On this page
Asset Type
Manufacturer
Model
What This Guide Helps With
Identifies external causes of flow sensor calibration errors such as contamination, incorrect setup, environmental factors, or accessory issues affecting accuracy.
Step-by-Step Troubleshooting
Ensure Patient Safety First
- Confirm the device is not actively in use on a patient.
- Move testing to another spirometer if needed.
Expected Outcome:
Safe environment for troubleshooting without affecting patient care.
Verify Calibration Prompt and Error Message
- Review the exact calibration error message on the screen.
- Attempt calibration again to confirm repeatability.
Expected Outcome:
Consistent error confirms a true calibration issue rather than user interruption.
Why:
Helps distinguish between workflow interruption and actual sensor or setup problem.
Check Flow Sensor Installation
- Remove and reseat the flow sensor.
- Ensure proper orientation.
- Ensure fully seated connection.
- Check for any looseness.
Expected Outcome:
Device recognizes the sensor and allows calibration.
Why:
Improper seating is a common cause of calibration failure.
Inspect Flow Sensor for Contamination or Moisture
- Check for condensation inside the sensor.
- Look for debris, mucus, or residue.
- Inspect for visible damage.
- If contaminated, replace with a clean or new sensor.
Expected Outcome:
Clean sensor allows successful calibration.
Why:
Obstruction or moisture alters airflow measurement accuracy.
Verify Correct Sensor Type and Accessories
- Confirm the correct flow sensor is being used for the system.
- Ensure compatible mouthpiece and filters are installed.
Expected Outcome:
Proper accessories restore accurate calibration.
Why:
Incorrect components can cause inaccurate airflow readings.
Check Calibration Syringe (if used)
- Ensure correct volume syringe (typically 3L).
- Verify no leaks or sticking plunger.
- Use smooth, full strokes during calibration.
Expected Outcome:
Calibration completes successfully with consistent readings.
Why:
Faulty calibration equipment leads to false calibration errors.
Evaluate Environmental Conditions
- Check for extreme temperature changes.
- Check for high humidity.
- Ensure no strong airflow (vents or fans nearby).
Expected Outcome:
Stable environment allows accurate calibration.
Why:
Spirometry is sensitive to environmental conditions affecting airflow measurement.
Restart the Device
- Power cycle the unit and allow full system initialization.
- Retry calibration after restart.
Expected Outcome:
Temporary software or communication issues are cleared.
Try Alternate Flow Sensor (if available)
- Replace with a known good sensor.
- Attempt calibration again.
Expected Outcome:
Successful calibration confirms original sensor failure.
If the Problem Persists
If calibration continues to fail after verifying sensors, accessories, environment, and calibration tools, internal sensor electronics or processing may be at fault.
Remove the device from service, label it Out of Service, and send for repair or bench evaluation.
Knowing when to stop prevents unnecessary downtime and ensures accurate patient testing.
Clinical Use Tip
Never attempt calibration or troubleshooting during active patient testing. Move the patient to a backup device first and ensure therapy continuity. Always verify calibration before patient use to prevent inaccurate pulmonary results.
Work Order Documentation (CCR Method)
CCR = Complaint, Cause, Resolution
Complaint
What was reported by the clinical staff.
Example:
"Unit failed flow sensor calibration during daily spirometry setup."
Cause
What was observed during troubleshooting.
Example:
"Contaminated flow sensor with moisture affecting airflow measurement."
Resolution
What action was taken.
Example:
"Replaced flow sensor and successfully completed calibration."
Helpful Details to Include (If Known)
- Alarm or error message behavior
- Accessories swapped (flow sensor, mouthpiece, filters)
- Calibration syringe performance
- Environmental conditions
- Power cycle performed
- Final calibration status
Final Thought
Accurate spirometry depends heavily on proper calibration and clean sensors. Always start with simple external causes like contamination or setup before suspecting internal failure. Patient safety and test accuracy must remain the priority, and clear documentation ensures traceability and confidence in results.
That is successful troubleshooting.