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What is infrared luminescence used for in forensic documents?

What is infrared luminescence used for in forensic documents?

It can also be used to possibly detect differences between to inks that look the same to the eye but fluoresce differently in the infrared. Sometimes a reflected infrared approach is sufficient to detect differences but the luminescence technique possibly yields additional corroborating information.

What is luminescence light?

luminescence, emission of light by certain materials when they are relatively cool. It is in contrast to light emitted from incandescent bodies, such as burning wood or coal, molten iron, and wire heated by an electric current.

What is the difference between fluorescence and luminescence?

The main difference between fluorescence and luminescence is that luminescence describes any process where photons are emitted without heat being the cause, whereas fluorescence is, in fact, a type of luminescence where a photon is initially absorbed, which causes the atom to be in an excited singlet state.

What is TTI in forensic science?

Transmitting terminal identifiers– fax machines use it as a header.

What is an obliteration in forensics?

obliteration. Act of making undecipherable or imperceptible by obscuring or wearing away. questioned document. Any signature, handwriting, typewriting, or other written mark whose source or authenticity is in dispute or uncertain.

Do some inks reflect infrared light?

Some of the writing materials, both: fluid or ball point, reflect all infrared radiations and these inks are called transparent to infrared radiations. Blue- black (iron based) and certain ball point inks, however, absorb and reflect these radiations to varying degrees.

What are the two types of luminescence?

The following are types of luminescence:

  • Chemiluminescence, the emission of light as a result of a chemical reaction.
  • Crystalloluminescence, produced during crystallization.
  • Electroluminescence, a result of an electric current passed through a substance.
  • Mechanoluminescence, a result of a mechanical action on a solid.

What are the types of luminescence?

Luminescence is caused by the movement of electrons into different energetic states. There are many different types of luminescence including bioluminescence, chemiluminescence, phosphorescence, and fluorescence. These various forms of luminescence differ in their method of emitting light.

What are the different types of luminescence?

What is the difference between incandescence and luminescence?

Luminescence is spontaneous emission of light by a substance not resulting from heat; or “cold light”. This distinguishes luminescence from incandescence, which is light emitted by a substance as a result of heating.

What are 5 types of Questioned Documents?

Some of the common types of questioned documents subjected to forensic document examination are stated below.

  • • Wills. • Cheques. • Bank Drafts. • Agreements. • Receipts.
  • • Identity Theft. • Forgeries. • Counterfeiting. • Suicides. • Homicides.
  • • Surface features. • Latent images. • Alterations. • Watermarks. • Ink stamps.

What is oblique lighting?

n. Illumination from an angle to review the relief of a surface; raking light. PhotographyA technique of illuminating a microscope specimen from the side, rather than by transmitted light.

What is infinfrared luminescence?

Infrared luminescence is a phenomenon similar to fluorescence under ultra­ violet light except that the emission occurs in the infrared rather than the visible part of the spectrum.

What is the medical definition of luminescence?

Medical Definition of luminescence : the low-temperature emission of light produced especially by physiological processes (as in the firefly), by chemical action, by friction, or by electrical action also : light produced by luminescence Other Words from luminescence

Can infrared luminescence be used in the examination of documents?

Infrared Luminescence in the Examination of Documents D. M. ELLEN and K. E. CREER Metropolitan Police Forensic Science Laboratory, 2 Richbell Place, London WCIN 3LA, England A description is given of a simple and easily constructed aid to the document examiner using infrared luminescence and certain necessary precautions are mentioned.

What is the difference between photoluminescence and radioluminecence?

Photoluminescence is a luminescence of a substance, excited by light, usually ultraviolet or visible. Radioluminescence is a luminescence caused by ionizing radiation. In a detailed analysis, cathodoluminescence, X-ray luminescence, and some other variants of radioluminescence are isolated.