SU1434262A1 - Device for measuring flow rate - Google Patents

Abstract

The invention relates to a technique for measuring the flow of liquids and can be used to measure low flow rates. The purpose of the invention is to improve the accuracy and ensure the reversible mode of operation, which is achieved by reducing the attenuation of the mark and the independence of the time of change of the signal from the direction of flow of the fluid. The device contains polarizer magnets 1, modulation coils 2 connected to generator 3 output modulation, signal registration coil 4 connected to the detector / dis rom 5, pole pieces 6, analyzer magnets 7 connected to the input voltage of the synchronous detector 8 and one of the inputs of the auto-search device 9, the signal input of the synchronous detector 8 and the second input of the auto-search device 9 are connected to the input of the detector 5. The code of the auto-search device 9 is connected to the frequency control input eneratsii detector 5. The output of the pulse generator 10 is coupled to the input audio utfavle- generating amplitude detector 5. The synchronous detector 8 and outputs the pulse generator 10 connected to processing unit 11 inputs. The flow information is input to the display device 12. Improving the accuracy and ensuring the reverse mode of operation is achieved by reducing the attenuation of the mark within one coil and the independence of the time of change of the mark signal from the direction of movement of the fluid. bones. 2 Il. about (L 4 O9 NSd GO CD ё

Description

The invention relates to a technique for measuring the flow of liquids by nuclear magnetic resonance (NMR) and can be used to measure low flow rates.

The purpose of the invention is to improve the accuracy and ensure the reversible mode of operation.

Fig. 1 shows a block diagram of a device for measuring flow; Fig. 2 shows timing diagrams characterizing the operation of the device: a) time dependence of the output voltage of the pulse generator; b) the time dependence of the amplitude of the resonant radiofrequency field generated by the detection coil; c) time dependence of the voltage at the output of the synchronous detector.

A device for measuring the flow contains polarizer magnets 1, modulation coils 2 connected to the generator 3 output, modulation coil 4 connected to the detector 5, pole pieces 6 and analyzer magnets 7 Modulation generator 3 outputs are connected to the reference input the voltage of the synchronous detector 8 and one of the inputs of the auto-search device 9, the signal input of the synchronous detector 8 and the second input of the auto-search device 9 are connected to the output of the detector 5, the output of the autonomy device 9 /: generation of the detector 5; the output of the pulse generator 10 is with the control input of the amplitude of generation of the detector 5, the outputs of the synchronous detector 8 and the generator of the 10 pulses are with the inputs of the processing device 11. Information about the flow enters the input device 12 of the display.

A device for measuring flow is as follows.

Liquid polarization is carried out in the field created by polarizer magnets 1. The NMR signal is observed periodically, for which the modulating sinusoidal audio frequency field created by the modulation coils 2 fed from the modulation generator 3 is used. The analysis of the magnetization vector of the double liquid is performed using a registration coil 4 connected

with the detector 5, during the absence of a pulse at the output of the generator 10. The mark of the liquid is produced by inverting the nuclear magnetization vector by the radio frequency field of the registration coil 4 with the arrival at the control input of the amplitude of the generation of the detector 5 of the pulse generated

0 by the generator 10. An automatic search for resonant conditions is carried out by changing the generation frequency of the detector 5 using the auto-searching device 9. The magnitude of the magnetization of the fluid is recorded at the second harmonic of the modulation frequency using a synchronous detector 8. The pulse is formed, the duration of which is inversely proportional to the flow rate, and the duration is converted into the flow rate by the processing device 11. The display device 12 displays information about the flow rate.

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The increase in the accuracy of the flow measurement occurs due to the decrease in the attenuation of the mark, and the provision of the reversible mode of operation is due to the fact that the signal change time does not depend on the direction of flow of the fluid.

Claims (1)

Invention Formula 5 A flow measurement device j based on nuclear magnetic resonance detection, comprising a pipeline, polarizer magnets and an analyzer, a modulation coil, connected to a modulation generator, a registration coil connected to a spin detector, which is connected to a time interval measuring unit , and display device, In order to improve accuracy and ensure reversing operation, the device includes a pulse generator and a synchronous detector, with a pulse generator connected between the spin detector and the time interval measuring unit, the inputs of the synchronous detector are connected to a generator connected to the coil module spin detector, and its output is connected to a time interval measurement unit. 0 five FIG. g