10.Examination_of_Erasures.ppt

Examination of Erasures

1. EXAMINATIONOFERASURES
Session-10

2. Erasure,removinginformationfromtheoriginal
document,canbeaccomplishedbyabrasiveor
chemicalmeans.Abrasiveerasure,thekindone
normallydoeswithapencileraser,disturbsthe
finishofthepapersurface.Dependingonthe
degreeofdamage,theevidenceoferasurecanbe
seenwiththeunaidedeyeoramicroscope.Some
samplesrequiresidelighting,placingalightsource
atanangletothesurfaceofthepaper,todetectan
erasure.

3. TYPESOFERASURES
1.ChemicalErasures:Differentkindofchemicals
presentnowadayswhichremoveallthecontentof
theinkwhereonecanwritewithsameflow.
2.PhysicalErasures:InthiscategoryBlades,Pins
orotherthingsareusedwhichremovethesurface
ofpaperandalsoherewefindthechangesinthe
inkdispersion.

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