👉 Scale fluid, also known as a scale mass or specific gravity fluid, is a substance used in fluid mechanics and engineering to measure the density of fluids. It's essentially a standardized fluid with a known and consistent density, typically water, which serves as a reference. By comparing the mass of a fluid sample to the mass of the scale fluid displaced when it's submerged, engineers can calculate the fluid's density. This is crucial for understanding fluid behavior in various applications, from pipeline design to chemical processing, ensuring accurate measurements and efficient system performance.