Development and Validation of a Four-Electrode System for Impedance-Based Moisture Measurement in Concrete and Mortar

The accurate monitoring of moisture content in concrete and mortar is critical for guaranteeing proper curing, drying, and long-term performance of building materials. This work describes the design and validation of a four-electrode device for impedance-based moisture monitoring. The electrodes, made of stainless steel for durability and corrosion resistance, were tuned in size and spacing to enable effective ionic interaction and consistent electrical readings. A low-frequency sinusoidal voltage signal of 10V (1–10 kHz) was delivered to the input electrodes, while the output electrodes assessed the resultant potential difference and related it to moisture content. The system was tested in regulated temperature and humidity settings, with measurements taken at predetermined intervals. The results showed a substantial link between moisture content and electrical impedance/conductivity, indicating that impedance rises.