UV Lamp Technologies2

UV Lamp Technologies2UV Lamp Technologies2UV Lamp Technologies2UV Lamp Technologies2UV Lamp Technologies2UV Lamp Technologies2

How do UV Lamps Work?

1. Power is applied to the lamp electrodes.
2. An electrical arc is generated from ionized gas, or gas mixtures which conduct electricity.
3. Current is limited from the power source to protect the lamp and supply wiring.
4. As the arc temperature rises, mercury in the lamp converts to a gaseous vapor state.
5. Mercury vapor conducts electricity, completing the circuit.
6. Lamp output in the UV range depends on the amount of mercury and vapor pressure of mercury in the lamp.

What's the Difference Between Low Pressure (LP), Amalgam Low Pressure (LP), and Medium Pressure (MP) UV Lamps?

Low Pressure (LP), Amalgam Low Pressure (LP) and Medium Pressure (MP) lamps are all mercury-based lamps. They differ primarily by electrical excitation and ionization levels of the mercury within the lamp and corresponding internal pressures.

Your application requirements will dictate the selection of lamp technology you choose, and will depend on the requirements of each specific site.

Some Key Differences Between Lamps

• Conventional low-pressure and amalgam lamps are significantly more energy efficient than medium pressure lamps.
• Medium pressure lamps produce the greatest UV output per unit length of lamp of the 3 lamp types.
• New high power amalgam lamps are significantly more powerful than low pressure lamps.
• Even though more cleaning may be required for medium and amalgam lamp-based systems, because they have a smaller number of lamps in the UV unit, these systems can cost-effectively incorporate automatic cleaning systems to remove fouling. These automatic cleaning systems can thereby significantly reduce labor associated with lamp maintenance.
• Polychromatic light has many different wavelengths, even beyond the disinfection range of 220nm to 280nm that can have positive and/or negative effects on the fluid being treated.

uvaquafine Standard Low Pressure (LP) and Amalgam Low Pressure (LP) Lamp Spectrum

Facts About uvaquafine Standard Low Pressure (LP) Lamps

• uvaquafine LP Lamps are considered to be monochromatic or 'single peak output' lamps.
• LP lamps operate at about 40°C and have one useful disinfection output peak at 254nm.
• Roughly 40% of the electrical energy imparted into the lamp becomes UV-C energy of the 254nm wavelength.
• LP lamps have the lowest internal pressure and have the lowest power density per unit length of lamp arc.
• Due to the very low temperatures that LP lamps operate at - fouling of the quartz sleeves is typically not a large issue, even in relatively low UV Transmittance (UVT) fluids.
• Cleaning requires the least maintenance of the 3 lamp types.

Facts about uvaquafine Amalgam Low Pressure (LP) Lamps

• Like Standard LP lamps, Amalgam LP lamps are considered to be monochromatic with a significant 254nm output peak.
• uvaquafine Amalgam LP lamps combine mercury with another element - allowing them to operate at higher temperatures - roughly 100°C.
• Roughly 35% of the electrical energy imparted into the lamp becomes UV-C energy of the 254nm wavelength.
• Operating at higher temperatures and pressures allow for an increased power density of roughly 1.5 - 4x of a lower pressure lamp per unit of arc length.
• Also because of slightly higher 100°C temperatures that these lamps operate at, fouling may be slightly more than that of a low pressure system - but it is typically not a major issue.

Facts About uvaquafine Medium Pressure (MP) Lamps

uvaquafine Medium Pressure (MP) Lamp Spectrum

• uvaquafine MP lamps are considered to be polychromatic lamps, due to their wide output spectrum.
• MP lamps operate at roughly 800°C - 900°C.
• With an average of 10x the power density per unit arc length, uvaquafine MP lamps have significantly higher power compared to Amalgam LP lamps.
• Only 11-12% of the electrical energy imparted into the MP lamp becomes UV-C energy, with a range of 220nm to 280nm.
• MP lamps invariable require an automated cleaning system, as manual cleaning of these systems tends to be labor intensive and frequent.

Further Reading

Download our UV Lamp Technologies pdf for further information, including:

• UV Spectrum for Organism Inactivation information
• Application Needs examples and chart
• Quartz Sleeve Fouling Performance Information
• Cost, Maintenance and sustainability Comparisons Between Lamps

UV Lamp Technologies pdf [pdf: 594 KB]