SU832344A1 - Liquid level measuring device - Google Patents

Description

(54) DEVICE FOR MEASURING LEVEL OF LIQUID

one

The invention relates to a device for measuring the level of a liquid and can be used to determine the level of a liquid in tanks with an overpressure, for example, in systems for preparing detergent solutions in laundry factories, etc.

A measuring device for determining the properties of an electrically conductive liquid is known, which contains a transformer sensor with field windings and measurement devices and a circuit for setting up the elements of the device that eliminate measurement errors 1.

The drawback of the device is the complexity of the design and the limited use, since the device works only with electrically conductive liquids.

The closest to the proposed technical essence is a device for measuring the level of a liquid, which contains a float located in a housing immersed in a controlled fluid, a transformer sensor, the measles of which is connected to the float, and a recording device 2.

A disadvantage of the known device is that it has a relatively low accuracy and a narrow range of variable fluid levels.

Low accuracy is primarily due to the lack of means for adjusting and adjusting the device during its operation, depending on what the density of the medium is in the variable volume, its temperature, etc. The narrowness of the range of applicability is explained by the fact that this device Q cannot be quickly rebuilt to work with drastically varying ranges of fluid levels, since the accuracy of a transformer sensor varies with different operating modes.

The purpose of the invention is to improve the accuracy and expand the scope.

Claims (2)

This goal is achieved due to the fact that the device is equipped with a compensating spring located between the end of the float and the housing, and two additional electrical circuits are inserted into the electrical circuit of the transformer sensor, each consisting of a diode and a potentiometer and connected respectively to the primary and secondary coils of the sensor, at the same time, the moving contacts of the potentiometers are electrically connected to the recording device. FIG. 1 shows the proposed device, a general view; in fig. 2 - electrical device diagram. The device contains a float 1, a measles 2, a spring 3, a kbzhukh 4, a housing 5, windings 6 and 7 of the transformer, a housing 8, a connector 9, a gasket 10 installed in the lid 11 of a tank filled with liquid, a recording device 12 and a cable 13, as well as CMeHHbie loads 14. The electrical circuit, in addition to the recording device 12, the primary winding 6, the secondary 7 and the core 2 also includes two chains consisting of diodes 15 and 16 and potentiometers 17 and 18. Points a and b in the diagram are the ends of the transformer coils. The movable contacts of the potentiometers are connected to a recording device 12, for example, a milliammeter. The device works as follows. The displacement of the float 1 under the action of a varying liquid level causes the core 2 to enter the casing 4, on which the rolls 6 and 7 of the transformer are located. The resulting signal is fed through diodes 15 and 16 and potentiometers 17 and 18 to a recording device 12. At the same time, the signal to it is fed from the moving contacts of the potentiometers, the potentials of points a and b are taken to zero. Then the potential taken from the engine of potentiometer 18 depends on the position of the core (core 2) and the position of this engine itself. For a given position of the slider, the potential difference on the device 12 varies depending on the course of the core. The position of the slider of potentiometer 18 determines the amplitude of the potential difference when the core is moved. This is exactly what allows the instrument to align with the movement of the core, thus improving measurement accuracy by changing the position of the slider of potentiometer 18. Potentiometer 17 allows to compensate the initial voltage, i.e., the position of its slider, set the instrument to zero with greater precision 12. In this way, the device can be adjusted at the initial position, i.e., potentiometer 17 controls the range of measured liquid levels and thereby improves the technological capabilities of the device. The replaceable weights 14 are intended to ensure the operation of the spring 3 in the mode in which it is not stretched in the middle position of the liquid level in the tank. Apparatus of the Invention A device for measuring the level of a liquid, comprising a float located in a housing and immersed in a controlled liquid, a transformer sensor, the measles of which is connected to the float, and a recording device, characterized in that, in order to increase accuracy and extend the range of application, the device is equipped with a compensating a spring located between the end of the float and the housing, and the electrical circuit of the transformer sensor includes two additional electrical chains, each consisting of diode and potentiometer and connected respectively to the circuit of the primary and secondary sensor coils, while the movable contacts of the potentiometers are electrically connected to the recording device. Sources of information taken into account in the examination 1.US Patent H 4144756, cl. G 01 F 23/00, 03.20.79. 2. US patent number 2911828, cl. 73-290, 10.11.59 (prototype). ./ FIG. 2