Gabriel C, Peyman A
MCL, 11 Kings Road West, Newbury, Berkshire, RG14 5BY, UK.
Phys Med Biol. 2006 Dec 7;51(23):6033-46. doi: 10.1088/0031-9155/51/23/006. Epub 2006 Oct 30.
The advantages and limitations of using partial differential analysis to assess the methodological uncertainty associated with the measurement of the dielectric properties of a material are discussed and an alternative pragmatic approach is proposed. It relies on repeat measurements of the dielectric properties of reference liquids and an analysis to estimate random and systematic uncertainties. Examples of measurement uncertainty are provided for well-defined monomolecular materials and for less homogeneous materials at microwave frequencies. All examples relate to measurement with an open-ended coaxial probe but the methodology is not specific to this technique. Examination of the components of uncertainty in the dielectric properties of biological tissue shows that, where the system is free of methodological bias, random fluctuations originating from sampling and natural inhomogeneity dominate the uncertainty budget. In such cases, the mean value of the measured parameter and the standard error of the mean can be taken as a good measure of the true value and its associated uncertainty.
讨论了使用偏微分分析来评估与材料介电性能测量相关的方法学不确定性的优点和局限性，并提出了一种实用的替代方法。该方法依赖于对参考液体介电性能的重复测量以及用于估计随机和系统不确定性的分析。给出了在微波频率下明确的单分子材料和不太均匀材料的测量不确定度示例。所有示例均涉及使用开放式同轴探头进行测量，但该方法并非特定于此技术。对生物组织介电性能不确定性成分的研究表明，在系统没有方法学偏差的情况下，采样和自然不均匀性引起的随机波动在不确定性预算中占主导地位。在这种情况下，测量参数的平均值和平均值的标准误差可作为真实值及其相关不确定性的良好度量。
