When sourcing multimeters, prioritize the Measurement Category (CAT) rating, such as CAT III 600V or CAT IV 1000V, to ensure safety for the intended electrical environment. Look for True RMS (Root Mean Square) capability, which is essential for accurate AC voltage and current readings on non-linear loads. Additionally, evaluate the Display Counts (e.g., 2000, 6000, or 20000 counts); higher counts provide better resolution for precise measurements. For industrial use, ensure the device features Auto-ranging and a high input impedance (typically 10MΩ) to prevent circuit loading.