Ultraviolet rays are invisible rays that are part of the energy from the sun. Some animals can see UV rays. UV rays have short wavelengths between 400 nm and 10 nm. There are three types of UV rays - UV A, UV B, and UV C - which have different wavelength ranges and properties. UV rays can have both beneficial and harmful effects on humans and are used in various applications like water disinfection, sterilization, and counterfeit money detection.

2. What is
Ultraviolet
rays ?
Ultraviolet rays is invisible
rays, that are part of
energy coming from the
sun but some animal can
see the ultraviolet rays
such as bird and insect.
Ultraviolet rays has
wavelength in range :
400 nm to 10 nm
(4 x 10-7m to 10-8m)
Ultraviolet wave rays
has frequency in range :
1015 - 1016 Hz

3. • In 1801 the Germany physicist Johann
Wilhelm Ritter made the observation using
silver chloride by exposed the colours of
visible which he created by passing the
sunlight through the glass prism, that the
silver chloride darkened. He found an
intense (more quickly) reaction with the
silver chloride at beyond the end of violet
(visible light) and it’s called as “ultraviolet
light”.
• “Ultraviolet” means “beyond violet” (from
Latin : Ultra = “beyond”)

5. UV A UV B UV C
Wavelength
Range
400 nm–315 nm 315 nm–280 nm 280 nm-100 nm
Alternative Names Long wave, black
light
Medium wave Short
wave, germicidal
KIND OF UV

6. UV A
 Wavelength Range : 400 nm–315 nm
 Alternative Names : Long wave, black light, not absorbed by the ozone layer
 Benefits Effect :Helps in the production of Vitamin D in the human’s body.
Provitamin D will be produced in hypodermis in the bottom of
dermical layer in skin.
 Harmful Effect : May darkened skin color because UV A stimulates the melanosit
of the skin to produce more brown pigments (melanin)
 Application : 1. Checking of counterfeit banknotes.
2. Hardening of inks and coating.
3. Pest control. Insects are attracted to the UV light and killed by
the electric shock in bug zappers.
epidermis
dermis
hypodermis

7.  Wavelength Range : 315 nm–280 nm
 Alternative Names : Medium wave, mostly absorbed by the ozone layer but not
until the earth’s surface
 Benefits Effect : Helps in the treatment of psoriasis (disease causing red and scaly
skins).
 Harmful Effect : May cause sunburn on the skin
 Application : Medical applications such as treatment of psoriasis (a kind of disease
causing red and scaly skins).
UV B

8.  Wavelength Range : 280 nm-100 nm
 Alternative Names : Short wave, germicidal, completely absorbed by the ozone
layer and atmosphere
 Benefits Effect : Desinfection of drinking water and sterilization of apparatus by
damaging the DNA of bacteria (germs).
 Harmful Effect : May cause skin cancer and skin damage
 Application : Disinfection of drinking water and sterilization of apparatus. Energy
UV radiation destroys the DNA of bacteria and micro-organism.
UV C

9. UV A : From the sun to the earth
UV B : From the sun to the
ozone layer
UV C : From the sun
to the mesosfer
The discrete
spectrum of
wavelengths based
on the difficulties
of atom to
excitate.

10. 1. Kill the microorganism.
Such as : Laminar Air Flow with
Ultraviolet
2. Spectrophotometer UV
3. Money detector

11. This spectophotometer is used to meassure
the ultraviolet rays absorption by the colourless
solution sample. This spectrophotometer is’nt
used to meassure colour solution absorption.

21. The feast is usually more widespread
circulation of counterfeit currency. Well, in
anticipation that you could use counterfeit
money detector practical.
This counterfeit money detector using UV
light that is able to distinguish real money
with fake money. Under exposure to
ultraviolet light, the original serial number
will change the color of money. In
addition, the real money is also printed
using a special ink that will appear
invisible when illuminated its nominal
value. Thus, counterfeit currency detector
is able to work accurately.
How to use counterfeit money detector is
also very easy. Simply press the button to
turn on the UV light, then shine on the
money. You can already see the
difference even counterfeit money that
may be missed by the naked eye.