Long-term moisture content monitoring of nail-laminated timber bridge deck using Electrical Resistance (ER) method

A commercially available system made by Scanntronik Mugrauer GmbH (Germany) was used for this study. The on-site monitoring system consists two independent parts: a battery powered moisture meter with eight channels, namely Material Moisture Gigamodule, and a battery powered temperature sensor with two external channels to measure temperature and one internal temperature sensor for air temperature, namely Thermofox Universal. The pins that connected to the moisture meter are Teflon-insulated electrodes made by GANN (Germany) with two lengths, 15mm and 25mm, which enable the measurement of moisture content at specific depths. The system recorded the MC through Electrical Resistance (ER) method. The calibration test was conducted to correlate ER values recorded in Ohm with MC in percentage.