CS224553B1 - Apparatus for measuring a cotact height between two substances,positioned one obove the other - Google Patents

Description

BACKGROUND OF THE INVENTION The present invention relates to a device for measuring the contact height of two superimposed media of controlled dielectric constants, previously determined in the laboratory. The device has at least two separate electrodes extending into the learning areas of both media and one common electrode.

Such measurements, important for determining geological conditions and conditions _? especially in underground mines ^ has been associated with considerable difficulties _r One of the major mountains fluctuation was the upper surface ^of me dia, which was a source of substantial bending, respectively. inaccuracy of the whole measurement. It was therefore often necessary to either maintain a constant level of the upper medium level or to immerse the entire electro-capacity measuring device below this level. Each of these measures was complex, difficult to implement and also costly. The end members of such a device are generally two electrodes. The immersion of even one of them caused problems not only with its electrical connection but also with fixing its position in the required, for each measurement different depth.

The above-mentioned disadvantages are overcome and the results of the invention are further refined by a device according to the invention having at least separate electrodes extending into the height regions of both media and a common electrode. SUMMARY OF THE INVENTION The first electrode is in its upper part covered by a capacitive shielding sheath and, together with the second electrode, is housed in a non-metallic casing forming their galvanic insulation against both media. The common electrode is located on the outside of the non-metallic

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224 553 of the container, in which the two media contacting the monitored interface are located. The first electrode is connected to the first input of the electrocapacity evaluation block, to which the second input is connected both the second electrode and the common electrode.

In the drawing, one example of a device according to the invention is shown schematically in front elevation.

This device consists of a vertical first electrode 10, the upper end 11 of which is connected to the first input 71 of the evaluation block 70: its lower end 12 extends below the minimum interface height M of both media A and B. whose upper end 21 is connected to the second input 72 of the evaluation block 70; its lower end 22 extends above the maximum height

Ml · interface M of both media A and B. max - _ -

Between the two electrodes 10 and 20 there is a tubular shielding sheath 40 which electrostatically shields the first electrode 10 along its entire length. This assembly is housed in a non-metallic housing 50 which forms its galvanic isolation against both ^of A and B.

Is the monitored area _? at least partially delimited by a non-metallic container 60, on the outer wall of which a common electrode 30 is applied; its height corresponds to the length of the first electrode 10. This common electrode 30 is connected to the second input 72 of the evaluation block 70.

This evaluation block 70 comprises known devices and therefore not described in detail. wiring * eg measuring capacitive bridges * with a pointing device, on which the total capacity C is visually detected or even remotely transferred

For the sake of clarity, at the left edge of the drawing, both media A and B are shown, coming together at the M * interface in its middle height position. It should be noted that the capacitance Cg between the first electrode 10 and the second electrode 20 is constant and is therefore excluded from further processing.

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On the right edge of the drawing, the elevation positions of the interface M _{9 are} drawn in double lines, either solid or dashed, and the elevation positions of the upper medium level A? Drawn in a simple line, either solid or dashed. It goes without saying that the height position of the lower medium level B always coincides with the height position of the interface M.

The measuring range of the drawn device, from the highest height to the lowest height M M _{Q of the} interface M, is given by the difference in lengths 50 elektr of the electrodes 10 and 20. The influence of the variation of the level

In capacity}

Measurement procedure: XX is used in the evaluation block 70 by means of known measuring devices of the bridge and the like. For a given arrangement of the electrodes 10 and 20, as well as for predetermined dielectric constants of both media A and B, the size of the total capacitance C is within the limits corresponding to the values of the measured capacitances C, resp. Cg f t are proportional to the desired heights M ^^, resp. M & monitored interface M.

The device according to the invention can be used in a number of technical fields in cases where a simple yet highly reliable determination of the height position of the interface M between two media A and B on the contacting surface M is required.

It is not necessary that both media be liquid. For example, it can also be sludge, sediments, various sands and the like. The regulation according to the invention is simple, easy to manufacture and easy to operate.

Claims (1)

SUBJECT OF THE INVENTION 224 553 Apparatus for measuring the contact height of two superposed media of different dielectric constants having at least two separate electrodes extending into the height regions of both media and a common electrode, characterized in that the first electrode (10) is capacitively overlapped in its upper part a shielding sheath (40) and, together with the second electrode (20), is housed in a non-metallic housing (50) forming their galvanic isolation against both copper (A and B), while a common electrode (50) is located outside the non-metallic vessel (60) in which there are both media (A and B) contacting the monitored interface (&!), wherein the first electrode (10) is connected to the first input (71) of the electro-capacity evaluation block (70), to whose second input (72) both the second electrode (20) and the common electrode (50) are connected. 224 593