NALMCO Certified Apprentice Lighting Technician (CALT) Practice Exam

Which of the following is not a fluorescent lamp type?

1. Preheat

2. Metal halide

3. Rapid start

4. Instant start

The correct answer is: Metal halide

Metal halide lamps are a type of high-intensity discharge (HID) lamp and are not classified as fluorescent lamps. They work by creating an arc through vaporized metal halides and other gases to produce light, whereas fluorescent lamps operate on a different principle that involves the excitation of mercury vapor to generate ultraviolet light, which then interacts with a phosphor coating inside the lamp to produce visible light. In contrast, the other types listed—preheat, rapid start, and instant start—are all specific variants of fluorescent lamps. Preheat lamps require a starter to preheat the electrodes before the lamp ignites, while rapid start lamps use a low-temperature heat at the electrodes to facilitate easier starting without a starter. Instant start lamps ignite immediately when power is applied, making them more energy-efficient at startup. Understanding these differences is crucial for recognizing lamp types and their applications in lighting systems.