A device and method for calibrating the acoustic wave scattering area of ​​a Doppler current meter

Abstract

The invention relates to a calibration device and method for a sound wave scattering region of a Doppler current meter. The device comprises a standard plate (3), an upper damper (4), a lower damper (5), a first connecting rod (61), a second connecting rod (62) and a moving mechanism. The standard plate (3) is formed by connecting the round tubes to each other. One end of each of the round tubes is provided with a long cone (34), and the other end is provided with a short cone (31). The moving mechanism includes a first guide rail (71), a first linear stepping motor (72), a rotary stepping motor (73), a turntable (74), a second linear stepping motor (75) and a second guide rail (76). The first connecting rod (61) is a straight rod, the second connecting rod (62) includes an upper verticalrod (621), a horizontal rod (622) and a lower vertical rod (623), and the axis of the lower vertical rod (623) and the rotation axis of the rotary stepping motor (73) are in the same straight line. The effective acoustic scattering region of the Doppler current meter can be accurately calibrated.

Description

Technical field [0001] The invention relates to a calibration device and method, in particular to a calibration device and method for the sound scattering area of ​​a Doppler current meter, belonging to the field of acoustic measurement. Background technique [0002] The Doppler current meter uses the Doppler effect produced by sound waves in a moving medium to measure flow velocity. The traditional Doppler current meter uses a front-end transducer to emit sound waves. The sound waves are scattered by moving media such as water currents, small particles, and bubbles. The scattered sound waves are received by another transducer. The Doppler frequency deviation generated by the moving object , Calculate the water flow rate. In the past, the speed measurement accuracy of calibrated ocean current meters was mostly carried out in the waters outside the field. The Chinese marine industry standard HY / T102-2007 (Acoustic Doppler Velocity Profiler Detection Method) was used as the guidin...

AI Technical Summary

Problems solved by technology

However, when using Doppler ocean current timing, a transducer is required to emit sound waves and a transducer to receive sound waves. When the transducer is powered on, it will produce nonlinear effects. At this time, the reciprocity of sending and receiving is no longer satisfied. Therefore, , there are certain problems in calibrating the intersection area of ​​the transducer with the acoustic flow imaging method

[0007] In addition, there is a method of using a needle hydrophone to calibrate the effective acoustic scattering area of ​​the Doppler current meter. This method is limited by the sensitivity of the hydrophone. When a hydrophone with higher sensitivity is used to complete the calibration, It will make the effective acoustic scattering area too large; when the hydrophone with lower sensitivity is used to complete the calibration, the effective acoustic scattering area will be too small; moreover, the hydrophone has a certain volume and size, when the local structure feels the sound wave When the pulsating pressure is high, there will also be an electrical signal output, which is one of the reasons for the error in the calibration area

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