SU556340A1

SU556340A1 - Optical level gauge

Info

Publication number: SU556340A1
Application number: SU2178435A
Authority: SU
Inventors: Абрам Хаймович Гольберг; Анатолий Петрович Гришов
Original assignee: Предприятие П/Я А-7779
Priority date: 1975-10-07
Filing date: 1975-10-07
Publication date: 1977-04-30

Description

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Изобретение относитс к области техники измерени уровней и может быть иснользовано дл измерени уровн жидкостей, имеющих различную оптическую плотность.The invention relates to the field of level measurement technology and can be used to measure the level of liquids having different optical densities.

Известны оптические уровнемеры, содержащие источник света и фотоприемник, расположенные на противоположных сторонах сосуда, и показывающий прибор, св занный с фотоприемпиком 1.Optical level gauges are known that contain a light source and a photodetector located on opposite sides of the vessel, and showing a device associated with the photodetector 1.

Эти уровнемеры имеют недостатки, такие как невысока точность измерени и больша зависимость точности измерени от изменени оптической плотности среды, загр знени окон светопроводов и изменени напр жени питани .These level gauges have drawbacks, such as low measurement accuracy and a large dependence of measurement accuracy on changes in the optical density of the medium, contamination of the light guide windows and changes in the supply voltage.

Наиболее близким из оптических уровнемеров к изобретению по технической сущности вл етс уровнемер 2. Данный уровнемер содержит источник и фотоприемник, индикатор мутности, след щую систему, регистрирующий прибор, генератор электрических колебаний с электродами и пьезоэлектрические вибраторы, установленные в окнах световодов .The closest of the optical gauges of the invention according to the technical essence is gauge 2. This gauge contains a source and a photodetector, a turbidity indicator, a tracking system, a recording device, an oscillator with electrodes and piezoelectric vibrators installed in the optical fiber windows.

Однако такой уровнемер имеет невысокую точность измерени , обусловленную наличием больщого количества элементов и, соответственно , сложную конструкцию.However, such a level gauge has a low measurement accuracy due to the presence of a large number of elements and, accordingly, a complex structure.

Цель изобретени - повышение точности измерени и упрощение конструкции.The purpose of the invention is to improve the measurement accuracy and simplify the design.

Это достигаетс тем, что фотоэлектрический приемник выполнен в виде раснолол енны.х на одном уровне оптического клина, расшир ющегос кверху, и оптического стекла с наложенными на их грани под одним углом к световому потоку фотоэлементами, которые подключены к схеме преобразовани фототока, изготовленной в виде логарифмирующих усилителей, к выходам которых подключенThis is achieved by the fact that the photoelectric receiver is made in the form of a rasnolol ennyx on the same level of the optical wedge, expanding upwards, and optical glass with photoelectric cells superimposed on their faces at one angle to the light flux, which are connected to logarithmic amplifiers, the outputs of which are connected

блок разности, соединенный с одним из входов другого блока разности, на второй вход которого подано опорное напр жение.a difference unit connected to one of the inputs of the other difference unit, the second input of which is supplied with a reference voltage.

На фиг. 1 показана принципиальна схема фотоцриемника; на фиг. 2 - схема соединеПИЯ измерительных элементов; на фиг. 3 - принцип действи фотоприемника оптпческого уровнемера.FIG. Figure 1 shows a schematic diagram of a photocetum; in fig. 2 - connection diagram of measuring elements; in fig. 3 - principle of operation of the photodetector of the optical level gauge.

Оптический уровнемер состоит из сосуда 1 с жидкостью, установленных в окнах 2 источника света 3 и фотоприемника 4. Фотоприемник 4 выполнен в виде расположенных на одном уровне оптического клина 5, расшир ющегос кверху, и стекла 6, расположенного параллельно наклонной поверхности клина 5,The optical level gauge consists of a vessel 1 with a liquid installed in the windows 2 of the light source 3 and the photodetector 4. The photodetector 4 is designed as an optical wedge 5 extending upwards and located on the same level of the optical wedge 5,

Claims

with photodetectors 7 and 8, nalennyh on their faces, Photoreceivers 7 and 8 are connected to photocurrent converters 9 and 10, made B as log-amplifiers connected by outputs to difference unit 11, which through the second difference unit 12, to which the reference voltage is applied Woa, connected to the display device 13. Zfnefmener works as follows. The liquid level in vessel 1 darkens the photodetectors 7 and 8, dividing the area of each photodetector into an illuminated (above the liquid level) and a dark one (below the liquid level). When the level in the vessel changes, the illuminated and darkened areas of the photodetectors 7 and 8 change, resulting in a change in the output signal from the difference unit I. This signal is compared in the difference unit 12 with the reference lump / 7op. and a spread signal, proportional to the change in level, is applied to the indicating device 13. The zero value of the level is set by selecting the reference voltage Uon. measurements. This is due to the fact that the output signal from the photodetector 7 is compared with the signal from the photodetector 8. The output signal of the photodetector 7 depends both on the ratio of the illuminated and darkened areas, and on the optical density of the wedge located in front of the illuminated area. The output signal of the photodetector 8 depends only on the ratio of the illuminated and darkened areas. When subtracting one signal from another, all side factors affecting the measurement accuracy are excluded, since they act equally on both photodetectors. The output signal from the difference block And in this case contains the dependence of the illumination of the photodetector 7 only on the density of the optical wedge 5, which is proportional to the liquid level. Claims of the invention An optical level gauge comprising a source and a photoelectric iriam of light mounted on diametrically opposite sides of a vessel with a liquid, and a photocurrent conversion circuit connected to an indicating device, characterized in that, in order to improve the accuracy of measurement and amplification of the structure, a photoelectric receiver made in the form of an optical wedge razolozhenny at the same level, expanding to the top, and optical glass with photos superimposed on their faces at one angle to the light flux elements that are connected to the photocurrent conversion circuit, made in the form of logarithmic amplifiers, to the outputs of which a difference block is connected, connected to one of the inputs of the other difference block, to the second input of which a reference voltage is applied. Sources of information taken into account during the examination: 1.Litvak V.I. Photoelectric sensors in control systems, control and regulation. M., Iauka, 1966, p. 228-229, fig. 5.32.

2. Avt. St. No. 356471, cl. G 01 f 23/22, 1971 (irototi).

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FIG. I