Dynamic measurement method for ultrasonic wave measuring instrument

Abstract

The invention relates to the technical field of ultrasonic wave flow measurement, in particular to a dynamic measurement method for an ultrasonic wave measuring instrument. The dynamic measurement method comprises steps as follows: (A), a sampling time difference deltat i is obtained after the ith time of circuit sampling is finished; (B), a sampling coefficient lambda i corresponding to the ith time is obtained according to the sampling time difference deltat i and following equations; (C), the condition of sudden change of flow is judged according to the (i-1)th sampling coefficient lambda (i-1) and the ith sampling coefficient lambda i, if jumping change happens, the sampling frequency is adjusted and a step E is started, and otherwise, a step D is started; (D), a sampling time difference filtering average value deltat (average) is obtained through averaging, deviation percentage f of the ith sampling is calculated, and the frequency is adjusted according to the f; (E),the volume Vi of the ith sampling is obtained through calculation. The next sampling frequency is adjusted continuously during flow measuring, and the system measurement precision is guaranteed; meanwhile, the sampling frequency is adjusted constantly, so that the energy consumption of the system is in a reasonable range, and compared with continuous high-frequency sampling, system power consumption is greatly reduced.

Description

technical field [0001] The invention relates to the technical field of ultrasonic flow detection, in particular to a dynamic measurement method for an ultrasonic measuring instrument. Background technique [0002] Ultrasonic meter is a kind of meter that adopts all-electronic principle for fluid flow detection. The accuracy of flow measurement is related to the signal sampling time interval, that is, the sampling frequency (or sampling period). The shorter the time interval between two adjacent signal sampling, The more sensitive the instrument is to the change of fluid flow, the higher the measurement accuracy is correspondingly under the condition of sudden flow change or continuous fluctuation; however, too high sampling frequency will increase the power consumption of the instrument, especially for flow meters powered by batteries , it is even more necessary to seek a balance between measurement accuracy and power consumption. At present, battery-powered ultrasonic meas...

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Problems solved by technology

[0002] Ultrasonic measuring instrument is a kind of instrument that adopts all-electronic principle to detect fluid flow. The accuracy of flow measurement is related to the signal sampling time interval, that is, the sampling frequency (or sampling period). The shorter the time interval between two adjacent signal sampling, The more sensitive the instrument is to the change of fluid flow, the higher the measurement accuracy is correspondingly under the condition of sudden flow change or continuous fluctuation; however, too high sampling frequency will increase the power consumption of the instrument, especially for flow meters powered by batteries , it is more necessary to seek a balance between measurement accuracy and power consumption

At present, battery-powered ultrasonic measuring instruments mostly adopt the method of fixed sampling frequency. Through experiments, a small fixed sampling frequency that meets the requirements of measurement accuracy is determined, so that the power consumption of the instrument can be reduced to a relatively low value. This method can make the instrument work in High measurement accuracy is achieved under standard working conditions or experimental conditions, and then under actual working conditions, the cumulative operating error will gradually increase

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