What is the best tool to diagnose intermittent problems in a low-voltage DC circuit?

A digital storage oscilloscope is the best tool for diagnosing intermittent problems in a low-voltage DC circuit because it provides a clear visual representation of voltage changes over time. Intermittent issues often manifest as sporadic disturbances in the circuit's voltage levels, and a digital storage oscilloscope can capture these transient events, allowing technicians to see how the signals occur in real-time.

Unlike a standard multimeter or digital multimeter—which typically measure voltage, current, and resistance but do not show the waveform or timing of voltage changes—an oscilloscope can display the actual waveform, helping to pinpoint the exact moment and nature of the intermittent fault. This level of detail is crucial for diagnosing issues that may not be present during static testing or may fluctuate rapidly.

Clamp meters are useful for measuring current in a circuit but do not offer the detailed voltage-time relationship analysis that is essential for diagnosing intermittent problems.