Ultrasonic flowmeter compatible with both of pulse doppler method and propagation time difference method, method and program for automatically selecting the measurement method in the flowmeter, and el

A pulsed Doppler and measurement method technology, applied in the field of ultrasonic flowmeters, can solve the problems of limited flow rate measurable range and inability to measure fluids, and achieve high accuracy.
CN1922468AActive Publication Date: 2007-02-28FUJI ELECTRIC CO LTD
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
FUJI ELECTRIC CO LTD
Publication Date
2007-02-28

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Abstract

The reliability of a reception wave from a transducer is checked and when the reliability is determined to be insufficient, a method different from the current method is selected. The reliability is judged by calculating a value serving as an index of the reliability of the reception wave and checking whether the value is smaller than a predetermined set value. When the value is smaller than the set value, the reliability is judged to be insufficient. The values serving as an index of the reliability of the reception wave may be the amplitude of the reception wave, the ratio of the amplitude of the reception wave against a predetermined measurable amplitude value, the ratio of the power spectrum against a predetermined power value, the ratio of the transmission wave amplitude against the maximum amplitude of the reception wave, the ratio of the power spectrum of the transmission frequency included in the reception wave and obtained by Fourier transform of the reception wave against a predetermined power value, and the like.
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Description

technical field

[0001] The present invention relates to a technique of switching a measurement method between a pulse Doppler method and a transit time method using an ultrasonic flowmeter capable of measuring flow in both the pulse Doppler method and the transit time method. Background technique

[0002] The pulse Doppler method and the transit time method are known ultrasonic flow measurement methods.

[0003] Flow measurement in the pulsed Doppler method employs Doppler frequency shift, in which ultrasonic pulses are transmitted to the fluid to be measured, and the frequency of the ultrasonic echoes reflected by inclusions such as air bubbles present in the fluid is changed with A quantity proportional to flow rate. Compared with the through-time method, the pulse Doppler method is characterized by high accuracy, quick response, excellent anti-bubble characteristics, and high accuracy even in skewed flow by providing multi-level measurement lines . However, there are p...

Claims

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