LST400 Ultrasonic Level Transmitter Operating Instruction

This document provides comprehensive operating instructions for the ABB LST400 ultrasonic level transmitter, covering quick start guides, parameter changes, installation, and configuration for distance, level, and open channel flow measurement. It details the non-contact ultrasonic measurement principle, keypad operation, fault finding, terminal connections, and various application examples including pump cycling and flow measurement with flumes and weirs.