As a basis for the electrical tomography of laboratory-scale rock samples (~ 10 cm), we developed a procedure for stable, multi-point, electrical measurement on rock samples that is effective even at high contact and sample resistance. Electrodes were strongly attached to the surface of high-resistivity rock using conductive and adhesive epoxy. Sustained current injection for long periods into high-resistance rocks was fulfilled using a constant direct current source with high internal resistance. Accurate voltage measurement across the high-resistance rock was accomplished by differential measurement using two high input resistance voltmeters. Measurements of high resistance also require a stable measurement environment: the temperature and humidity in the laboratory were controlled using an air conditioner, a humidifier, a dehumidifier, and a vinyl tent. Signal noise arising from human activities was eliminated by the remote operation of the measuring equipment and switching terminal. The proposed measurement procedure was evaluated in terms of the stability and accuracy of measured values and its applicability to electrical tomography. To assess measurement stability, we performed multiple measurements of a dry granite sample at various levels of absolute humidity. Our procedure recorded highly reproducible measurements under each humidity condition. The observed changes in measured values with absolute humidity indicate the importance of stabilising the temperature and humidity conditions in the laboratory. Applying our technique to multiple plastic samples with known resistivity confirmed its accuracy. To evaluate its applicability to electrical tomography, we measured the potential distribution on a dry granite surface in response to an injected current using a simple 40-electrode array. The potential distribution measured by our procedure agreed well with that predicted by forward modelling, demonstrating the robustness of our procedure in array measurements, and thus indicating its potential applicability to tomographic measurements for a variety of targets even under severe conditions including the relative dryness of ambient humidity.

作为实验室规模岩石样品（~ 10 cm）电断层扫描的基础，我们开发了一种对岩石样品进行稳定、多点电测量的程序，即使在高接触电阻和样品电阻下也能有效。电极使用导电和粘性环氧树脂牢固地附着在高电阻率岩石的表面。使用具有高内阻的恒定直流电源实现了对高电阻岩石的长时间持续电流注入。通过使用两个高输入电阻电压表的差分测量来实现高电阻岩石上的准确电压测量。高阻测量还需要一个稳定的测量环境：实验室的温度和湿度是用空调、加湿器、除湿机、和一个乙烯基帐篷。通过远程操作测量设备和开关终端，消除了人为活动产生的信号噪声。根据测量值的稳定性和准确性及其在电断层扫描中的适用性对建议的测量程序进行了评估。为了评估测量稳定性，我们在不同绝对湿度水平下对干燥的花岗岩样品进行了多次测量。我们的程序在每种湿度条件下都记录了高度可重复的测量结果。观察到的测量值随绝对湿度的变化表明稳定实验室温度和湿度条件的重要性。将我们的技术应用于具有已知电阻率的多个塑料样品，证实了其准确性。为了评估其对电断层扫描的适用性，我们使用简单的 40 电极阵列测量了响应注入电流的干燥花岗岩表面的电位分布。我们的程序测量的电位分布与正向建模预测的分布非常吻合，证明了我们的程序在阵列测量中的稳健性，从而表明即使在包括环境相对干燥在内的恶劣条件下，其对各种目标的断层扫描测量的潜在适用性湿度。