921 Definitions Flashcards
A rapid oxidation process, which is an exothermic chemical reaction, resulting in the evolution of light and heat in varying intensities
Fire
A flow of electric charge
Current.
the tendency of a material to move or deform permanently to relieve stresses.
Creep
Heat transfer to another body or within a body by direct contact
Conduction
An ignition source that has sufficient energy and is capable of transferring that energy to the fuel long enough to raise the fuel to its ignition temperature.
Competent Ignition Source
The heat, gases, volatilized liquids and solids, particulate matter, and ash generated by combustion
Combustion Products
A chemical process of oxidation that occurs at a rate fast enough to produce heat and usually light in the form of either a glow or flame
Combustion
a liquid that has a closed-cup flash point at or above 37.8°C (100°F).
Combustible Liquid
An instrument that samples air and indicates whether there are ignitible vapors or gases present
Combustible Gas Indicator.
Capable of undergoing combustion
Combustible
A distinct and visible fire effect generally apparent on noncombustible surfaces after combustible layer(s) (such as soot, paint, and paper) have been burned away
Clean Burn
Convex segments of carbonized material separated by cracks or crevasses that form on the surface of char, forming on materials such as wood as the result of pyrolysis or burning
Char Blisters
Carbonaceous material that has been burned or pyrolyzed and has a blackened appearance
Char
A relatively thin layer of flowing hot gases that develops under a horizontal surface as a result of plume impingement and the flowing gas being forced to move horizontally
Ceiling Jet
The circumstances, conditions, or agencies that brought about or resulted in the fire or explosion incident, damage to property, bodily injury, or loss of life.
Cause
The amount of heat necessary to raise 1 gram of water 1°C at the pressure of 1 atmosphere and temperature of 15°C
Calorie
A fire effect realized in gypsum products, including wallboard, as a result of exposure to heat that drives off free and chemically bound water
Calcination of Gypsum
The quantity of heat required to raise the temperature of one pound of water 1°F at the pressure of 1 atmosphere and temperature of 60°F
British Thermal Unit (Btu)
The permanent joining of metallic parts to form an electrically conductive path that ensures electrical continuity and the capacity to conduct safely any current likely to be imposed
Bonding
Boiling liquid expanding vapor explosion
BLEVE
The expanding leading edge of an explosion reaction that separates a major difference in pressure between normal ambient pressure ahead of the front and potentially damaging high pressure at and behind the front
Blast Pressure Front
A rounded mass of resolidified metal on the end of the remains of an electrical conductor or conductors that was caused by arcing and is characterized by a sharp line of demarcation between the melted and unmelted conductor surfaces
Bead
A deflagration resulting from the sudden introduction of air into a confined space containing oxygen-deficient products of incomplete combustion
Backdraft.
The lowest temperature at which a combustible material ignites in air without a spark or flame
Autoignition Temperature
Initiation of combustion by heat but without a spark or flame
Autoignition
the crime of maliciously and intentionally, or recklessly, starting a fire or causing an explosion
Arson.
A fire pattern displayed on the cross-section of a burned wooden structural member.
Arrow Pattern
A structure, part of a structure, or general geographic location within a fire scene, in which the “point of origin” of a fire or explosion is reasonably believed to be located.
Area of Origin
Arcing associated with a matrix of charred material (e.g., charred conductor insulation) that acts as a semiconductive medium
Arcing Through Char
The location on a conductor with localized damage that resulted from an electrical arc
Arc Site.
Melting of conductors and conducting surfaces as a result of electrical arcing. see 9.11.1.1
Arc Melting
Identifying and documenting a fire pattern derived from the identification of arc sites used to aid in determining the area of fire origin or spread.
Arc Mapping.
A high-temperature luminous electric discharge across a gap or through a medium such as charred insulation.
Arc.
The unit of electric current that is equivalent to a flow of one coulomb per second; one coulomb is defined as 6.24 × 1018 electrons.
Ampere.
The maximum current, in amperes, that a conductor can carry continuously under the conditions of use without exceeding its temperature rating. [70, Article 100]
Ampacity.
Someone’s or something’s surroundings, especially as they pertain to the local environment; for example, air and/or temperature.
Ambient
A system that uses moving mechanical or electrical parts to achieve a fire protection goal.
Active Fire Protection System
An unplanned event that interrupts an activity and sometimes causes injury or damage or a chance occurrence arising from unknown causes; an unexpected happening due to carelessness, ignorance, and the like.
Accident
A fuel or oxidizer, often an ignitible liquid, intentionally used to initiate a fire or increase the rate of growth or spread of fire.
Accelerant
A temperature (scale) measured in Kelvins (K) or Rankines (R)
Absolute Temperature.
Standard, code, recommended practice, or guide?
the main text of which contains only mandatory provisions using the word “shall” to indicate requirements and that is in a form generally suitable for mandatory reference by another standard or code or for adoption into law.
Standard.
A document that is similar in content and structure to a code or standard but that contains only nonmandatory provisions using the word “should” to indicate recommendations in the body of the text.
Recommended Practice.
A document that is advisory or informative in nature and that contains only nonmandatory provisions, but the document as a whole is not suitable for adoption into law.
Guide
A standard that is an extensive compilation of provisions covering broad subject matter or that is suitable for adoption into law independently of other codes and standards.
Code
The process of systematically utilizing logical techniques to dissect, reorder, evaluate, and interpret data.
Data Analysis
The process by which conclusions are drawn by logical inference from given premises
Deductive Reasoning
Propagation of a combustion zone at a velocity that is less than the speed of sound in the unreacted medium
Deflagration
The mass of a substance per unit volume, usually specified at standard temperature and pressure.
Density
1) Sensing the existence of a fire, especially by a detector from one or more products of the fire, such as smoke, heat, infrared radiation, and the like. (2) The act or process of discovering and locating a fire
Detection
Propagation of a combustion zone at a velocity greater than the speed of sound in the unreacted medium
Detonation
A gas, vapor, dust, particulate, aerosol, mist, fog, or hybrid mixture of these, suspended in the atmosphere, which is capable of being ignited and propagating a flame front
Diffuse Fuel
A flame in which fuel and air mix or diffuse together at the region of combustion
Diffusion Flame
The spread of fire by the dropping or falling of burning materials. Synonymous with “fall down.”
Drop Down.
Temperatures reached in fires that produce physical effects that can be related to specific temperature ranges
Effective Fire Temperatures
A small, incandescent particle created by some arcs.
Electric Spark.
A broad concept that includes public or private information stored in an electronic or digital medium,
Electronically Stored Information (ESI).
Factual data that is based on actual measurement, observation or direct sensory experience rather than on theory.
Empirical Data.
A property of matter manifested as an ability to perform work, either by moving an object against a force or by transferring heat.
Energy
The process of air or gases being drawn into a fire, plume, or jet.
Entrainment.
The sudden conversion of potential energy (chemical or mechanical) into kinetic energy with the production and release of gases under pressure, or the release of gas under pressure.
Explosion
Study of how chemistry, physics, fire science, engineering disciplines of fluid and solid mechanics, and heat transfer interact to influence explosion behavior
Explosion Dynamics.
Any chemical compound, mixture, or device that functions by explosion.
Explosive
Any material that can act as fuel for an explosion.
Explosive Material.
The side of a structural assembly or object that is directly exposed to the fire.
Exposed Surface.