RPFT RPFT Equipment Calibration & Quality Control 1 — Questions and Answers
Question 1: How often should a 3-liter calibration syringe be used to verify spirometer volume accuracy?
- At least once daily before testing (Correct answer)
- Once per week
- Only when a new patient arrives
- Monthly by a certified technician
Correct answer: At least once daily before testing
ATS/ERS guidelines require volume calibration verification with a 3-liter syringe at least once each day testing is performed.
Question 2: What is the acceptable volume accuracy range for a spirometer calibration check using a 3-liter syringe?
- Within ±3.5% or 65 mL (Correct answer)
- Within ±5% or 100 mL
- Within ±10% or 200 mL
- Exactly 3.000 L with no tolerance
Correct answer: Within ±3.5% or 65 mL
ATS/ERS standards require the measured volume to be within ±3.5% of the known syringe volume (±105 mL for a 3-L syringe).
Question 3: Which biological control method is used to track long-term spirometer performance trends in a PFT lab?
- Testing a stable staff member and plotting control charts (Correct answer)
- Testing a calibration syringe at three different speeds
- Running manufacturer-supplied electronic test signals
- Comparing results across two different spirometers
Correct answer: Testing a stable staff member and plotting control charts
Biologic controls involve repeated testing of a healthy, stable staff member whose values are charted over time to detect equipment drift.
Question 4: What does a linearity check of a spirometer assess?
- Accuracy across the entire volume range, not just at 3 liters (Correct answer)
- The resistance of the mouthpiece filter
- The response time of the flow transducer
- Temperature compensation at different altitudes
Correct answer: Accuracy across the entire volume range, not just at 3 liters
Linearity testing verifies that the spirometer reads accurately at low, mid, and high volumes, ensuring consistent performance across the full range.
Question 5: When should a body plethysmograph undergo leak testing?
- Daily before patient testing (Correct answer)
- Only after a patient complaint
- Annually by the manufacturer
- Every six months
Correct answer: Daily before patient testing
Body plethysmograph leak checks should be performed daily, because even small leaks can significantly alter pressure measurements and falsify lung volume results.
Question 6: Which gas is used as the reference for the thermal conductivity detector in a helium dilution FRC measurement system?
- Helium (Correct answer)
- Nitrogen
- Oxygen
- Carbon dioxide
Correct answer: Helium
The thermal conductivity detector measures helium concentration because helium has a uniquely high thermal conductivity that is easily distinguished from other respiratory gases.
RPFT RPFT Equipment Calibration & Quality Control 1
How often should a 3-liter calibration syringe be used to verify spirometer volume accuracy?