 Hydrargyrum medium-arc iodide lamp

A Hydrargyrum medium-arc iodide lamp, commonly known as an HMI (Hydrargyrum Medium-Arc Iodide) lamp, is a type of high-intensity discharge (HID) lamp that produces a bright, white light. These lamps use a combination of mercury (hydrargyrum is the Latin name for mercury) and halide salts, specifically iodine, to generate light.