Power Engineering 3

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Power Engineering 3

• 1. Radiation, Visible Radiation, Light,
  Physiology of Vision, Physics of Light,
  Photometric Values
• 2. Lighting Measurements (illuminance,
  luminance, luminous flux, luminous intensity)
• 3. Light Sources
• 4. Luminaires
• 5. The Principles of Interior Lighting
• 6. Lighting Systems
• 7. Lighting system calculations methods

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Visible Radiationand Light
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transfer of energy through a space in the form
of electromagnetic waves or particles

Radiation
Natural source of electromagnetic radiation is Sun
The Light Technique does not examine essence
either force effects or continuousness of
radiationbut watching the distribution of the
energy flows
in the smooth transitions between the considered
sites.
Decisive is the energy transmitted by radiation
for 1 s power transmitted by radiation
radiant flux Fe dWe / dt (W)
Any radiation can be decomposed into components
with sinusoidal course.
Every component is characterized by
certain frequency n (Hz) monofrequency
radiation or wavelength l
Wavelength l is usually expressed in nm 10-6
m or in mm 10-9 m l depends on the
speed of radiation propagation ? in vacuum
l c0 n -1 (m ms-1, Hz) speed of the
electromagnetic wave propagation in vacuum c0
2,998 108 ms-1
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Components of radiation sorted by frequency or
wavelength
RADIATION SPECTRUM
Visible radiation (VIS) 380 770 nm
radiation capable of eliciting visual sensation
(perception)
ultraviolet
UV
Optical radiation
VIS
visible
IR
infrared
The electromagnetic spectrumindicatively sorted
by frequencies and wavelengths
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Light in the Course of History
Physical view

• Some Greek philosophers Ptolemaios (70 147
  B.C.) thought that the rays of light come from
  eye.
• Among the opponents of this idea was for example
  Demokritos (460 - 432 B.C.) He said that the
  vision is conditional on slight indestructible
  bodies, which are coming out of the observed
  objects and hit the surface of the eye.

Until the turn of 17th and 18th century appear
competing theory about the nature of light

• Isaac Newton (1643 1727 English physicist)
  viewed light as a stream of point particles of
  different sizes emanating from glowing objects
  and hitting the eye. This results in a sensation
  of light.
  corpuscular theory
  When the impact at the interface with a denser
  medium
  smaller particles are deflecting more, bigger
  less.

• Cristiaan Huygens (1629 1695 Dutch
  mathematician and scientist) Considered light as
  a longitude waves of special environment filling
  the entire space.
• wave theory This enabled
  explain interference of rays and bending of light.

The wave theory was verified even by the French
physicist Étienne-Louis Malus (1775 -1812) who
converted it into a analytical form (1808).
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Light in the Course of History
Break of the looking at light 1873

• James Clerc Maxwell (1831-1879) Scottish
  physicist
• unified theory of electrical a magnetic effects
• presented a general mathematical description of
  the electromagnetic field Maxwells
  equations
• author of the theory of electromagnetic origin
  of light
• speed of propagation of an elmag field is
  approx. that of the speed of light
• in vacuum electromagnetic waves are always
  transvers
• light is elmag waves of the certain wavelengths
  perceived by human vision

Maxwells theory accurately reproduced the
available experimental data. At the atomic level
it had to be clarified by quantum electrodynamics.

• Albert Einstein (1879 1955) German-born
  theoretical physicist
• showed that the light has together properties
  wavelength as well as corpuscular
• dual character of light
• Introduced the concept of the photon discovered
  regularities of the photoelectric effect
• Put the foundations of quantum theory of light
• Is the author of theory of relativity

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Light
Visible radiation evaluated by the vision of
observer according to the spectral sensitivity of
the eye to radiation of different wavelengths
relative spectral sensitivity of the eye s(l)for
the normal photometric observer
1,0 0,9 0,8 0,7 0,6 0,5 0,4 0,3 0,2 0,1
0
s(l)
Day vision
Night vision
400 500
600
700
wavelength (nm)
Wavelength region of the visible light
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Light radiation
Visible radiation evaluated by the vision of
observer according to the spectral sensitivity of
the eye to radiation of different wavelengths
In the visible region of the spectrum gives each
monofrequency radiation completely certain color
sensation ? monochromatic radiation
Illustrative distribution of tones in the
spectral range of visible radiation.
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Visible radiation
Light factor of making the environment

visual perception light influence

overal wellbeing
By vision man gets 80 to 90 of all
information By consuming for that up to 25 of
energy intake
Goal by good lighting create visual comfort of
observer
Visual comfort ? vision works optimally
good vision and differentiation ? man feels
mentally well, environment has a pleasant impact
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Lighting

• Appropriate
• Higher productivity
• Growing also production quality
• Higher safety
• Fatigue grows more slowly
• Easier recovery

• Inappropriate
• Increase the number of failures
• Decrease the production quality
• Rise in the number of accidents
• Higher eye fatigue
• Increasing overall fatigue

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Influence and Impact of Optical Radiation
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Influence and impact of optical radiation
Light - means to transfer and obtain visual
information about the surrounding environment
Good lighting is meant for
visual performance
task difficulty
pleasant environment subjective
feelings psychological aspects
visual comfort
personal safety
accidents, feel safe
Light is important factor of creation of
environment
Inappropriate lighting
eye fatigue
Burning eyes, headache
Body/organism overload alarm
overal organism fatigue
Common causes of errors
glare
Injuries, accidents
inconsistency with the illumination level
incorrect color corelated temperature of light
sources
wrong color resolution
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Light controls our biological processes
Many of the processes taking place in about 24 h
(ie. circadian) cycles
Depending on the rotation of the Earth around the
Sun
active phase during the day resting phase
during the night
For example body temperature, blood pressure,
pulse rate, metabolism, immune function, sexual
function, physical and mental activity
Light govern our inner clock sensor third type
of photoreceptor C
Relative spectral sensitivity C circadian
sensor V Eye for the day vision
(prevail cones) V Eye for the night
vision (prevail rods)
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The basic circadian cycle periodic alternation
of light and darkness
Central biological clock also controls the
peripheral clocks of individual organs,
especially the lungs, kidneys, heart and
pancreas, etc. ? Therefore, changes in the
activity of human organism and accompanying
changes in temperature, blood pressure, heart
rate, etc.
A typical daily rhythm of changes in the levels
hormones melatonin and cortisol along with
corresponding changes in body temperature and
degree of human activity.
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The consequences of disruption of biorhythms
- discomfort - sleep disorders - serious illness
Examples of causes

• rapid shifts between time zones (jet lag)
• work in alternate or night shifts
• long-term stay in an environment with very low
  levels of illuminance

Some resident especially of big cities, mainly
during the winter time can suffer from seasonal
affective disorder - SAD
(e.g. Approx. 10 New York citizens)
Consequences - reduction of working, social
and sexual activity -
feelings of sleepiness during the day
- changes in behavior of individuals in
groups - weight gain
- processes reminiscent of the
events during the animals winter sleep
- for evolving organisms up to
suppression of some organs development
Improvement - repetitive illumination by
levels 2 500 lx 2 h/day

10 000 lx 0,5 h/day
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Body Blues illness
Expressions - vegetative depressive
symptoms - difficulty in concentrating -
feeling a lack of energy - feeling of anxiety
up to depression - sexual aversion - sleep
disorders (sleepiness during the day) -
irritation - increased sensitivity to criticism
Major cause low level of the tissue hormone
serotonin (hormone of happiness)
participates in brain processes related to the
occurrence of a mood
Relief carbohydrates after 1 h sharply drop
of mood patients overeat sweets and gain weight
Illness 3x more often at women much slower
reproduction of serotonin than men Expert
estimate in the world disease affects
approximately 1 million women
Therapy minerals, vitamins B1, B2, B6, D,
selenium, folic acid Staying in a pleasant
environment with a higher level of illuminance
? Often compensation of the lack of light by
suitable intense lighting even for a rearing of
farm animals (e.g. stables) to ensure normal
growth for evolving organisms of young ones.
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Research of the response of the brain centers to
external light stimuli received by sight
By exposing to light of certain color and
suitable frequency of its flickering it is
possible to stimulate certain brain centers
Use prevention and treatment of certain
diseases especially of psychological nature
Constructed devices, elaborated procedures and
instructions patient observes (cca 20 min)
defined field of view, where for the
selected period (3, 5, 10 min) in
the certain rhythm ( f 8, 10, 12 Hz)
the light of certain luminance and color is
flickering for the one procedure it is
applied e.g. 3 alternatives each procedure
is pre-programmed by the doctors prescription
Research is still continue in the framework of
the CIE The Effects of Dynamic and Stereo
Visual Images on Human Health
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Another possible use of visible radiation
treatment of infant hepatitis by irradiation of
infants with blue light of metal halide lamps
photosynthesis provides the basic cycle of
substances on Earth, life would not exist without
it. Exposure to visible radiation occurs in the
green parts of plants for the presence of
chlorophyll (leaf green) as a catalyst a chemical
process (photosynthesis), wherein carbon dioxide
and water are formed into organic compounds.

optics photography electrical engineering
chemistry And other fields.
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Ultraviolet radiation (UV)
UV-A 315 - 400 nm
UV-B 280 - 315 nm
UV sources Sun, artificial light sources
(especially Hg discharge lamps)
UV rays pass well through water, quartz, some
glass (e.g. potassium phosphate), organic glass
and air UV rays will not pass through even a
thin layer of metal ordinary glass (esp.
leaded), discharge lamps bulbs for general
lighting pass only min UV
UV-C 100 - 280 nm
If there is no significant breakdown of the ozone
layer, then a high layer of air in the atmosphere
practically absorb UV radiation from the Sun.
In our climate zone the UV radiation reach the
Earths surface only on a sunny day at the high
mountains.
Some materials (fabrics, prints, paintings, etc.)
after irradiation with higher doses of UV aging
faster, lose color, or may undermine their
structure and mechanical strength.
Pigmentary effects (protective browning) 297
nm, 340 nm. At higher doses vessel expansion,
short-term inflammatory reddening of the skin
(erythema). Erythemal effects esp. dangerous to
mucous membranes.
Intense UV irradiation of the skin can cause
serious disease, even cancer.
UV radiation excites phosphor luminescence use
at the fluorescent lamps to fluorescent analysis
etc.
UV around 283 nm supports the production of
vitamin D - accelerates the deposition of calcium
in the bones Treating a number of diseases
(rickets, sinusitis, metabolic disorders, TB,
skin, etc.) Source high pressure Hg discharge
lamps mountain sun.
Germicidal effects (265, 254 nm) destruction of
bacterial viruses etc., sterilization of air,
liquids and solids. Special germicidal lamps.
Wide use in medicine, industry and agriculture
(e.g. against molds).
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Infrared radiation (IR)
IR-A 780 - 1400 nm
IR-B 1400 - 3000 nm
IR carrier of radiant heat Use heating,
warming, drying IR sources Sun, warm housing,
infrabulbs, others
IR-C 3000 - 106 nm
IR easily pass through air, fog
thin layers of metal etc.
very little pass through glass (esp.
containing oxides Fe) water, thermal insulators
IR-A penetrates the skin, dilates blood
vessels, improves blood flow, accelerates
healing, soothes pain
- use for treating of various diseases
(including rheumatic problems) - diathermy

• infraphotography
• thermal imager (observation at night
  converting to the visible light)

Another use of IR
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Thank you for your attention