探頭施力影響蘿蔔超音波特性之研究

Effects of Sensor Contact Force on the Ultrasonic Characteristics of Radish

黃威仁(Wei-Jen Huang) ； 盧福明(Fu-Ming Lu)

《農業機械學刊》 14卷4期 (2005/12) Pp. 13-24

https://doi.org/10.30062/JAM.200512.0002

摘要

本研究目的為結合萬能試驗機與超音波儀器，應用超音波探頭在不同施力狀況下擷取超音波穿透蘿蔔所得到的波形來分析探頭接觸測試物的施力影響超音波性質的程度。超音波穿透蘿蔔之衰減係數與施力之關係呈現衰減現象，能量頻譜與施力之關係呈現遞增現象。探頭施力會影響衰減係數與蘿蔔物性的相關係數。衰減係數(y)與施力(x)的迴歸式y=a+bLnx之係數a和蘿蔔孔隙率之關係較為顯著，係數b則與蘿蔔體積有關。而能量頻譜(y)與施力(x)的迴歸式係數a與蘿蔔孔隙率之關係較為顯著。

關鍵字

蘿蔔 ； 探頭施力 ； 超音波 ； 衰減係數 ； 能量頻譜

並列摘要

The objective of this study was to study the effect of contact force of ultrasonic probe on the ultrasonic attenuation and power spectrum of radish. The relationship between attenuation(y: neper/m) and contact force(x: kgw) can be expressed as y=a+bLnx, and the regression coefficients a and b were influenced by porosity and volume respectively. The relationship between power spectrum and contact force also has the same regression form, the coefficient a was influenced by porosity. The attenuation and power spectrum respectively decreased and increased with the increase of contact force. The correlation coefficient between physical properties of radish and attenuation was influenced by contact force.

並列關鍵字

Radish ； Contact force ； Ultrasonic ； Attenuation ； Power spectrum