Identify the gas discharge lamp.

Identify the gas discharge lamp.

• A. HMI
• B. LED
• C. Tungsten
• D. Fluorescent

Answer: (A)

Gas discharge lamps produce light by creating an electric arc inside a gas or vapor. The HMI lamp fits this description because it uses an arc tube filled with mercury vapor and metal halides; when energized, the arc emits a very bright, daylight-colored light and it’s designed for high intensity. It also requires a ballast to start and regulate the current. LEDs are solid-state diodes that emit light directly from a semiconductor, not from a gas arc. Tungsten lamps are incandescent, producing light by heating a filament. Fluorescent lamps also use a gas discharge (mercury vapor) to generate UV light, which then excites a phosphor coating to emit visible light, typically with lower brightness than an HMI.

Gas discharge lamps produce light by creating an electric arc inside a gas or vapor. The HMI lamp fits this description because it uses an arc tube filled with mercury vapor and metal halides; when energized, the arc emits a very bright, daylight-colored light and it’s designed for high intensity. It also requires a ballast to start and regulate the current.

LEDs are solid-state diodes that emit light directly from a semiconductor, not from a gas arc. Tungsten lamps are incandescent, producing light by heating a filament. Fluorescent lamps also use a gas discharge (mercury vapor) to generate UV light, which then excites a phosphor coating to emit visible light, typically with lower brightness than an HMI.