Reducing Sensing Volume Confounding Effects in Conductivity Measurements: The Use of a Miniaturised Four-Electrode Probe

For conductivity measurements, the sensing volume is determined by the electrode size and geometry and can significantly confound results, particularly in smaller samples. In this study, we investigate the influence of the sensing volume on conductivity measurements. Two distinct four-electrode probes are used to measure the conductance of a 0.1 mol/l NaCl solution across various sample sizes. The miniaturised probe, despite its fragility, demonstrated consistent conductivity measurements across smaller sample sizes. Thus, validating the potential of the miniaturised probe for accurately assessing the conductivity of small, heterogeneous biological tissues. The findings from this study highlight the significance of considering sensing volume in conductivity measurements and showcases the advantages of using a miniaturised four-electrode probe, especially for small sample analysis.