平均强度法对双能量伽马射线灰分计读数的影响

摘要

双能量伽马射线灰分计采用平均强度法引入的误差由厚度及灰分变化2个因素引起.在特定的、简化的变化模式下对这些偏移作解析近似，进而对2个因素引起的误差作了比较.结果表明，厚度变化的影响是主要的.因而，根据计数率水平确定采样时间能大大减小此误差.蒙特-卡罗法模拟的结果证实了这一论断.%For dual energy Gamma ray coal ash gauge, the error induced by inten sity averaging is consisted of two parts, the error caused by thickness change and by ash content change The magnitudes of the two errors are compared using app roximate analytical expressions under a simplified change pattern. Numerical cal culation shows that the error induced by thickness change is dominant. A system that regulates sampling time according to countrate level therefore can reduce this error significantly and its performance is verified by MonteCarlo simulati on.