CERTIFIED PULMONARY
FUNCTION
TECHNOLOGIST CPFT
PRACTICE EXAM
COMPLETE
Question 1: During daily spirometer calibration veri�cation, a 3-L syringe repeatedly reads 2.72 L. What should the technologist do before patient testing?
Choices:
1) Repeat the syringe injections and accept the mean if it is within 5% of 3 L 2) Apply a correction factor to patient volumes until the next scheduled service 3) Verify only with a biologic control and begin testing if that value is stable 4) Recalibrate or troubleshoot the spirometer and repeat veri�cation Correct Answer: Recalibrate or troubleshoot the spirometer and repeat veri�cation Explanation: A 2.72-L reading from a 3-L syringe represents excessive volume error. The system should be recalibrated or troubleshooting performed and calibration veri�cation repeated before patient testing.Page 1
Question 2: Which device is the primary reference tool used to verify volume
accuracy of a diagnostic spirometer?
Choices:
1) Precision rotameter 2) Calibrated water manometer 3) Flowmeter calibration analyzer 4) 3-L calibration syringe
Correct Answer: 3-L calibration syringe
Explanation: A calibrated 3-L syringe is the standard reference device used for spirometer volume calibration veri�cation.
Question 3: A pneumotach-based spirometer calculates exhaled volume by
integrating which measured variable over time?
Choices:
1) Di�erential pressure without conversion 2) Gas concentration 3) Flow 4) Temperature
Correct Answer: Flow
Explanation: A pneumotachograph measures air�ow from a pressure di�erence across a resistive element; volume is obtained by integrating �ow over time.Page 2
Question 4: A body plethysmograph is most directly based on which physical
principle?
Choices:
1) Dalton's law 2) Henry's law 3) Fick's law 4) Boyle's law
Correct Answer: Boyle's law
Explanation: Body plethysmography uses Boyle's law, which relates pressure and volume changes of a gas at essentially constant temperature.
Question 5: Which analyzer principle is commonly used for rapid measurement of
carbon monoxide during single-breath DLCO testing?
Choices:
1) Paramagnetic analysis 2) Electrochemical fuel-cell analysis 3) Thermal-conductivity analysis 4) Infrared absorption
Correct Answer: Infrared absorption
Explanation: Carbon monoxide strongly absorbs infrared energy, so infrared analyzers are commonly used for rapid CO measurement in DLCO systems.Page 3