ADS420 Optical Dissolved Oxygen Sensor Operating Instruction

This document provides comprehensive operating instructions for the ABB ADS420 optical dissolved oxygen sensor, including safety precautions, calibration procedures, maintenance guidelines, and diagnostic troubleshooting. The sensor is designed for use with ABB multi-input transmitters like the AWT420 and AWT440, featuring hot-plugging capability and optional automatic in-situ cleaning with the EZClean compressed air supply unit.