Lighting onboard

Lighting

Introduction to lighting

Introduction to light

• Light is one of the electromagnetic wave which is in a range of visible wavelength

• Visible wavelength allow the light to be detected by the human eyes

• Unlike other wavelength such as ultraviolet rays, x-rays and gamma rays.

Multiple Select

What is the example of visible light?

• Torchlight

• Direct sun light

• UV rays

• Radiowave

Multiple Select

Is Light Emitting Diode (LED) is a visible light?

• Yes

• No

Lighting onboard

• Onboard, lighting are used for many applications

• The specified applications required a specified invention in order to ensure the reliability of the light and the safety of the crews.

Multiple Choice

What is the applications of light onboard?

• Accommodation light

• Emergency and navigational light

• General light

• All of the above

Illuminance is the area of the light is covered on an object or a surface.

Multiple Choice

What is the specific unit of the Illuminance?

• candela

• lux

• meter

• watt

Illuminance

• Is used to quantify intensity

• The higher the illuminance, the higher the intensity of light but smaller the area of the light covered on a surface.

As the distance of the light source from the ground increase, the illuminance will be decreased, the area of the light covered (beam width) is increased as well as the intensity of light were also decreased.

Multiple Choice

For a close space such as an engine room, the illuminance is?

• Lower

• Higher

Multiple Choice

For an open space such as deck area, the illuminance is?

• Lower

• Higher

Example of the illuminance level at certain area

Types of light bulb

• Incandescent bulb

• Tungsten-halogen bulb

• Gas discharge bulb

• Fluorescent bulb

Incandescent bulb

• The bulb is filled with the inert gas such as argon or nitrogen helps to reduce filament evaporation ensures an operating life expectancy of about 1000 hours

• When the current is pass through a wire filament, the temperature of the filament will be raised to around 3000 deg celcius, then it becomes incandescent and glows

Tungsten-halogen bulb

• Is an incandescent lamp that has a small amount of a halogen such as iodine or bromine added

• The combination of the halogen gas and the tungsten filament produces a halogen cycle chemical reaction which redeposits evaporated tungsten back onto the filament, increasing its life and maintaining the clarity of the envelope

• Thus, can be operated at a higher temperature than a standard gas-filled lamp.

Gas discharge bulb

• Gas-discharge lamps generate light by sending an electrical discharge through an ionized gas, a plasma.

• Use a noble gas; (argon, neon, krypton, and xenon) or a mixture of these gases. Some include additional substances, like mercury, sodium, and metal halides, which are vaporized during startup to become part of the gas mixture.

Gas discharge bulb

• In operation the gas is ionized, and free electrons, accelerated by the electric field in the tube, collide with gas atoms. Some electrons in the atomic orbitals of these atoms are excited by these collisions to a higher energy state. When the excited electron falls back to a lower energy state, it emits a photon of light of a characteristic frequency

Fluorescent bulb

• A fluorescent lamp or a fluorescent tube is a low pressure mercury-vapour gas-discharge lamp that uses fluorescence to produce visible light

Multiple Choice

Which one is true about incandescent bulb?

• The glass bulb is filled with noble such as xenon gas and some include additional substance such as mercury or sodium.

• It can be operated at higher temperature

• Halogen cycle chemical reaction occur

• The current heated the tungsten filament and become incandescent and glow

Multiple Choice

What are the gas filled in an incandescent bulb?

• Argon and nitrogen

• Argon or nitrogen

• Xenon or krypton

• Halogen

Multiple Select

Fluorescent bulb consist of?

• Phosphorus coating of glass tube

• Mercury

• Inert gas( Argon or Krypton)

• Electrodes

Multiple Choice

What is the substance moving in the tube when the voltage is supplied in?

• Electrons and charged argon molecules

• Only electrons

• Mercury

Multiple Choice

The electrical current also turn the mercury into?

• Solid particle

• Liquid substance

• Gas

Multiple Choice

How UV photon become visible in the fluorescent tube?

• When the mercury is become vaporized

• When it interact with phosphorus coating

• When it move from higher energy to lower energy levels

Multiple Choice

When the emergency lighting is being used?

• During fire

• During blackout

• During Flooding

• All of the above

Thank You

To be continued with navigational light sub topic