The particulate properties of multiphase flows are crucial in various process engineering applications, including food processing, pharmaceuticals, and chemical production. Currently, the industry lacks reliable measurement techniques that can accurately capture these properties with the necessary temporal and spatial resolution. As a result, process development often relies on experience, safety factors, and rules of thumb. Different measurement techniques are available, each with unique advantages and limitations. Recently, image-based incident light probes have emerged as a promising method, offering insights into the apparatus for nearly any substance system. However, challenges such as distance-dependent imaging, low depth of field, and poor contrast due to reflections can introduce errors that are only partially mitigated by complex image processing. The Optical Multimode Online Probe (OMOP) addresses these issues. This thesis employs telecentric shadowgraphic probes based on the OMOP to measure particulate properties across various applications. Four case studies demonstrate the effectiveness of the OMOP in a bubble column, crystallizer, stirred vessel dispersion, and two-phase pump-mixer, confirming that shadowgraphic probes can reliably measure particle size across different processes.
