How Long Does A Fire Investigation Take??
Hicks et al. (2006; 2008) conducted a reproducibility study on fire patterns using individual fuel elements. Forty-eight tests were performed with a standardized ANSI / UL wooden cradle and ten additional tests were performed with commercially available polyurethane foam. The fuels are burned against a plaster panel coating material in a compartment covered with drywall. Twelve thermocouples were mounted on a grid over the fuel element to record temperatures during the tests.
The interpretation of the causal factors for generating fire patterns was the following evaluation. Finally, the availability of processes using fire patterns to determine an area of origin was evaluated. This deconstruction of the problem provides a gap analysis of the current processes and identifies areas where future work is needed. A seven-step reasoning process is proposed to assess damage to determine the area of origin, along with a new definition of the term fire pattern. Fire and arson investigators investigate the physical characteristics of a fire scene and identify and collect physical evidence of the scene.
Data collection after the test included research, photography and a subset of character depth measurements. Preliminary results indicated that it is possible to generate comparable, but not identical, floor fire patterns between carpet seams and flammable liquid drains (Figs. 7, 8 and 9). However, Schroeder’s study was the first to quantify the depth of the calcination and its relationship within fire investigations. In this study, experimental samples of drywall wall plates were exposed to different heat flows for different periods of time using the Cono ASTM E1354 radiation heating. Schroeder was able to illustrate that a crystalline change would occur in the drywall when heated using an X-ray diffraction technique. His findings indicate that the drywall was the only material that could be used reliably to predict purposes.
Madrzykowski and Fleischmann conducted a study of the plasterboard response and reproducibility of the damage pattern caused by exposure to known heat output fires with different types of fuel sources and wall construction. The fuels used for his experiments included a natural gas burner, gasoline fire and polyurethane foam. The wall construction was varied between a single plate plasterboard with a wooden frame, a plasterboard on the front and back with a wooden frame and plasterboard on the front and back with fiberglass combat insulation in the holes of the wooden frame. This study focused on the effects where the paper was burned and where the paper was collected . To achieve this, the researchers evaluated the variability of flame height compared to height and damage area. As expected, the results indicated that the patterns generated by the polyurethane foam fire were more uncertain than the natural gas and gasoline fires.
Carman’s study did not produce the demographics of those present, nor did it provide statistical accuracy. Carman attributed the failure to the lack of understanding of the research profile of the differences between pre- and post-flight fire behavior and the resulting damage. Since then, the authors have noted several limitations of this exercise, including that participants should not complete a full compartment investigation, move items, and come to a conclusion Fire Expert Witness California based on their visual interpretation of the damage caused by the door . This test was conducted as part of a conference where conference participants had to evaluate fire scenes on their origins. It was reported that “many of the researchers struggled to find the location of the point of origin, which in many cases indicates the other side of the room.” . In 1992, the first edition of NFPA 921 identified most of these old indicators as misconceptions.