A Power Quality Data Logger is an advanced electrical monitoring device used to record, store, and analyze power quality parameters over time. It continuously tracks important electrical values such as voltage, current, frequency, power factor, harmonics, and load variations. In Bangladesh, it is widely used in industries, power systems, and commercial facilities to ensure stable and efficient electrical performance. This device helps engineers collect long-term data to identify electrical issues such as voltage fluctuations, harmonic distortion, and load imbalance. By providing detailed historical and real-time data, it supports better decision-making for maintenance, energy optimization, and system improvement. Overall, it is an essential tool for monitoring and improving electrical power quality in modern systems.