METHOD FOR PRELIMINARY PROCESSING OF ANALOGUE SIGNALS FROM SENSORS OF CLAMP-ON ACOUSTIC FLOW METER AND DEVICE FOR ITS IMPLEMENTATION Russian patent published in 2024 - IPC G01F1/00 

FIELD: measurement.

SUBSTANCE: group of inventions relates to means of processing signals in the field of measuring volumetric flow rate of liquid and gaseous media and can be widely used in measuring equipment in the oil and gas industry. Method for preliminary processing of signals consists in the fact that each of the analogue signals taken from the outputs of piezofilm sensors of the clamp-on acoustic flow meter and representing a bipolar alternating signal is first amplified. First, the constant component of the signal is filtered, then two-channel amplification and preliminary filtering of low frequencies are provided. Obtained signal is then transmitted to filtering out high-frequency noise and then amplifying the signal cleaned from high-frequency noise. Further, the obtained cleaned and amplified low-frequency signal is subjected to analogue-to-digital conversion and transmitted for further processing. This processing includes use of galvanic isolation for separation of measuring part from communication and power lines, and elimination of electromagnetic interference. Obtained signal is modulated by a HART protocol and the frequency-modulated digital data is transmitted over 4–20 mA current signal for subsequent processing or indication. In the device, each of piezofilm sensors 1 of the clamp-on acoustic flow meter is connected to its pre-processing unit (PPU) 2, each of which comprises series-connected analogue-to-digital conversion (ADC) board 3, consisting of series-connected bipolar signal preamplifier 4 with low-frequency signal filtering elements, filter-amplifier 5 and analogue-to-digital converter 6, as well as placed on microprocessor board 7 unit 8 of galvanic isolation, interface 9, microcontroller 10, 4–20 mA current loop generator 11 with HART protocol modulator and user indicator 12, and also separate k-ƒ module 13.

EFFECT: high quality of processing analogue signals from sensors of a clamp-on acoustic flow meter.

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