Mercury vapour lamp

Types of Mercury Vapour Lamp

There are three main types of mercury vapour lamps, namely; clear, blue, and coated mercury vapour lamps. Each of the lamps has different uses and applications.

• Clear Mercury Vapour Lamps

  Clear mercury lamps are characterized by a simple construction. They have a tubular glass envelope that houses the arc tube filled with mercury and argon gas. The lamp operates by an electromagnetic ballast that controls the electric current flow. When power is turned on, the lamp produces a bright blue-white light. The illumination can be increased by using a higher wattage bulb. The lamps are available in different sizes and wattages. They are mostly preferred due to their high efficiency and long lifespan, which can last for up to 24,000 hours. They are commonly used in parking lots, street lighting, security lighting, and industrial lighting.

• Coated Mercury Vapour Lamp

  The metal halide light bulb, also known as the coated mercury vapor lamp, comes in different sizes and shapes. It is coated with phosphor powder on the inner wall of the glass envelope. The phosphor coating converts some of the blue-green light emitted by the mercury vapor into other colors. This lamp is more energy efficient than a clear mercury vapor lamp. It also produces light with a higher color rendering index (CRI). The bulb comes in a range of wattages and can last between 10,000 and 20,000 hours. The coated mercury vapor lamps are widely used in residential and commercial applications. These include floodlights, sport lights, and high bay lights.

• Blue Mercury Vapour Lamp

  The blue mercury vapour lamps are coated with a blue-tinted quartz. They are also known as black light mercury vapour lamps. The lamps emit ultraviolet (UV) light with a wavelength of 254 nanometers. Blue mercury vapour lamps are mostly used for indoor and outdoor plant growth, especially in greenhouses. They can also be used for swimming pool area lighting. They produce a dramatic effect by enhancing the appearance of water and the surrounding areas. Additionally, they are preferred for their energy efficiency and long lifespan, which can last for up to 2,000 hours.

Features and Functions of Mercury Vapour Lamp

Mercury vapor lamps are bulbs that produce light by passing an electric current through vaporized mercury gas, creating an arc between two electrodes. Here are the key components, features, and functions of mercury vapor lamps:

• Arc Tube

  The arc tube is a small glass tube that contains mercury and argon gas. It is where the electric current flows and produces light. The arc tube is the heart of the lamp and requires careful handling due to its fragile nature.

• Electrodes

  The electrodes are carbon rods that provide a path for the electric current. There are two electrodes in the arc tube: a positive electrode (anode) and a negative electrode (cathode). The electrodes are responsible for initiating the arc and maintaining it during lamp operation.

• Outer Bulb

  The outer bulb is a larger glass envelope that surrounds the arc tube. It helps diffuse and direct the light produced by the arc tube. The outer bulb also contains a coating of phosphor that converts some of the UV and visible light from the mercury arc into longer wavelengths.

• Base

  The base is the part of the lamp that connects to the socket. It provides electrical and mechanical connections. The base is usually made of metal and has a threaded or pin-style connection depending on the lamp type and application.

• Ballast

  A ballast is a device used to control the current flowing through the mercury vapor lamp. It provides the necessary voltage and regulates the current to maintain stable operation. Ballasts are typically electromagnetic or electronic.

• Color Coating

  Some mercury vapor lamps have a color coating on the outer bulb. This coating can be a phosphor blend that converts part of the ultraviolet (UV) and visible light produced by the mercury arc into longer wavelengths. It is especially useful for applications where specific colors or light intensities are needed.

Applications Mercury vapor lamps are widely used for outdoor lighting and industrial areas. Their applications include:

• Outdoor lighting in parking lots, street lights, and roadways.
• Industrial lighting in factory floors, warehouses, and work areas.
• Sports lighting in stadiums, arenas, and tennis courts.
• Security lighting in building perimeters, driveways, and entryways.
• Flood lighting in architectural site highlights and monument lighting.

Scenarios of Mercury Vapour Lamp

Mercury vapour lamps have several applications, especially in areas that require bright and efficient lighting. Here are some common scenarios where these lights are used:

• Outdoor Lighting

  Mercury vapour lamps are commonly used for outdoor lighting in the following areas:

  • Street lights
  • Parking lots and garages
  • Perimeter and security lighting
  • Building facades and architectural lighting
  • Sports fields and stadium lighting

• Commercial Lighting

  These lamps are extensively used in commercial settings due to their bright light output and efficiency. They are used in:

  • Warehouses and industrial facilities
  • Shopping malls and retail stores
  • Manufacturing plants
  • Workshops and garages
  • Factories

• Specialized Lighting

  Additionally, mercury vapour lamps are extensively used in specialized lighting applications. This includes:

  • Aquarium lighting, which provides the necessary illumination for fish and aquatic plants.
  • Horticultural lighting, which promotes the growth of plants in greenhouses and indoor gardens.
  • UV curing lights in industrial applications, which utilize the ultraviolet radiation emitted by mercury vapour lamps to cure inks, coatings, and adhesives.

• Emergency Lighting

  Some emergency lighting systems employ mercury vapour lamps due to their high visibility and brightness.

• High Ceilings

  These lamps are ideal for areas with high ceilings, such as gymnasiums and aircraft hangars, since they provide uniform and strong illumination.

How to choose mercury vapour lamp

When purchasing a mercury vapor lamp, there are a few things to consider to ensure the right choice. Here are some of them:

• Consider the application

  Decide on the use of the lamp to help determine the appropriate type and specifications. Whether for residential landscaping, commercial outdoor lighting, or industrial applications, each has specific requirements and appropriate lamp types.

• Consider the color temperature and rendering

  Choose a lamp with a color temperature that produces the desired ambiance. For warmer tones, look for 3000K, while 5000K is for cooler, more energizing light. Also, consider the color rendering index (CRI), which indicates how accurately the light source displays colors. A higher CRI is better for applications such as outdoor areas and parking lots.

• Consider the lamp's lifespan and maintenance

  Look for options that offer a longer lifespan and lower maintenance requirements. Generally, higher quality lamps have a longer lifespan and reduced maintenance.

• Consider the lamp's compatibility

  Ensure that the selected mercury vapor lamp is compatible with existing fixtures and equipment. This is especially important for those planning to replace an old lamp with a new one.

• Consider the quality and brand

  It is very important to choose a reputable brand known for producing quality products. Although this may seem like a small factor, it will significantly affect the lamp's performance and reliability.

mercury vapour lamp Q & A

Q1. Can a mercury vapour lamp be used for indoor plants?

A1. Mercury vapour lamps are not recommended for indoor plants because they emit a lot of red and far light. They do not have the full spectrum of light needed for photosynthesis.

Q2. Do mercury vapour lamps get hotter than other types of bulbs?

A2. Yes, mercury vapour lamps tend to get hotter than other types of bulbs. They should be installed at a safe height to avoid the risk of burns or fire hazards.

Q3. How long does a mercury vapour lamp take to reach its maximum brightness?

A3. A mercury vapour lamp takes about 2 to 3 minutes to reach its maximum brightness. Unlike other bulbs, they do not achieve their maximum brightness instantly.

Q4. What are the common signs that a mercury vapour lamp is failing?

A4. The common signs that a mercury vapour lamp is failing include flickering, dimming, or uneven light output. The lamp may also produce a buzzing sound. In cases, it may have dark spots on the glass.

Q5. Is it possible to recycle mercury vapour lamps?

A5. Yes, it is possible to recycle mercury vapour lamps. They need to be handled and disposed of properly due to their mercury content. Consult local regulations to get detailed information on the recycling and disposal process.