What type of flow measurement does a Thorpe Tube provide?

A Thorpe Tube is specifically designed to provide true flow measurement of gases. It functions based on the principle of variable orifice flow, where a float rises in a calibrated tube as gas flows through it. The position of the float, which is directly related to the gas flow rate, allows for accurate measurement of the flow in real-time. This design ensures that the flow measurement is independent of the pressure drop across the device, making it a reliable method for assessing the actual flow rate of medical gases in a clinical setting.

True flow measurement is critical in medical applications as it ensures that patients receive the precise amount of gas needed for therapeutic purposes. The other options, while they might suggest different types of measurement, do not accurately capture the capability of a Thorpe Tube in providing precise flow metrics. Discrete volume measurement would imply a totalized or cumulative volume, which is not the function of a Thorpe Tube. Estimated flow rates suggest a less accurate approach, which stands in contrast to the true measurement capabilities of the Thorpe Tube. Similarly, a pressure-dependent flow rate indicates a measurement influenced by varying pressures, which is not applicable within the design and function of a Thorpe Tube.