【摘要】 水的质量吸收系数μ在γ透射法测定土壤含水量中起着重要的作用,它直接影响着含水量的测量精度。本文通过室内试验研究了影响μ值的各种因素,如探头屏蔽状况、探头与放射源间的距离,放射强度以及被探测物体的厚度等。和理论计算不同,对同一确定的材料,μ值的测量结果并不总是常数(依赖于上述诸因素)。所以要得到土壤含水量的一个精确测量,首先要在同样条件下测定μ值。作为对试验的总结,本文给出一种合理测量μ值的方法和最佳工作条件。更多还原

【Abstract】 The mass absorption coefficient of water μ plays an important role in measuring soil moisture using v-radiation method. It can directly affect the measuring accurancy of soil moisture content.Bascd on the lab experiments, this paper studies various factors affecting n value including the probe shield, the distance between probe and radiation source, the radiant intensity and the thickness of radiated objects, etc. This is different from the theoretical calculation of n value , which is always a constant for any fixed material (i.c.indcpcndent of working conditions).Thcrcfore, in order to get an accurate measurement of soil moisture, μ value must be measured under the same condition. To sum up the experiments, a rational method and the best working conditions for measuring μvalue are given in this paper.更多还原