Behavior of capacitive humidity sensors in monitoring the drying of concrete walls

Tampere University, Building Physics, 33720 Tampere, Finland

^* Corresponding author: tuomas.raunima@tuni.fi

Abstract

This research examines the behavior of capacitive humidity sensors in monitoring the drying of concrete walls in continuous measurements in laboratory conditions. Tests are carried out using continuous measuring of moisture with different capacitive sensors in concrete structures varied with three different types of thermal insulation materials. Sensors are sealed in plastic tubes that were preinstalled into the casting molds. Three borehole measurements are carried out as reference during the research. Results show differences in performance between the examined humidity sensors from two different manufacturers. The main difference is related to stability as sensors from the other manufacturer prove to be more prone to error. The study affirms that measuring humidity in concrete is challenging even when using high-quality humidity sensors.