How is a rotameter primarily utilized in process instrumentation?

A rotameter is primarily utilized in process instrumentation to indicate flow rate. This device operates on a float that rises and falls within a tapered tube as the flow of liquid or gas passes through. The position of the float corresponds to the flow rate, which can be read directly off a scale on the rotameter. The design allows for the measurement of varying flows across a wide range and provides a simple, visually interpretable indication of flow without requiring power or extensive calibration.

This characteristic makes the rotameter particularly valuable in many industrial applications, as it gives operators an immediate visual representation of flow conditions. Different flow rates will position the float at different heights within the tube, allowing for accurate and quick assessments of how much fluid is passing through a system at any given time.