Which device measures tidal volume in the breathing system?

Which device measures tidal volume in the breathing system?

• A. Ventilator
• B. Respirometer
• C. Capnograph
• D. Oximeter

Answer: (B)

Tidal volume is the amount of air moved in or out with each breath, so the device that directly measures this in the breathing circuit is the respirometer. It tracks the volume of gas displaced per breath, giving a real readout of how much air is delivered to the patient each cycle. This measurement is essential to verify adequate ventilation and to detect leaks or obstruction in the circuit. A capnograph measures CO2 concentration, not volume; an oximeter measures oxygen saturation; and while a ventilator displays delivered tidal volume, the dedicated instrument in the breathing system that measures the actual volume per breath is the respirometer.

Tidal volume is the amount of air moved in or out with each breath, so the device that directly measures this in the breathing circuit is the respirometer. It tracks the volume of gas displaced per breath, giving a real readout of how much air is delivered to the patient each cycle. This measurement is essential to verify adequate ventilation and to detect leaks or obstruction in the circuit. A capnograph measures CO2 concentration, not volume; an oximeter measures oxygen saturation; and while a ventilator displays delivered tidal volume, the dedicated instrument in the breathing system that measures the actual volume per breath is the respirometer.