Water content in fresh concrete is well known as an important parameter in concrete technology. It has a decisive influence on essential material properties, such as processability, strength and durability. Special requirements, for example, uniformity with facing concrete surfaces, also call for constant monitoring and targeted management of this parameter. It is thus, or would be, an advantage to have efficient methods for recording water content in fresh concrete in real time in ongoing production. Various measuring instruments are currently available on the market for this task. In laboratory investigations at the TH Cologne, Germany, a mobile, manually operated probe with microwave technology was selected and assessed as regards concrete technology factors influencing its measurement results. The first results indicate that, under certain technological boundary conditions, this measurement method is basically suitable for estimating and evaluating deviations in water content with successive supplies of concrete.