🔍 Key Concepts

• Electromagnetic interference (EMI) and how it radiates or couples into wiring • Difference between tools that measure voltage/current and tools that detect radiated RF noise • How audio indication can help you locate a noisy source as you move around a space

💭 Think About

• Which of these tools could you easily carry around the vessel or aircraft and use to listen for changes in interference level as you move? • Which tools require direct electrical connection to a circuit versus simply sensing interference from a short distance away? • If EMI is being radiated like a small ‘transmitter,’ which instrument type is naturally designed to pick up that kind of signal?

✅ Before You Answer

• Identify which option is specifically designed to receive radio-frequency signals rather than measure circuit parameters at test points. • Check which tool can give a change in sound or indication as you move closer or farther from the EMI source. • Eliminate tools that must be wired into the circuit and can’t easily ‘sniff’ for interference in nearby space.