A robust heat flux sensor was developed in order to quantify the energy release from high heat load scenarios, such as wildland fires. In order to reduce the high errors in the heat flux data, the sensor was modified to measure the differential temperature so as to mitigate the propagation of error. Controlled laboratory and field validation tests were performed to verify the reduction in error and the results were compared to those obtained from an unmodified sensor and a commercial heat flux

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... ensor. The capabilities of the improved sensor design were further expanded by application of the sensor to the evaluation of wildfire chemicals. As a result, a simple and effective test methodology was developed for differentiating wildfire chemicals based on the ignition time of foliar vegetative fuel samples. The modified heat flux sensor was used to determine the time to flaming ignition along with the incident heat flux and the results obtained were compared to those obtained from the transient mass loss data measured by a strain gauge-based load cell. Statistical t-test analysis was conducted on the time-to-ignition data to determine whether the results were statistically significant for the different chemical treatments. The results indicated that the test methodology allowed for effective differentiation between the wildfire chemical treatments by comparing their mean ignition times. The narrow standard deviations of the mean ignition times suggested that the test methodology was able to produce repeatable results. Based on the custom heat flux sensor design and the developed methodology, a thermal calorimeter was then designed to measure the heat release rate of the foliar vegetative fuel samples, which is considered to be a useful thermal property. iii ACKNOWLEDGMENTS