JPS585949Y2 - Low pressure gauge - Google Patents

Description

[Detailed explanation of the idea] This invention relates to the structure of a micropressure gauge.

More specifically, the present invention relates to a micropressure gauge having a structure in which the bottoms of triple tanks are connected by communicating pipes, and the differential pressure on the liquid level is read at the communicating pipes.

This device is based on the micropressure meter previously filed by the applicant in Japanese Patent Application No. 53-31309, which is a double tank with an inner tank and an outer tank connected at the bottom by a communicating tube kept substantially horizontal. Improvement of a micropressure gauge configured so that two types of immiscible liquids are injected into a communicating pipe part so that an interface is created, and the interface that moves due to the pressure difference between the inner tank and the outer tank is read in the communicating pipe part. The object of the present invention is to provide a micropressure gauge whose measurement range can be further expanded than that of a double tank micropressure gauge.

In other words, the micro-pressure meter applied in Japanese Patent Application No. 53-31309 is too sensitive to micro-pressure, so when a rather large differential pressure occurs, it scales out in the communicating pipe, so it is used in conjunction with a normal tilt manometer. There was an inconvenience that had to be had.

The present invention is intended to compensate for such drawbacks, and is explained using drawings as shown in Fig. 1 (Fig. 3) and Fig. 2.
As shown in Figure 4, the structure of the micropressure gauge of the present invention consists of a triple tank consisting of an outer tank 1, an intermediate tank 2, and an inner tank 3, and a valve 4 with a nozzle for introducing measurement gas at the top of each tank. , 5 and 6
To install them, the communication pipes I are taken out from the bottom of each type and connected to each other.

For example, in a micropressure gauge with the structure shown in Figure 1 (Figure 3), one liquid 1 is injected into the outer tank 1, the other liquid 2 is injected into the intermediate tank 2 and the inner tank 3, and the intermediate tank 2 and the inner tank 3 are filled with one liquid 1. A valve 8 and a valve 9 are attached to the communicating pipe section taken out from the pipe.

In addition, in the micropressure gauge with the structure shown in Figure 2 (Figure 4), the intermediate tank 2
One liquid is injected into the outer tank 1 and the other liquid is injected into the inner tank 3, and a valve 8 is inserted into the communicating pipe section taken out from the outer tank 1 and the inner tank 3.
' and 9' are attached.

In this way, by switching the valves 8 and 9, or the valves 8' and 9', any two of the three tanks can be used in combination with another tank at the same time or by switching between them. The configuration is such that three combinations can be obtained depending on the object to be measured.

H The magnification ratio of the micropressure gauge of the present invention is p, the cross-sectional area of the conduction tube is a; the density of liquid 1 is ρ□, the density of liquid 2 on the other three sides is ρ2, the area of the pressure-receiving surface of liquid 1 is A□, If the area of the pressure-receiving surface of the liquid 2 is A2, it can be expressed as A2 when the communicating pipe section is kept substantially horizontal.

As is clear from the above equation, even if the density of the two types of liquids and the cross-sectional area of the conduit are constant, the expansion ratio can be changed by changing one of the pressure receiving areas of the two types of liquids. I can do it.

Therefore, in the micro-pressure gauge of the present invention, the combination of the micro-pressure gauge with the structure shown in Figure 1, that is, the outer tank 1 and the intermediate tank 2 or inner tank 3, can be obtained. The cross-sectional area ratio of the outer tank 1 and the inner tank 3 is calculated by the cross-sectional area ratio of the outer tank 1 and the inner tank 3. By appropriately changing the cross-sectional area ratio, a desired ratio of enlargement can be obtained.

Therefore, by setting the cross-sectional area of the three tanks to an appropriate size, the micropressure gauge of the present invention can increase the magnification ratio of the three magnification ratios obtained by using two tanks at the same time by 10 times. It is possible to do more than this.

For example, if one micro-pressure gauge of the present invention is configured to have a magnification of 100 times and 10 times by combining three tanks, it will be more than 100 times as large as the conventional micro-pressure gauge filed in Japanese Patent Application No. 31309-1983. A single micropressure meter can have both the measurement performance of a device with a high magnification such as a manometer and a device with a magnification of about 10 times such as a tilted manometer.

Therefore, any variation in differential pressure can be measured with a single micro-pressure gauge of this invention without using two types of pressure gauges when actually measuring pressure, especially when using a micro-pressure gauge in a portable manner. It is convenient for

The materials of the various valves and communication pipes of the present invention are not particularly limited, and include glass, glass whose inner surface is treated with silane, quartz, polyethylene, polypropylene, vinyl chloride resin, acrylic resin, polycarbonate, trifluoroethylene resin, and tetrafluoroethylene resin. Polyethylene resin, hexafluoroethylene resin, or the like can be used.

However, it is desirable that the material of the communication pipe be substantially transparent;
Fluorinated ethylene resin is preferred in terms of adhesion to liquids, strength, transparency, corrosion resistance, and the like.

In this invention, two types of liquids are injected into each type of liquid, but the smaller the difference in specific gravity between the two types of liquids, the smaller the measurement error, so if water is used for one liquid, anisole is used for the other organic liquid. For example, a mixed solution of chlorobenzene and xylene can be used as the organic liquid to minimize the difference in specific gravity with water.

[Brief explanation of drawings]

1 and 2 are vertical sectional views of the micropressure gauge according to the present invention, and FIGS. 3 and 4 are horizontal sectional views.

Claims (3)

[Scope of utility model registration request] (1) In a triple tank consisting of an inner tank, an intermediate tank, and an outer tank whose bottoms are connected by a communicating pipe kept substantially horizontal, a valve for introducing gas is provided at the top of each tank, and Two types of liquids that do not mix with each other are injected into two of the triple tanks and the remaining tank, and a switching valve is installed at the bottom of the tank so that the two tanks can be used simultaneously or by switching. A micropressure gauge configured to read the interface that moves due to the pressure difference applied to various liquid levels in the communicating pipe section. (2) A micropressure meter as described in Claims (2) in which one of the two liquids is water or an aqueous solution and the other is an organic liquid that does not dissolve therein. (3) The micropressure gauge according to claim (2), wherein the organic liquid is anisole.