RU2212635C1 - Float fiber-optical level indicator to check inleakage or outflow of liquid - Google Patents

Abstract

FIELD: instrumentation, check of emergency state in compartments of surface and underwater craft. SUBSTANCE: float fiber-optical level indicator has cylindrical tube oriented vertically which communicates with checked vessel, float, two light-emitting diodes and register located in vertical tube. Light guides come in the form of fiber coils optically matched with light-emitting diode and photodiode in interferometer. Photodiode is connected with output through amplifier to register. First fiber coil is positioned on tube bottom and second fiber coil is put on lower face of float. Register is manufactured in the form of frequency meter. EFFECT: ensured generation of pulse-frequency signal carrying information on amount and speed of outflow or inleakage of liquids into checked vessel. 2 dwg

Description

 The invention relates to the field of instrumentation and can be used to control the emergency state in the compartments of surface and underwater boats.

 A device [1] for a similar purpose is known, comprising a transparent outlet tube with a float located therein, an LED and several photodiodes located along the outlet transparent tube. A ray of light, reflected from the float, hits a particular photodiode, noting the level of liquid in the tank.

 The disadvantage of the analogue is the discrete nature of the controlled level values.

 Known float fiber-optic level gauge for controlling the outflow or leakage of liquid [2], adopted as a prototype and containing a vertically oriented cylindrical tube in communication with a controlled reservoir, and located in a vertical tube, a float and two fibers, optically matched with an LED and a photodiode connected to the output through the amplifier to the recorder.

 Light from the LED is reflected from the mirror element located on the upper end of the float, and enters the photodiode, the photocurrent from which is amplified and enters the recorder. In this way, leakage or leakage of fluid into the tank is controlled.

 The disadvantage of the prototype is the lack of a pulse-frequency signal at the output of the level gauge, which reduces the sensitivity of the device.

 The technical result obtained from the implementation of the invention is to eliminate this drawback of the prototype, i.e. providing at the output of the level gauge a pulse-frequency signal that gives information about the quantity and speed of the outflow or leakage of liquid into a controlled reservoir.

 This technical result is achieved due to the fact that in the known fiber-optic level gauge for controlling the outflow or leakage of a liquid containing a vertically oriented cylindrical tube communicating with a controlled reservoir, and located in a vertical tube, a float and two optical fibers optically matched with an LED and a photodiode, the connected output through the amplifier to the registrar, the optical fibers are made in the form of fiber coils, optically coupled to an interferometer, while the first fiber coil the cabinet is located at the bottom of the pipe, and the second is at the lower end of the float, and the recorder is made in the form of a frequency meter.

 The invention is illustrated in the drawing, in Fig.1 which shows the mechanical circuit of the level gauge, and in Fig.2 - the optoelectronic circuit of the control and recording part of the level gauge.

 The level gauge contains (Fig. 1) a vertically oriented cylindrical pipe 1 communicating with a controlled reservoir (not shown in the drawing) by means of a branch pipe 2.

 In the vertical tube 1 there is a float 3, on the lower end of which a first fiber coil 4 is fixed. At the bottom of the pipe 1 there is a second fiber coil 5. Fiber coils 4, 5 are optically matched to an interferometer, for example, Zehnder-Mach (figure 2) with an LED 6 and a photodiode 7. The output of the latter through an amplifier 8 is connected to a frequency meter 9 (it is also a pulse number meter).

 The level gauge works as follows.

 In the absence of leakage or outflow of liquid from the tank (not shown in the drawing), the liquid level in the pipe 1 does not change and the signal at the output of the frequency counter 9 will be zero. As soon as liquid flows into the tank, the liquid level in the pipe 1 will change, which will lead to a change in the hydrostatic pressure on the fiber spool 5 located at the bottom of the pipe 1. At the same time, the hydrostatic pressure on the coil 4 will remain constant at any fluid level.

 This will lead to the appearance of 7 interference pulses at the output of the photodiode, the number of which carries information about the amount of flowing out or flowing fluid, and the frequency - about the flow rate (leakage) of the fluid, i.e., the flow rate of the fluid.

 The number and frequency of pulses are measured after amplification of the photocurrent in amplifier 8 by a frequency meter 9. The number of turns in the coils 4, 5 is chosen so that the number of pulses and their frequency are sufficiently high.

 Since the signal is of a frequency-pulse nature, the level gauge is not affected by noise of an amplitude nature: radiation stability of LED 6, sensitivity of photodiode 7, etc.

 On the other hand, interferences of a phase nature, for example, the temperature of a liquid, will also not affect the readings of the device, since both coils 4, 5 are in the same liquid.

 The readings of the frequency counter 9 can be calibrated in units of liquid quantity and flow rate, thereby achieving the technical result set in the application.

Sources of information
1. Japan patent 59-38522, cl. G 01 F 23/10, 1984.

 2. US patent 4397183, CL. 73-293 (G 01 F 23/08), 1983 - prototype.

Claims (1)

 A fiber-optic fiber level gauge for monitoring fluid outflow or leakage, comprising a vertically oriented cylindrical pipe in communication with a controlled reservoir, and a float and two optical fibers located in a vertical pipe, optically matched with an LED and a photodiode connected via an amplifier to a recorder, characterized in that that the optical fibers are made in the form of fiber coils optically coupled to an interferometer, while the first fiber coil is located at the bottom of the pipe, and W paradise - at the lower end of the float, and the recorder is in the form of the frequency.

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