figure 4. The temperature of is almost equal to the sample temperature,
The heat transfer from the outer wall of the cell to the surrounding air will be accompanied by fluctuations.

[0005] In the case of an in-liquid particulate meter using light, such as a light scattering method, such fluctuations cause adverse effects such as an increase in noise because the refractive index of air molecules changes randomly.

The present invention has been made to solve the above-mentioned problems, and its object is to provide a submerged particle meter that can prevent fluctuations due to heat transfer from a measurement cell.

[0007]

[Means for Solving the Problems] A submerged particle meter according to a first aspect of the present invention is provided with means for blowing purge air at a constant flow rate onto a measurement cell.

[0008] Furthermore, the in-liquid particle meter according to the second invention includes:
An envelope is provided around the measurement cell via an insulator to form a double structure, and the space between the double structures is a vacuum.

[0009]

[Operation] In the first aspect of the present invention, since purge air is blown onto the surface of the measurement cell, the air temperature near the surface of the measurement cell hardly changes from the viewpoint of heat capacity.

Furthermore, in the second invention, since the measurement cell is surrounded by a vacuum, no fluctuation occurs.

[0011]

[Embodiment] Fig. 1 shows an embodiment of the first invention, in which a measuring cell (1
) includes a pump (3), a filter (4), and a nozzle (5).
).

With the above configuration, when a sufficient amount of purge air is constantly blown onto the measurement cell (1) at a constant flow rate by the purge air means (2), the temperature distribution will be as shown in FIG. 2. As can be seen from FIG. 2, the temperature gradient when a high temperature sample is passed is mainly formed between the inner and outer walls of the cell, and the temperature of the outer wall of the cell is very close to the air temperature. Since a sufficiently large amount of purge air is blown onto the surface of the measurement cell (1), there is almost no fluctuation in the air temperature near the cell surface in terms of heat capacity, and therefore no fluctuation occurs.

Furthermore, by using clean air as the purge air, contamination of the outer surface of the cell can be prevented as a secondary effect.

FIG. 3 shows an embodiment of the second invention, in which an insulator with low thermal conductivity (
6) to form a double structure, and the space (8) of this double structure is evacuated.

With the above configuration, fluctuations are caused by the density and density of air molecules generated with heat conduction, but since the area around the measurement cell (1) through which the liquid flows is a vacuum, there is no possibility that the sample liquid is at a high temperature. However, no fluctuation occurs.

However, the measurement cell (1
) is not surrounded by a vacuum, so fluctuations occur. However, since this part is far away from the optical path of the laser beam, it does not pose a problem for particle detection.

[0017]

Effects of the Invention As is clear from the above description, the first aspect of the present invention is to blow purge air onto the measurement cell using purge air means, and the second aspect of the invention is to By forming a vacuum layer with a double structure, both prevent fluctuations due to temperature differences between the measurement cell and the surrounding air, improving measurement reliability even with high-temperature liquid samples. .

[Brief explanation of the drawing]

FIG. 1 is a side view of essential parts of an embodiment according to a first aspect of the present invention.

FIG. 2 is a temperature distribution characteristic diagram.

FIG. 3 is a sectional side view of a main part of an embodiment of the second invention.

FIG. 4 is a temperature distribution characteristic diagram in a conventional submerged particle meter.

[Explanation of symbols]

(1)...Measurement cell, (2)...Purge air means, (
6)...Insulator, (7)...Outer enclosure, (8)...
...vacuum space.

Claims (2)

[Claims] 1. An in-liquid particulate meter comprising: a measurement cell in which a light irradiation area for a sample liquid is formed; and purge air means for blowing purge air at a constant flow rate onto the measurement cell. 2. A measuring cell comprising: a measuring cell in which a light irradiation area for a sample liquid is formed; and an envelope provided on the outer periphery of the measuring cell via an insulator; An in-liquid particulate meter that creates a vacuum in the space.