JPH0432604Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an improvement in the structure of a conductivity measurement cell used to measure the conductivity of a liquid such as a solution.

(Prior Art) Conventionally, conductivity measurement cells having a large cell constant, for example, those having a nominal cell constant of about 10.0, have a structure as shown in FIG. 2.
That is, cylindrical liquid passage pipes 2 and 3 are arranged horizontally opposite to the support pipe 1, and platinum black is deposited and formed on the surface of a cylindrical metal such as a platinum plate inside the pipe. Providing electrodes 4 and 5 as a pair,
When this is immersed in the test liquid, the conductivity of the test liquid is determined from the total surface area of electrodes 4 and 5, the cell constant determined by the distance between the two electrodes, and the reciprocal of the electrical resistance between the two electrodes. It is something.

(Problems with the prior art) In such a conventional conductivity measuring cell, the liquid passage tube sections 2 and 3 protrude on both sides of the support tube section 1, so that the entire electrode sensing end is immersed in the sample liquid. Since the sample liquid is immersed in the liquid, the amount of test liquid required is relatively large.Furthermore, if air bubbles adhere to the liquid passageway or the electrode surface, the effective surface area of the electrode decreases, resulting in measurement errors. In cells, the electrodes are cylindrical and small, making it difficult for air bubbles to adhere to them.

(Means for solving the problems) The present invention eliminates the above-mentioned drawbacks of the conventional example, enables highly accurate measurement, and reduces the amount of test liquid required for measurement. A conductivity measurement cell is provided.

(Structure and Examples) The conductivity measuring cell according to the present invention has one side of the electrode plate in close contact with the inner wall surface of the liquid passage pipe, and the liquid passage pipe section is arranged in a V-shape with respect to the support tube. In particular, the surface area of the cell detection portion immersed in the test liquid, that is, the required amount of the test liquid, can be reduced to a small amount.

FIG. 1a is a partial cross-sectional view of a structure of an embodiment of a conductivity measuring cell according to the present invention. In addition, FIG. b shows a cross-sectional view similarly seen from the bottom surface of the cell.

In the figure, the electrodes 4 and 5 are disposed with one side in close contact with the inner wall surface of the liquid passage pipes 2 and 3, and are made of a platinum plate with platinum black adhered to the surface.

The liquid passage pipes 2 and 3 are welded or bonded to the support tube 1 in a V-shape, and the electrode lead wires 6 and 7 are enclosed in the welded or bonded portions and led upward from within the support tube. Although this example has a nominal cell constant of 10.0, other constants can be obtained depending on the dimensions of the electrode plate, support tube, and liquid passage tube.

(Function) In the conductivity measurement cell configured in this way, since the electrodes 4 and 5 are in close contact with the inner walls of the liquid passage pipes 2 and 3, there are no obstacles in the pipes, and therefore there is no possibility of damage. Even if air bubbles occur in the test liquid, they will not remain in the liquid passage and
Since the liquid passes upward, there is no change in the effective surface area of the electrode plate.Furthermore, since the liquid passage pipe sections 2 and 3 containing the electrodes are arranged in a V-shape with respect to the support tube 1, the test liquid The area occupied by the cell in the container is reduced, and the amount of test liquid required can be reduced.

(Effects) By adopting the present invention, air bubbles do not remain in the electrode and liquid passage pipe, and there is no change in the effective surface area of the electrode.

By arranging the liquid passage tube containing the electrode in a V-shape with respect to the support tube, the cell can be fully inserted and immersed even if the test liquid container is small, so the required amount of test liquid can be reduced. .

There are other effects.

[Brief explanation of the drawing]

FIG. 1a is a partial cross-sectional view of the structure of an embodiment of the conductivity measuring cell according to the present invention. FIG. 2B shows a cross-sectional view as seen from the bottom of the cell, and FIG. 2 is a partial structural cross-sectional view showing an example of a conventional conductivity measuring cell of this type.

Claims (1)

[Scope of utility model registration request] In a conductivity measurement cell having a pair of detection ends with one electrode provided in the middle part of a cylindrical liquid passage, an electrode plate is provided with one side in close contact with the inner wall surface of the liquid passage, and the detection end A conductivity measurement cell is arranged so as to be held in a V-shape with respect to the support tube.