New Thermal Sensors for Use with Inverse Heat Conduction Problems

"Transient and high intensity heat transfer events are difficult to characterize by conventional means. Temperature is inherently an integral so precise information about the transfer process is lost by averaging. A temperature measurement can bedifferentiated, but then small errors due to noise and limited resolution are exaggerated. Moreover, high intensity transients can lead to temperatures that are destructively high for conventional sensors.To accurately characterize transients, an instrument is needed that can directly measure heat flux, or the rate of change of temperature dT/dt, over a broad temperature range. Jona proposes to address this need with a combination of calibratedintermediates with isolated elements, and dynamic range compression. Internal heat transfer will attenuate potentially destructive temperature peaks, while range compression enhances resolution and linearity.Objectives of Phase I are:1. Survey potential instrument applications and develop a classification to minimize the required variations.2. Develop conceptual designs for both heat flux and dT/dt measurements, and determine structural and dynamic requirements.3. Develop means to compensate for actual temperature when measuring dT/dt.4. Confirm critical mechanisms empirically and demonstrate direct rate measurement.5. Prepare a preliminary design for prototypes to be built in Phase II The proposed instrument will permit accurate measurement of rapid the