Machine & UV
UV-visible elements
Areas invisible in ordinary light that emit visible light under an ultraviolet lamp.
Ultraviolet light lies outside the range of human vision. Certain areas of the note absorb it and emit it again at a wavelength the eye can see — which is why they appear only while the lamp is on.
- In ordinary room light, the area looks no different from its surroundings.
- An ultraviolet lamp emits light the eye cannot see, and the area re-emits light at a wavelength that it can.
What to observe
- Under an ultraviolet lamp, certain areas glow while the rest of the sheet stays dark.
- This check needs equipment, which is why it sits outside the three 3D steps. Bank Indonesia built 3D precisely from checks that need no equipment at all.
This page explains how to check a feature, not how one is produced. Nor does this site say whether any note is genuine — that authority rests with Bank Indonesia.
Switch the lamp on
Two states, shown side by side: ordinary room light, then under ultraviolet. The change is a state change, not an animation.
A screen emits no ultraviolet. What is shown here is a picture of the result, and cannot stand in for a real UV lamp.
Sources
- Artech House — R. L. van Renesse, Optical Document Security, 3rd edition (2005), Ch. 7, Luminescent features
- Pearson — Eugene Hecht, Optics, 5th edition (2017), §3.7, The electromagnetic spectrum