Lighting (1) Flashcards
Define Invisible light
a very energetic form of light, invisible to the human eye
what unit is wavelength measured?
nanometers or angstroms
Ultraviolet lights wavelength in nanometers:
under or below 400 nanometers
Ultraviolet light categories
- UV-A
- UV-B
- UV-C
The ____ the wavelength the more _____ that is carried in the light and the more ____ it is to the human cells.
shorter wavelength
more energy
more dangerous
UV-A
320-400 nm
(black light)
- peak performance at 365 nm
high intensities:
- blurred vision
- increased risk of cataracts
UV-B
280-320 nm
(mid-wave UV)
- sunburn
- snow blindness (eye damage)
UV-C
100-280 nm
(short-wave UV)
- sterilization
- severe burns
- eye damage
Inspection lighting variables:
UV-A 365nm
energizes fluorescent dyes (550nm yellow-green)
How does fluorescence work?
the process of converting one wavelength to a new wavelength.
365 nm - 550 nm
UV inspection light energy ranges
2000 to greater than 10,000μW/cm²
Types of UV lighting equipment:
- Mercury Vapor-Arc Lamps
- LED’s
- Overhead low pressure tubes
- overhead metal halide flood lights
Parts of a Mercury vapour-arc lamp
- pressurized quartz tube
- starting electrode
- resistor
- electrodes
- vacuum or inert gas
- bulb
Light intensity requirement
no less than 1000μW/cm² at 15in from inspection surface
Mercury vapor-arc lamps 100watt bulbs can be capable of producing how much intensity at 2inches from inspection surface?
30,000μW/cm²
