JPS586887B2 - liquid prism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention comprises at least one transparent sealed entrance and exit window and a cell containing a liquid in which a transparent float device is placed. It concerns the liquid prism formed when directing the liquid.

The property of a liquid to always maintain a horizontal plane even when the container is tipped is known and is used in particular when the height of a filled liquid level has to be measured and when a horizontal or vertical reference plane has to be determined.

Thus, for example, an optical level has a refractive index nDf -1.
It is made up of two superimposed glass cells partially filled with liquid No. 5, so that the inclination of the level corresponds to the angular deviation from the optical axis.

The structure of the level does not cause any problems as long as the cell has a diameter of 30 mm or less; A great challenge arises when the design has to be scaled down.

There is a direct relationship between the deviation of the liquid level from the horizontal position and the magnitude of the surface tension in the cell liquid and the energetic parameters of the material making up the cell walls.

In order to eliminate the capillary action on the liquid surface that gives rise to lenticular surfaces, various methods have been proposed to achieve a horizontal liquid surface in even the smallest cells.

However, they suffer from the following drawbacks.

1. When the slope of the inner edge of the cell and the liquid level are at an angle of about 00, the tolerance and volume are each so small that finding the correct volume of cell liquid becomes difficult, if not impossible. The fabrication of each of the necessary inserts and floats is very complex.

One, even when cylindrical cell inserts are made of low surface energy polymers, only high surface tension liquids are suitable, so organic liquids are rarely available or
Acceptable only as an aqueous solution.

Due to the hysteresis that occurs in such solutions, it is not possible to establish a constant angle of contact between the liquid level and the cell wall.

1. When a cell insert made of a low surface energy polymer has a sloped wall surface, it is difficult to set the contact at a constant angle because the hysteresis effect cannot be completely eliminated.

The angular embodiment of the contact is influenced by temperature, just as in the previous case.

When the float is placed above the cell liquid in a sealed cylinder type, hysteresis is eliminated, as is the temperature effect on the angle of contact acquisition, but other drawbacks arise, which are present in cells with inner diameters smaller than 10 mm. becomes particularly large.

Glass float (σ; 7 5erg 7crit)
If the float is easily wetted, the float must protrude significantly above the liquid to prevent its cover from reaching the liquid.

Also, if a low mass float is employed, other disadvantages may arise due to friction between the float and the cell wall, which can hinder operation, and the very dense float material, which requires a relatively large volume of float. arise.

Therefore, the object of the present invention is to eliminate the above-mentioned drawbacks.

It is a further object of the invention to provide a liquid prism which is stable in operation even when used, for example in mobile equipment and/or at extreme temperatures.

The invention therefore consists of a cell containing a liquid in which at least one sealed transparent entrance and exit window and a transparent float are arranged, the liquid having a refractive index nDf of 1.
4<nDf<1. 5 and the density is ρ, and the float is at least 0.5 mm thick and its diameter is 0.5 to 2.0 mil smaller than the inner diameter of the cell.
) is a plane-parallel disk of a synthetic material of less than 100 m, and the refractive index nDs of the synthetic disk is i. 3
< n Ds < 1.6 and its density ρ is ρ ≤ ρ, or ρ = ρ when extremely low surface energy disks are used, and the composite disk is lower than the liquid. The present invention relates to a liquid prism for directing light beams in any direction, which is characterized by having surface energy.

This prism is advantageously composed of two chambers, and the value of the surface energy σ5 of the composite disc ( erg /c
m') is the value of the surface tension σf of the liquid (dyn
/cm).

That is, the cohesive force between molecules of the liquid is preferably greater than the adhesive force between the liquid and the synthetic disk.

The limiting angle of the conductor is then advantageously set to (σ5<σf).

Unlike conventional prisms, the prism is made up of two chambers, so it is very small and does not take up much space, and since the chambers are equally configured, the light rays are shifted by the same amount in each chamber. , in other words, it is shifted by twice the amount, making it possible to compensate for the tilt technically easily.

Preferably, the material of the prism walls has a higher surface energy value than the float, such as glass or metal.

When these conditions are maintained, the liquid being raised on the prism wall is held by the composite disk so that the liquid is always centered without friction and measurement errors are eliminated.

The materials of choice for the prismatic force bar and float are polyolefins, especially polyethylene or polypropylene.

Because this material has a low surface energy (25-30 erg/cm) at a suitable refractive index and density, there is no risk of wetting the material.

Polyolefins allow the use of pure organic liquids.

In order to eliminate disturbances caused by liquids adhering to the prism cover, the prism cover can of course be made of a transparent low surface energy synthetic material, or of a transparent material coated with a low surface energy synthetic material of any refractive index. Must be made.

The choice of cell fluid is influenced by the synthetic material used.

According to the invention, the refractive index n D=1. 3 to 1,6 polymeric synthetic materials are optimal.

Some important para-tables of synthetic materials used are:
Indicates a suitable cell liquid that meets the requirements.

Achieve a low freezing point to enable operation even at low temperatures.

The density, refractive index and freezing point of the mixed liquid can be set to arbitrary values by adding an appropriate inorganic salt.

For this purpose, the chemicals listed in the following table are particularly suitable.

With the invention, the liquid prism can be made small in size and work under high pressure due to movement and under extreme temperatures.

If the synthetic material is properly chosen, there will be no friction between the prism wall and the float due to the non-wetting of the top surface of the float and the positive centering of the float.

Next, a description will be given according to an embodiment shown in the drawings.

The prism with an XX axis consists of a cover 2, a base 3 and a wall 1.

Inside the prism, there is a night body 7, such as formamide, for example.
A partition wall is provided separating two chambers 5, 6 containing 8.

Discs 9, 10 made of synthetic material are arranged in respective chambers 5, 6.
placed on the surface of the liquid inside.

Magnetic devices 11, 12 and 13,1 all of equal polarity
4 is employed to hold the discs 9 and 10 so that they are not distorted.

Magnetic device 11.13 fixed to each of the disks 9, 10
are respectively located inside the wall 1 between the magnetic devices 12 and 14.

Due to the inherent surface energy of the liquids 7, 8 within the wall 1 and the composite discs 9, 10, the liquids 7, 8 crawl upwardly between the wall 1 and the composite discs 9, 10 without wetting the disc surface.

The materials selected for the individual components and their properties are shown in the table below.

It will be seen from the table that due to the azimuth accuracy that has to be met, in the example embodiments, the tolerances in the refractive index are relatively narrow.

Its refractive index nDf has a narrow tolerance nDf=1,50±0.0
1 is the condition.

The illustrated prism is used for passing light in the XX axis direction.

That is, rays of light which must be directed in a vertical or predefined direction pass through the prism substantially parallel to the axis X--X.

However, the invention naturally also includes prisms in which the transmitted light beams are reflected.

Therefore, the prism is not limited to a cylindrical shape; for example, the longitudinal section of the prism may be rectangular, triangular, or trapezoidal.

The magnetic device for supporting the composite disc to prevent distortion may be replaced by a mechanical system consisting of protrusions and groups.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of the prism. FIG. 2 is a plan view of the float disk. 1... Wall, 2... Cover, Total...
・Base, 4... Partition wall, 5, 6... Chamber, 7, 8... Liquid, 9, 10... Disk, 11, 12, 13,14...Magnetic device.

Claims (1)

[Claims] 1 Consists of at least one sealed transparent entrance window and exit window and a cell containing a liquid in which a transparent float is arranged, the liquid having a refractive index nDf of 1
．． 4 < n D (< 1.5 and has a density of ρf and whose float is at least 0.
5 mm thick and 0.0 mm thicker than the inner diameter of the cell.
A planar parallel disk of synthetic material that is 5 to 20 mm smaller in diameter, and the refractive index of the synthetic disk n D 8
is 1. 3<nDs<1. 6 and the density force ρS≦ρf, or when an extremely low surface energy material is employed, ρ5 = ρf, and the composite disk is characterized by having a lower surface energy than the liquid. A liquid prism that directs light rays in any direction. 2. The liquid prism as claimed in claim 1, wherein the surface energy of the composite disk is lower than the surface energy of the prism wall. 3. The liquid prism as claimed in claim 1 or 2, wherein the prism cover is made of a transparent low surface energy synthetic material or a transparent material coated with a low surface energy synthetic material satisfying the required refractive index. 4. A liquid prism as claimed in any one of claims 1 to 3, wherein an inorganic salt is added to the liquid to change the refractive index, density and score. 5. The liquid prism as claimed in any one of claims 1 to 4, which is provided with a device for preventing distortion of the composite disk.