SU614332A1 - Discrete level gauge - Google Patents

Description

one

The invention relates to the field of instrumentation and can be used, in particular, to measure the level of oil and oil products in confined spaces.

A discrete float level transmitter is known, which contains a permanent magnet on the float and magnetically controlled contacts located in a non-magnetic pipe and connected via resistors to the secondary device 11J.

A disadvantage of the known level gauge is the low level detection accuracy, since, if the magnetically controlled contacts are located close to one another, an impulse flow closes several of them at once. When magnetically controlled contacts are separated, the so-called dead occurs, in which no contact is closed and there is no information about the liquid level at the device output.

Also known is a discrete level gauge containing a float with a permanent magnet and a ferromagnetic shield, magnetically controlled contacts located in a non-magnetic tube, connected via AND, NOT logic, an encoder and a decoder to the secondary device 2.

However, design complexity and reliability are noted due to the large number of logic elements.

The aim of the invention is to simplify the design and increase the reliability of measurements.

This goal is achieved by the fact that a normally closed contact on the contact group, starting from the top, is connected to the moving contact of the next group, while the normally open contact is connected to the corresponding input of the encoder, and the moving contact of the upper contact group is connected to the power bus.

FIG. 1 shows the scheme of the proposed level gauge; in fig. 2 is a schematic diagram.

The proposed discrete level gage contains a float 2 with a permanent magnet 3 and a ferromagnetic screen 4 located on a non-magnetic pipe. In the pipe 1, magnetic-controlled contacts 5-25 of switching type are placed with a constant pitch. Normally open contacts of each group through diodes 26 are connected to output buses

27 of the encoder 28, which through the decoder 29 is connected to the secondary device 30. The movable contact, of each group, starting from the bottom, is connected to the normally closed contact of the subsequent group, and the movable contact of group 25 to the power bus.

Discrete gauge works as follows.

When the float 2 is located at the liquid level corresponding to the initial value, the magnetic flux of the magnet 3 blinks the normally open contacts of group 5. A signal appears that is fed to the corresponding input of the encoder 28. At the same time, the close contact 5 is opened. When the float 2 moves along the tube 1, the control magnetic flux of the magnet 3 closes a series of located magnetic contacts, for example, 7 and 8. However, in this case, the information signal goes to the encoder 28 only from pin 8, since the power supply does not go to pin 7 .

The output information received from the encoder 29 goes to the secondary device 30 and can be used for processing on computing devices or for visual reference,

The connection in the proposed level switch switching magnetically controlled

contacts according to the described scheme with the required accuracy of measurement greatly simplifies the design and increases its reliability, since there is no need to use a large number of AND and NOT logic circuits.

Claims (1)

1. US patent 3473381, cl. 73-313, 1969. 2, USSR Author's Certificate 469890, cl. 01 R 23/12, 1975. h-b.