RPFT Equipment Calibration & Quality Control Flashcards

Which leak test method is most commonly used to verify the integrity of a body plethysmograph cabinet?

Answer: Sealing the cabinet and monitoring pressure drift over time

A timed pressure-decay (leak) test with the cabinet sealed detects leaks that would disrupt the constant-volume assumption required for accurate plethysmographic measurements.

What is the role of a HEPA filter placed on the exhalation port of a spirometer during patient testing?

Answer: Protects the flow sensor from contamination and reduces cross-infection risk

HEPA or bacterial/viral filters protect the spirometer internals from patient secretions and prevent cross-contamination between patients.

A spirometer's volume reading drifts upward by 4.2% over two weeks of biologic controls. What should the technologist do?

Answer: Take the spirometer out of service and recalibrate or service it

A consistent upward drift exceeding the ±3.5% ATS accuracy limit indicates equipment malfunction requiring removal from service and correction.

What information should be documented in the PFT lab's equipment logbook after each daily calibration?

Answer: Date, time, technologist ID, calibration values, pass/fail status, and any corrective actions

Comprehensive calibration records including operator, values, and any corrective actions support quality assurance audits and regulatory compliance.

Which parameter is checked during a resistance test of a pneumotachograph flow sensor?

Answer: Pressure drop across the sensor at a known flow rate

Pneumotachograph sensors measure flow by detecting the pressure differential across a resistance mesh; verifying pressure drop at a known flow confirms proper sensor function.

When must a spirometer's calibration be repeated within the same testing day?

Answer: After any significant temperature change in the testing room

Significant ambient temperature changes alter gas viscosity and sensor characteristics, requiring recalibration to maintain BTPS accuracy.