When sourcing a Power Quality Analyzer (PQA), you must prioritize Measurement Accuracy and Sampling Rate. Ensure the device complies with IEC 61000-4-30 Class A standards for professional-grade logging. Key specs include a sampling rate of at least 256 samples per cycle to capture transients, support for Harmonic Analysis up to the 50th order, and the ability to measure Swells, Dips, and Interruptions. Additionally, verify the Memory Capacity for long-term data logging and the inclusion of Flexible Current Clamps (Rogowski coils) for easy installation in tight electrical panels.