![]() ![]() The US Postal Service began experimenting with fluorescent compounds sometime around 1954 these compounds were primarily phosphor based and glowed when exposed to ultraviolet (UV) light. As a repetitive task, this was well suited for a technology solution. Automated cancellers required the mail piece to be properly orientated so the cancel could be applied correctly. This is best for identification of Great Britain Machins and for US papers.Īs the postal service grew and evolved, the speed and efficiency of the cancelling process became paramount. ![]() Longwave UV is often used in leak detection (in conjunction with fluorescent dyes) and is useful for mineral studies. Longwave UV light, or black light, extends from 320 to 380 nm with a peak in energy at about 365 nm. Mediumwave UV lamps are generally used in electrophoresis documentation procedures and to identify minerals by their fluorescent response. Mediumwave UV light extends from 280 to 320 nm with a peak in energy at about 312 nm. It is also used for identifying US stamp tagging. Ultraviolet equipment that produces light in the shortwave region is typically used for toxicology, fluorochemistry, and germicidalĪpplications. For best results the shortwave UV source should be appropriately filtered (not unfiltered). Shortwave UV light extends from 180 to 280 nm with a peak in energy at about 254 nm. The ultraviolet spectrum ranges from 180 to 400 nanometers (nm) and is divided into three categories: Ultraviolet light (UV) is form of the electromagnetic spectrum that is adjacent to and greater in energy than visible light. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |