The technology of forensic examination of burned copper cord

Abstract

Technical forensics is a very broad scientific field. This paper reports one of its aspects, which refer to the testing of electrical conductors following a fire in order to identify the real cause of its appearance, namely providing information whether or not the electric cord damage caused the fire and to offer contribution to the authorities. For this purpose, sectional tests of copper electric cord were conducted using microstructure optical microscope as well as X-ray diffraction analysis. The sample preparation process has been also described. The interpretation of the obtained results with the adopted conclusions based on the above-mentioned tests was presented. Based on these analyses, it was concluded that there was a local melting of the conductors influenced by high temperatures achieved in oxygen atmosphere, and that melting was apparent within all samples.

Tehnička forenzika je jako široka naučna oblast. U ovom radu će se govoriti o jednom njenom segmentu koji se odnosi na ispitivanje električnih provodnika nakon požara, u cilju otkrivanja njegovog stvarnog uzroka, tj. prihvatanja ili odbacivanja kvara na elektoinstalacijama kao uzroka požara i pribavljanja informacija istražnim organima za rašavanje postavljenog zadatka. U tu svrhu su izvršena mikrostrukturna ispitivanja preseka bakarne žice korišćenjem optičkog mikroskopa i rendgenostrukturna analiza istih. Opisan je, takođe, i proces pripreme uzoraka kao i tumačenje dobijenih rezultata sa zaključcima donesenim na osnovu pomenutih rezultata ispitivanja. Na osnovu urađenih analiza je zaključeno da je došlo do lokalnog topljenja provodnika pod dejstvom visoke temperature u atmosferi kiseonika, a topljenje je uočeno kod svih ispitivanih uzoraka.