A mercury vapor lamp is a type of gas-discharge lamp that utilizes mercury vapor as the primary source of illumination. It is a high-intensity, high-pressure lamp that functions based on the principle of electric discharge through a mixture of vaporized mercury and inert gases.
The lamp consists of a glass bulb containing an inner arc tube filled with mercury vapor, along with small amounts of argon or krypton gas. When an electrical current is applied to the lamp, typically through an electrode at each end, the gas mixture within the arc tube is ionized, initiating an electric discharge.
As the current passes through the lamp, the atomized mercury within the tube emits ultraviolet radiation due to the electrical excitation. This UV radiation then interacts with the phosphor coating on the inside of the bulb, causing it to fluoresce and emit visible light.
Mercury vapor lamps are known for their high lumen output, making them efficient sources of lighting for various applications such as street lighting, parking lots, and industrial facilities. However, they exhibit a bluish-white light that may affect color rendering, making them less suitable for applications requiring accurate color perception.
These lamps also require a warm-up time to reach full brightness and may not restart immediately after being turned off until the mercury has cooled down. Additionally, they contain mercury, a toxic element, and proper disposal procedures must be followed to avoid environmental contamination.
