Which of the following is NOT listed as a TIC emitter category?

• A. PAD
• B. Passive
• C. Indirect
• D. Active

Answer: (C)

Think of TIC emitter categories as the ways a detector interacts with energy on the scene. Some emit energy themselves and are labeled as active emitters. Others don’t generate energy but respond to energy already present in the environment, so they’re passive emitters. PAD represents another recognized category in this system, describing a specific emission/detection mode used with TICs. Indirect isn’t part of this established set of categories, so it isn’t listed. Knowing these categories helps you predict how a TIC will behave in different situations and how to use it safely and effectively.