CVFI flashcards
CVFI · Build recall with a focused review session.
32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Fire tetrahedron
- Four components required for flaming combustion: fuel, oxidizer, heat, and uninhibited chemical chain reaction. Removing any one component extinguishes the fire.
- Flash point
- The lowest temperature at which a liquid fuel produces enough vapor to form an ignitable mixture with air near its surface, measured by closed-cup testing.
- Ignition temperature
- The minimum temperature at which a fuel vapor-air mixture self-heats and ignites without an external pilot source.
- Flammable range
- The concentration range of fuel vapor in air between the lower and upper flammable limits within which ignition can occur; gasoline is roughly 1.4 to 7.6 percent.
- Thermal runaway
- A self-accelerating exothermic reaction in lithium-ion cells where heat generation exceeds heat dissipation, causing cell venting, fire, and propagation to adjacent cells.
- Copper annealing
- A temperature indicator in fire investigation; copper wire softens and anneals above roughly 400 to 500 degrees Celsius, indicating exposure to high heat.
- Magnesium fire signature
- Magnesium alloys used in instrument panels and transmissions burn with a brilliant white flame and leave white oxide residue, helping identify high-temperature origin areas.
- Heat release rate
- The rate at which a fire releases energy, measured in kilowatts; it governs fire growth and time to flashover in a vehicle compartment.
- Origin determination
- The process of locating where a fire began by identifying the area of greatest damage, tracing to the lowest point of burning, and correlating with fuel and ignition sources.
- Arson indicators
- Evidence such as multiple separate origins, accelerant pour patterns, foreign timing devices, and removed valuables that suggests an intentionally set fire.
- Accidental fire indicators
- Evidence such as localized electrical arcing at a fault, fuel line failure near a heat source, and mechanical friction damage consistent with component failure.
- Fuel tank explosion
- Ignition of a fuel-air mixture in a vehicle tank vapor space, producing outward deformation of the tank and blast damage radiating outward.
- Deflagration
- A combustion wave that propagates below the speed of sound, producing a pressure wave without the supersonic shock of a detonation.
- Detonation
- A combustion wave that propagates supersonically, producing a shock wave and characteristic shattering and cratering of materials.
- Post-blast indicators
- Physical evidence after an explosion including pitting, cratering, metal fragmentation, and directional soot patterns used to locate the seat of the explosion.
- Chain of custody
- Documentation tracking physical evidence from recovery through laboratory analysis, recording each transfer, handler, and storage location.
- Accelerant detection
- Laboratory analysis, typically headspace GC-MS, used to confirm ignitable liquid residues; field odor and burn patterns are presumptive only.
- Scientific method in NFPA 921
- A six-step process: identify the problem, collect data, analyze data, develop a hypothesis, test the hypothesis, and select the final hypothesis.
- Cause classification
- Fire cause categories under NFPA 921: accidental, natural, incendiary, or undetermined; investigators must not default to accidental when evidence is insufficient.
- Area of origin
- The location where a fire began, determined from fire patterns, witness observations, and physical evidence, distinct from the cause.
- Fire cause
- The circumstances that brought an ignition source and fuel together to start a fire, determined after the area of origin is established.
- Negative corpus
- A prohibited practice of declaring a fire incendiary by eliminating all accidental causes without affirmative evidence of an incendiary cause.
- Pattern corroboration
- The NFPA 921 requirement that a single fire pattern not be used as sole proof of origin; patterns must be supported by multiple independent lines of evidence.
- Rekindle
- A subsequent fire caused by remaining heat sources after the initial fire was thought extinguished; investigators must distinguish it from the initial fire.
- Documentation requirements
- Photographs, diagrams, measurements, witness statements, and a written report explaining the reasoning and evidence supporting the investigator's conclusions.
- Report structure
- A fire investigation report typically includes summary, scene description, evidence collected, analysis, origin determination, cause determination, and conclusion.
- Opinion support
- The requirement that opinions in a report be supported by evidence, distinguishing observation and data from interpretation.
- Photographic labeling
- Photographs and diagrams must be labeled with date, time, location, and orientation to preserve evidentiary value.
- Hypothesis documentation
- The practice of documenting all hypotheses considered, including those rejected, and explaining why each was rejected.
- Explosion report content
- Documentation of blast damage, fragment distribution, and chemical residue analysis, including consideration of a possible fuel-air explosion.
- Objective language
- Report writing that avoids conclusory statements unsupported by evidence and remains clear, factual, and subject to peer and legal scrutiny.
- Peer review
- Independent review of the report and evidence by a qualified second investigator before finalization as part of quality assurance.