Performance testing of wildland fire chemicals using a custom-built heat flux sensor

A simple and effective laboratory test methodology was developed for differentiating wildland fire chemicals based on the ignition time of vegetative fuel samples. The test apparatus consisted of an electric-powered radiant heater that was used to produce a uniform radiant thermal load to ignite the vegetative fuel samples. The samples, treated with wildland fire chemicals, were mounted on to a load cell to determine the transient mass loss during the combustion process. A custom-built heat flux sensor, that was modified and tested to reduce high errors, was used to determine the time to flaming ignition. The time to flaming ignition was also measured using transient mass loss data of the vegetative fuel samples. Statistical t-test analysis was conducted on the time to flaming ignition 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 wildland fire chemical treatments by comparing their mean ignition times. The narrow standard deviations of the average ignition times suggested that the test methodology was able to produce repeatable results.