Variomats

Variomats are a type of variable area flow meter. They are designed to measure the flow rate of liquids or gases. The core principle of a Variomat is a tapered tube and a float that moves freely within it. As the flow rate increases, the fluid pushes the float higher up the tube. The cross-sectional area between the float and the tube wall increases with height. This means that the velocity of the fluid actually decreases as it moves past the float. The flow rate is indicated by the position of the float within the calibrated tube. The markings on the tube correspond to specific flow rates.

Variomats are often used in applications where a simple, reliable, and cost-effective flow measurement is required. They do not need external power to operate, making them suitable for remote locations or situations where electricity is unavailable. Their construction is typically robust, often made from glass, metal, or plastic. Calibration is usually done at the factory and is specific to the fluid and operating conditions. While generally accurate for their intended purpose, Variomats can be sensitive to changes in fluid density, viscosity, and temperature, which can affect the float's buoyancy and the fluid's behavior. They are commonly found in industrial processes, HVAC systems, and laboratory equipment.