This guide explains how to correctly measure DC current in PV systems, what to watch out for, and how to obtain reliable results in real-world solar applications. In a PV system, DC current is measured by clamping a DC-capable clamp meter around a single DC conductor. Traditionally used by electricians for measuring current without breaking the circuit, a modern clamp meter, particularly one with DC voltage. Unlike traditional inline measurements, a DC clamp meter allows you to measure current safely without disconnecting the circuit, making it the preferred tool for live PV systems. This helps determine the panel's efficiency and identify any performance issues. Testing is usually conducted under standardized conditions to ensure accurate results. You may also use an IV curve. A clamp meter is a clothespin-shaped instrument that can be clamped around a live wire in order to measure the current it's carrying.