Method for eliminating small flow zero drift

Abstract

The invention relates to a method for eliminating small flow zero drift. The ultrasonic flowmeter comprises a first ultrasonic transducer and a second ultrasonic transducer which are oppositely arranged on the wall face of the flow channel, the included angle between an ultrasonic sound channel between the first ultrasonic transducer and the second ultrasonic transducer and the axis of the flow channel is theta, and the second ultrasonic transducer is located on the downstream of the first ultrasonic transducer. Ta and Tb are obtained; calculation is performed; Tc and Td are obtained, and calculation is performed; when the ultrasonic flowmeter calculates the flow velocity V of the fluid in the flow channel, the zero drift time is eliminated by utilizing the time difference so as to accurately calculate the flow velocity V of the fluid in the flow channel, and then the flow in the flow channel is correspondingly calculated according to the V and the cross section area of the flow channel. According to the method for eliminating small flow zero drift, zero drift time data can be calculated, zero drift time is eliminated, accurate calculation of the flow velocity and the flow in the flow channel is achieved, and the calculated data is more accurate.

Description

technical field [0001] The invention relates to a method for eliminating zero drift of small flow. Background technique [0002] Ultrasonic flowmeters are widely used in pipelines to measure gas, water and other fluids. For example, ultrasonic gas flowmeters are mostly used in industrial fields with large flows, and in commercial fields with larger users and smaller gas consumption. [0003] Ultrasonic flowmeters usually use the time difference method to measure the flow velocity of the fluid. Due to the problem of zero drift in the internal circuit, the propagation time of the ultrasonic wave in the sound channel contains a delay when used, thus affecting the flow velocity measurement of the fluid, which in turn leads to its measurement accuracy. decline. In the prior art, the time delay can only be measured when the fluid flow rate is 0, but in practical applications, the condition of the fluid flow rate being 0 cannot be met, and thus cannot be applied to an actual ultra...

AI Technical Summary

Problems solved by technology

[0003] Ultrasonic flowmeters usually use the time difference method to measure the flow velocity of the fluid. Due to the problem of zero drift in the internal circuit, the propagation time of the ultrasonic wave in the sound channel contains a delay when used, thus affecting the flow velocity measurement of the fluid, which in turn leads to its measurement accuracy. decline

In the prior art, the delay can only be measured when the fluid flow rate is 0, but in practical applications, the condition of the fluid flow rate being 0 cannot be met, and thus cannot be applied to the actual ultrasonic flowmeter

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