Electrochemical Based Composite Moisture Sensor

Moisture present in composite laminations or honeycomb structures makes repair operations difficult and time consuming. If the moisture id not removed, high vapor pressure (steam) formed at elevated temperatures, can result in blown skins and more extensive damage than existed before the repair attempt. Moisture concentrations in the composite or adhesive can also cause significant degradation in mechanical properties, leading to further damage during repair. Traditional procedures call for extensive drying times to ensure moisture removal (<0.5%). In response to N97-033, DACCO SCI, INC., proposes a Phase I SBIR program to develop an electrochemical impedance spectroscopy (EIS)-based sensor to detect moisture in composite and adhesives. This sensor, which will be adapted from a corrosion sensor which readily detects moisture absorption by paint coatings, would be a small hand-held probe with a portable computer. It would be suitable for field use in a repair depot, operations maintenance base, or on board ship.