Melt Globule
Definition
A rounded metal deposit formed when a conductor is heated to melting by ambient fire heat rather than by arcing; physically similar to an arc bead but shows a different solidification microstructure under SEM/EDS examination.
Related terms
- Annealing
- The heat-induced reorganisation of the crystal structure of steel at temperatures above approximately 720°C, resulting in reduced hardness and tensile strength; measurable...
- Arc Bead
- A small, rounded, resolidified deposit of copper or aluminium formed when an electrical arc melts the conductor and the material rapidly re-solidifies;...
- ASTM E1618
- Standard Test Method for Ignitable Liquid Residues in Extracts from Fire Debris Samples by Gas Chromatography-Mass Spectrometry. The active analytical standard defining...
- Calcination
- Bone transformation at temperatures above 700°C: complete combustion of the organic collagen fraction, leaving only white hydroxyapatite mineral. Destroys DNA, collagen (precluding...
- Char-Depth Probe
- A calibrated steel probe inserted perpendicular to a charred wood surface to measure the depth of charring; used systematically across a scene...
- Inverted-Cone Pattern
- A fire pattern with the apex at ceiling level and widening toward the floor, associated with fast-developing fires, flashover conditions, or ceiling-level...
- Negative Corpus
- The discredited practice of concluding incendiary fire cause by eliminating all identifiable accidental causes without positive physical evidence of intentional fire-setting. NFPA...
- U-Pattern
- A rounded variant of the V-pattern, associated with lower heat release rates and slower fire development; the broader base and higher apex...
- V-Pattern
- A V-shaped area of heat and smoke damage on a vertical surface, produced by the upward cone of the fire plume; the...
Explained in
- Origin and Cause: V-Patterns, Char Depth, Electrical IndicatorsA rounded metal deposit formed when a conductor is heated to melting by ambient fire heat rather than by arcing; physically similar to an arc bead but shows a...