The filter paper method is an economical, easily accessible, and simple-to-use method to measure total or matric suction over a wide suction range. Difficulty in handling the filter paper can result in inaccurate water content determination of the filter paper leading to poor estimation of the suction. This paper examines the feasibility of using electrical resistivity of the filter paper in the non-contact mode to determine equilibrium time and to infer the total suction. It was shown that for a specific set-up, electrical resistance (ER) can be used in place of electrical resistivity. Relationships between ER and water content of the filter paper and between ER and total suction were first established. Finally, a prototype set-up is used to demonstrate how it can be used to measure the total suction of soil specimens. It was demonstrated that ER of the filter paper can be used to provide a reasonable estimate of total suction greater than 100 kPa with an error between −18 and +10%. Better accuracy can be achieved if each filter paper is calibrated before use.

中文翻译：

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使用电阻率进行吸力测量的滤纸法

滤纸法是一种经济、易于访问且易于使用的方法，可在较宽的吸力范围内测量总吸力或基质吸力。处理滤纸的困难会导致滤纸的含水量测定不准确，从而导致对吸力的估计不佳。本文研究了在非接触模式下使用滤纸的电阻率来确定平衡时间和推断总吸力的可行性。结果表明，对于特定设置，可以使用电阻 (ER) 代替电阻率。首先建立了ER与滤纸含水量之间以及ER与总吸力之间的关系。最后，原型设置用于演示如何使用它来测量土壤样本的总吸力。经证明，滤纸的 ER 可用于提供大于 100 kPa 的总吸力的合理估计，误差介于 -18 和 +10% 之间。如果每张滤纸在使用前都经过校准，则可以获得更好的精度。