Ultrasonic flower meter for eliminating zero point error

Abstract

The invention discloses an ultrasonic flower meter for eliminating zero point error, which comprises an outer tube, wherein an ultrasonic transmitting probe and an ultrasonic receiving probe are arranged in the outer tube; an ultrasonic column is arranged in the outer tube; the ultrasonic transmitting probe and the ultrasonic receiving probe are positioned at the positions of two ends of the ultrasonic column respectively; the ultrasonic transmitting probe and the ultrasonic receiving probe are arranged in the outer tube by adopting a strutting piece respectively; and the ultrasonic column is connected with the outer tube through the strutting piece. The ultrasonic flower meter can overcome the defects of the prior art, eliminate zero point error and fulfill the purpose of accurate measurement.

Description

technical field [0001] The invention relates to a flow meter, which is an ultrasonic flow meter capable of eliminating zero point errors. Background technique [0002] Ultrasonic flowmeters are widely used due to their advantages of accurate measurement and unimpeded operation compared with flowmeters with mechanical structures. However, the main structure of the transit-time ultrasonic flowmeters currently on the market is to install two ultrasonic probes upstream and downstream of the fluid, namely: the upstream probe and the downstream probe, the distance between the probes is fixed, and the ultrasonic probe is duplex. Yes, it can be used to transmit ultrasonic waves or receive ultrasonic waves. When there is fluid flow, there is a linear superposition relationship between the propagation speed of ultrasonic waves between the two probes and the flow velocity of the fluid. When the ultrasonic waves propagate smoothly, the speed must be added to the speed of the fluid. When...

AI Technical Summary

Problems solved by technology

The disadvantage of the ultrasonic flowmeter with this structure is: the measured time difference is composed of two parts, the first is the ultrasonic propagation time difference caused by the fluid flow, this time difference is the real time difference; the second is the probe and the circuit asymmetric delay caused by The time difference, this time difference is the error time difference

These two time differences are superimposed and cannot be distinguished, so the ultrasonic flowmeter has a large zero point error

In practical applications, since the ultrasonic probe cannot achieve consistent characteristics in manufacturing, the zero point error will change with factors such as temperature and pressure, resulting in zero point error drift. This zero point error drift makes the flowmeter have a large measurement error. When When measuring small flows, it often leads to measurement failures; in order to obtain ultrasonic flowmeters with small zero-point drift, manufacturers often adopt solutions such as strict matching of ultrasonic probes and symmetrical circuits. However, after a period of use, the aging of the probes will still cause The flow meter produces zero error and drift problems, which distort the measurement

For this reason, those skilled in the art have been continuously providing design solutions for many years, but none of them can eliminate the zero point error

Images