传感技术学报
傳感技術學報
전감기술학보
Journal of Transduction Technology
2013年
12期
1627-1631
,共5页
赵耕砚%胡晓东%邹晶%赵金涛%陈津平
趙耕硯%鬍曉東%鄒晶%趙金濤%陳津平
조경연%호효동%추정%조금도%진진평
显微CT%光耦探测器%放大倍数标定%无损检测
顯微CT%光耦探測器%放大倍數標定%無損檢測
현미CT%광우탐측기%방대배수표정%무손검측
micro-CT%lens-coupled detector%magnification calibration%non-destructive testing
X射线显微CT因其较高的成像分辨率,被应用于微小样品内部精细结构的检测。分辨率是显微CT最受关注的指标之一,而实现其测量功能则是当今CT研究领域的前沿方向。为了提高分辨率,设计实现了一种基于光耦探测器的显微CT系统,对经过几何放大的图像再进行光学放大。由于对其放大倍数的准确标定是实现其测量功能的重要前提,研究提出了基于标准栅格板和标准球的标定方法,对基于光耦探测器的显微CT的光学放大倍数和几何放大倍数分别进行了标定。这样即使在实际测试中射线源、样品和探测器的位置发生改变,亦可直接算出总放大倍数。标定过程还使用了最小二乘法以提高标定精度。二维X射线投影图像测量实验和三维重建结果测量实验显示,此种放大倍数标定方法是准确、有效的。
X射線顯微CT因其較高的成像分辨率,被應用于微小樣品內部精細結構的檢測。分辨率是顯微CT最受關註的指標之一,而實現其測量功能則是噹今CT研究領域的前沿方嚮。為瞭提高分辨率,設計實現瞭一種基于光耦探測器的顯微CT繫統,對經過幾何放大的圖像再進行光學放大。由于對其放大倍數的準確標定是實現其測量功能的重要前提,研究提齣瞭基于標準柵格闆和標準毬的標定方法,對基于光耦探測器的顯微CT的光學放大倍數和幾何放大倍數分彆進行瞭標定。這樣即使在實際測試中射線源、樣品和探測器的位置髮生改變,亦可直接算齣總放大倍數。標定過程還使用瞭最小二乘法以提高標定精度。二維X射線投影圖像測量實驗和三維重建結果測量實驗顯示,此種放大倍數標定方法是準確、有效的。
X사선현미CT인기교고적성상분변솔,피응용우미소양품내부정세결구적검측。분변솔시현미CT최수관주적지표지일,이실현기측량공능칙시당금CT연구영역적전연방향。위료제고분변솔,설계실현료일충기우광우탐측기적현미CT계통,대경과궤하방대적도상재진행광학방대。유우대기방대배수적준학표정시실현기측량공능적중요전제,연구제출료기우표준책격판화표준구적표정방법,대기우광우탐측기적현미CT적광학방대배수화궤하방대배수분별진행료표정。저양즉사재실제측시중사선원、양품화탐측기적위치발생개변,역가직접산출총방대배수。표정과정환사용료최소이승법이제고표정정도。이유X사선투영도상측량실험화삼유중건결과측량실험현시,차충방대배수표정방법시준학、유효적。
X-ray computerized microtomography ( micro-CT ) is used to test tiny structures due to its high image resolution. Image resolution is one of its most important characteristics,and actualizing its measuring function is the cutting edge of CT research. To enhance its resolution,a micro-CT based on a lens-coupled detector was designed and actualized, which magnified samples optically besides geometric magnification. Since calibrating its magnification accurately is a premise to realize measurement with it,a calibration method using a grid pattern and a standard ball was proposed, which calibrated the optical magnification and the geometrical magnification respectively. Even if positions of the X-ray source,the sample and the detector are changed in later measurements, the total magnification can also be calculated. To increase calibrating precision,least square method was involved. Measurement experiments on 2 D projection images and a 3 D reconstruction result show that the calibration method is precise and valid.