Moisture measurement in oil refers to technologies and devices used to monitor water content in oil, crucial for industries like power generation, manufacturing, and automotive. Companies like Michell Instruments (UK) and Vaisala (Finland) specialize in such solutions, offering products like hygrometers, sensors, and online analyzers to ensure oil quality and equipment longevity. These tools help prevent corrosion and inefficiencies in hydraulic systems, transformers, and lubrication processes.