JPS61240122A - Apparatus for reading indication value of liquid-level meter - Google Patents

Abstract

PURPOSE:To make it possible to easily and automatically read the indication of a liquid-level meter even when there is no large difference between transmissivities of a liquid and air, by utilizing the refraction of light at the boundary surface of the liquid and air generated by the surface tension of the liquid. CONSTITUTION:The light irradiated from a light source 5 is allowed to linearily irradiate the section A-C of a liquid-level meter 1 along the side surface of the liquid-level meter 1 by an optical fiber bundle 4. When the parallel light component among the rays of light transmitted through the boundary surface of a liquid 2 and air and the vicinity of the wall surface of the liquid-level meter 1 at this time is considered to be divided into the light A transmitted through the range free from the liquid 2 of the liquid-level meter 1, the light B transmitted through the boundary surface and the light C transmitted through the range filled with the liquid 2, both rays of light A, C transmits through the boundary surface of substances having different refractive indice but, because transmitted to the direction at right angles to the boundary surface, respective rays of light straightly advance to be reflected by a reflective plate 3 and the reflected rays of light are incident to optical fiber bundle 6. However, the advance direction of the light B does not become parallel to the boundary surface because the boundary of the liquid 2 and air comes to a curved surface by the surface tension of the liquid 2 and the indication of the liquid-level meter 1 can be easily read.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention provides self-control (second reading, The value of gJIRp is related to honest C2.

・ [Technical background of the invention and 7 problems] General (at the time of completion of the 2nd hydroelectric power plant or the completion of renovation work (2)
Comprehensive testing is conducted in the presence of the component manufacturer and purchaser.As a result of this witnessed testing, the Record and submit the readings of each meter, such as a pressure needle that detects the amount of expansion, a straight needle, or a transparent tube type liquid level gauge.

In this case, it is often necessary to read and record the readings of a large number of measuring instruments at the same time.
Many do not have a function to convert the indicated value into an electrical signal.

Therefore, for this reason, it is necessary to have a large number of personnel (the witness test will be carried out after all construction has been completed, so it is difficult to secure personnel at this point). , and - measurements are completed in a short period of time (= completed, but witnessed tests and measurements related to witnessed tests are often carried out over a relatively large number of times, which is disadvantageous in terms of labor saving.Father, Since humans are the ones who read the readings from the measuring instruments,
It had the disadvantage of having a certain amount of WR and SP.

In view of the above problems, a method of irradiating the liquid level gauge with light, optically detecting the difference in the amount of transmitted light or reflected light between the liquid and the air to be detected, and converting the difference into the 1@air signal (2) is proposed. However, according to this method, there must be a large difference in transmittance or reflectance between the liquid to be detected and the air. Transmission "4 (2) There is no large amount and it is difficult to detect the liquid level. Also, -16r, l2 The liquid that is the object to be detected has a higher refractive index than air, and the liquid level gauge is often cylindrical, so
Inside the liquid level gauge (= When liquid enters, it acts like a lens, condensing the incident source. Therefore, the irradiation angle of the light that is irradiated regardless of the amount of transmitted source, output, and reflected light amount.

The distance to the liquid level gauge, the distance between the receiver and the liquid level gauge (therefore,
Transmittance is smaller than air (despite the two.

A knife that is stronger after passing through the liquid part.
However, there were drawbacks such as the tJl and directivity of the thread removal device being difficult and impossible to standardize.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a device for reading liquid level gauge readings in place of human eyes and eyebrows.

[Key points of invention]

The direct reading device of the present invention (2) indicates that the surface tension of the liquid (2) causes the interface between the liquid and air to be disturbed near the wall surface C2 of the level gauge. Utilizing the phenomenon that the light emitted in the perpendicular direction (two directions) is refracted at the disturbed boundary (two) and does not travel straight, and the amount of light thereafter decreases, this point is reflected by the light of an image sensor/IIE transducer (: It is characterized by converting the yp' gas signal and reading the liquid level.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIG. In other words, 's1 diagram (2) 1 is a cylindrical liquid level gauge made of a translucent material such as glass or acrylic, 2 is the liquid to be detected, and 3 is a reflector that measures the normal liquid level. 4 is a bundle of optical fibers for irradiating light to the liquid rki gauge. The level of the lake is measured by the liquid level gauge (
5 is a light source, and a bundle of optical fibers 4 (
06, which allows two strong lights to enter, is a straight line on both shoulders (= a bundle of optical fibers bundled side by side, and the side facing the liquid level gauge C is shown in Fig. 2, parallel to the bundle 4 of optical fibers (2, and the interval between them is fixed to be very small. 7 is a condenser lens, and the image sensor 80 lights up the image on the intensified surface of the bundle 6 of optical fibers. The image sensor 8 may be a photodiode. 9 controls the image sensor 8 and forms an image on the sensitive part.
8 is an electronic circuit which amplifies the signal from 8; 10 is an electronic circuit 9;
A signal from the liquid level gauge (a signal indicating the level of the liquid level on the liquid level gauge).

The operation of the level gauge reading device constructed in this manner will be explained as follows. (2) The liquid level Mtl is irradiated in a straight line (2) between A and C of the liquid level Mtl. Regarding the parallel light component of the light, light A passes through the area of the liquid level gauge 1 where there is no liquid 2, and light B passes through the boundary surface.

Three pieces of light C that pass through the area filled with liquid 2. When considered separately, light A and C both pass through the interface of substances with different refractive indexes, but both of them pass through the interface of substances with different refractive indexes. In the direction perpendicular to the other light (because it passes through two directions, each light travels straight,
The bundle of optical fibers 6 (two beams) is reflected by the reflecting plate 3. However, the source B that passes through the interface between the liquid 2 and air is Since the boundary between and air is a curved surface, the direction of regression of light B is with liquid 2?
! The boundary surface of air (= not parallel. Ordinary liquids have a higher refractive index than air, and light B is refracted as shown in Figure 42 (= shown) and cannot travel straight. This is because the source reflected by the reflecting plate 3t is also the same. Therefore, the brightness and darkness of the light at the end face of the original fiber bundle on the liquid level gauge 1 side is as shown in Figure 3 (a) (2). The other end of the fiber bundle 6 (2) is transmitted, and the condensing lens 7 (2) forms an image of the sensitive area on the image sensor 8. However, the signal is outputted as a serial signal corresponding to the image sensor sensitive part It4.

The electronic circuit 9 amplifies this signal and converts it to Z II ($3
tb)) L, then transfer to display I. The display 10 detects the part of the signal υB shown by s2, converts it into two direct currents and two A signals, and displays the first part of the signal.

〔Effect of the invention〕

As explained above, this is the perfect outfit! (In = table 1i1i bending force of liquid (Also, it is possible to easily read the indicated value of the liquid level gauge.Also, since the magnetic signal (two variables) can be easily read, the indicated value of other measuring instruments that are widely scattered can be easily read. It can be attached to electrical signals and measured internally, allowing for monitoring and recording (reducing the labor required for 62M
It is effective. Note that this method (a) does not require any modification to the inside of the liquid level gauge, so it can be installed to the existing g, surface needle (ii).

[Brief explanation of drawings]

Fig. 1 is a configuration diagram of a liquid level gauge indicator 1 reading device according to an embodiment of the present invention, Fig. 2 is an enlarged view of part ■ in Fig. il1, W,
Figure 3 tal is a curve diagram showing the vertical brightness and darkness on the liquid level gauge 1141 surface, Figure 3 + b) is a curve diagram obtained by converting Figure 3 il) into a drowsiness signal and converting it into a 21 straight line. 4 Figure C $ 1 Figure (7
) is an elevational view along the line IV-IV. 1...Liquid level gauge 2...Liquid 3...Reflector plate 4...Optical fiber bundle 5...Light source 6...
Original fiber bundle 7...Condensing lens 8...Image sensor 9...Pako circuit IO...Display device.

Claims (1)

[Claims] A liquid level gauge having a light reflecting part on a part of the wall of the liquid surface part; an optical fiber bundle having end faces arranged in a direction perpendicular to the liquid surface on the opposite side of the light reflecting part; and a part of this optical fiber bundle. A liquid level gauge reading device comprising: a light source that enters light at one end; and a photoelectric converter and a display connected to the other end of the other part of the optical fiber bundle.