fire technology and arson investigation Flashcards
4 General Categories Of Heat Energy
Chemical Heat Energy
Electrical Heat Energy
Mechanical Heat Energy
Nuclear Heat Energy
a phenomenon in which a fire that has consumed all available oxygen suddenly explodes when more oxygen is made available, typically because a door or window has been opened.
Backdraft
The temperature of a substance where the rate of
evaporation exceeds the rate of condensation.
boiling point
(BTU) The amount of heat needed to raise the
temperature of one pound of water one degree F.
british thermal unit
The amount of heat needed to raise the temperature of one
gram of water one degree Centigrade.
calorie
(Celcius) On the Centigrade scale, zero is the melting
point of ice; 100 degrees is the boiling point of water.
centigrade
The amount of heat generated by the combustion (oxidation) process.
heat of combustion
The release of heat from decomposing compounds. These compounds may be unstable and release their heat very quickly or they may detonate.
heat decomposition
The heat released by the mixture of matter in a liquid. Some acids, when dissolved, give off sufficient heat to pose exposure problems to nearby combustibles.
heat of solution
The heating of an organic substance without the addition of external heat.
spontaneous heating
occurs most frequently where sufficient air is not present to dissipate the heat produced. The speed of a heating reaction doubles with each 180 F (80 C) temperature increase.
Spontaneous Heating
Classification of Fires
Class A Fire - Fires involving ordinary combustible materials, such as wood, cloth, paper, rubber and many plastics.
Class B Fires - Fires involving flammable liquids, greases and gases.
Class C Fires - Fires involving energized electrical equipment.
Class D Fires - Fires involving combustible metals, such as magnesium, titanium, zirconium, sodium and potassium.
Class K Fires - Class K is a new classification of fire as of 1998 and involves fires in combustible cooking fuels such as vegetable or animal fats.
the self-sustaining process of rapid oxidation of a
fuel being reduced by an oxidizing agent along with the evolution of heat and light.
combustion
method of fire extinguishment, interrupt the flame producing chemical reaction, resulting in rapid extinguishment.
dry chemicals and halons
The heating that results from the action of either pulsating direct current, or alternating current at high frequency on a non-conductive material.
dialectric heating
Heat released either as a high-temperature arc or as molten material from the conductor.
heat from arcing
The heat generated by the discharged of thousands of volts from either earth to cloud, cloud to cloud or from cloud to ground.
heat generated by lightning
The heating of materials resulting from an alternating current flow causing a magnetic field influence.
induction heating
The heat resulting from imperfect or improperly insulated electrical materials. This is particularly evident where the insulation is required to handle high voltage or loads near maximum capacity.
Leakage Current Heating
The heat generated by passing an electrical force through a conductor such as a wire or an appliance.
resistance heating
Heat released as an arc between oppositely charged surfaces. Static electricity can be generated by the contact and separation of charged surfaces or by fluids flowing through pipes.
static electricity heating
A chemical reaction where a substance
absorbs heat energy.
endothermic heat reaction
A chemical reaction where a substance
gives off heat energy.
exothermic heat reaction
On the Fahrenheit scale, 32 degrees is the melting point
of ice; 212 degrees is the boiling point of water.
Fahrenheit