In a continuous-flow oxygen system, what controls the amount of oxygen delivered to a mask?

In a continuous-flow oxygen system, the correct mechanism for controlling the amount of oxygen delivered to a mask is through a calibrated orifice. A calibrated orifice allows for a precise flow rate of oxygen to be maintained, ensuring that the correct amount of oxygen is delivered to the user based on the pressure and flow characteristics of the system. The design of the orifice is such that it determines how much gas can pass through it at a given pressure, thus directly influencing the flow of oxygen to the mask. This is vital in ensuring that the user receives a consistent and adequate supply of oxygen, which is crucial for maintaining proper physiological function, especially in environments where supplemental oxygen may be necessary.

While options like calibrated valves, electronic sensors, and manual adjustments could play roles in other systems, they do not provide the same level of precise control over oxygen flow in a continuous-flow system as a calibrated orifice does. A calibrated valve might help adjust flow but isn’t the primary means in this specific type of oxygen delivery system. Electronic sensors could monitor flow rates but typically do not directly control the flow. Manual adjustments may be necessary in some instances, but they lack the precision and automated function provided by the calibrated orifice in delivering oxygen consistently.