在测量尺寸较小样本时，样本安装基底可能会成为测量误差的主要来源，这是其体积和表面电阻率造成的。通过（可能被污染的）基底表面阻止漏电流[1]的方法是，使用两个分开的绝缘片，而不是将样本放置在一个绝缘片上。为了简化对不同尺寸小型样本的测试，安装硬件应当包括测微螺旋，以调整两个绝缘片[2]之间的缝隙宽带。

When characterizing small samples, the substrate on which thesample is mounted can become a significant source of measure-ment error, as result of both its volume and surface resistivity.The obvious way to prevent any leakage current through a (pos-sibly contaminated) substrate surface is to use two insulator plates separated by a gap, rather than placing the sample on asingle plate. To simplify testing small samples of various sizes,the mounting hardware should include a micrometer screw toadjust the width of this gap.

 

图2: 使用液体镓（不会弄湿大多数材料）可以对同一晶体的不同方向进行测量。为了避免造成漏电流，样本要放置到两个蓝宝石片构成的间隙中。

 

Figure 2: Using liquid gallium, which doesn’t wet most materials, allows measuring conductivity in different directions on thesame crystal. To avoid creating leakage currents, the sample is placed on a gap formed by two sapphire plates.

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