Traveling Sensor for Ceramic Fabric Cumulative Moisture Exposure, with Portable Dielectric Spectroscopy Instrument

The proposed program will develop dielectric spectroscopy methods for monitoring the cumulative moisture exposure and absorption for coated ceramic fabric during storage and handling. This will be accomplished with a traveling passive sensor stored with the fabric, implemented as an Interdigitated Electrode Dielectrometer (IDED) in contact with a palette of sensitive materials. This palette may include: material highly sensitive to cumulative moisture absorption, material that closely tracks the properties of the fiber coating, materials with unchanging properties used for reference and calibration, and possibly materials to measure relative humidity and exposure to other contaminants. The passive traveling sensor will be interrogated periodically with a low cost hand-held data logger via a direct cable connection or a wireless link. The IDED will also be capable of directly measuring the dielectric properties of the fabric itself, at one or more locations. The current industry practice of using humidity threshold sensors and manual logging are highly inadequate in determining ceramic fabric damage due to moisture exposure. This new tool will therefore be valuable in preventing the manufacture of composites with compromised mechanical properties and will eliminate the cost of unnecessarily discarding undamaged fabric that may have been briefly exposed to high humidity.