4th International Workshop on Measuring Techniques for Liquid Metal Flows (MTLM2024). including Summer School on Sodium handling, monitoring and instrumentation. Liquid metal cooling and liquid metal targets are innovative concepts to enhance efficiency and safety of the next generation IV nuclear reactors e.g., fast reactor cooling by sodium or lead and the use of lead-bismuth as target in a transmutation system. The safe and reliable operation of liquid metal systems requires adequate measuring systems and control units, both for the liquid metal single-phase flow as well as for bubble-laden liquid metal two-phase flows. Moreover, appropriate measuring techniques are an inevitable necessity to monitor, control and optimize industrial processes in metallurgy, casting, crystal growth etc.