On this page
Asset Type
Manufacturer
Model
What This Guide Helps With
This guide assists Clinical Engineering in troubleshooting a Drager Primus ventilator displaying a flow sensor calibration fault. Flow sensor calibration faults prevent accurate measurement of patient tidal volume and airflow, potentially compromising ventilation accuracy. Most causes can be external or easily verified before assuming internal sensor failure.
Step-by-Step Troubleshooting
Verify Power and Startup
- Ensure the ventilator is plugged into a verified working outlet.
- Power cycle the device.
- Why: Temporary electronic glitches can sometimes clear with a restart.
Inspect Breathing Circuit Connections
- Confirm that all inspiratory and expiratory hoses are properly connected and seated.
- Check for leaks, kinks, or obstructions in the tubing.
- Why: Misconnected or obstructed tubing can falsely trigger flow sensor errors.
Check Flow Sensor and Adapter
- Remove the flow sensor module and inspect for visible damage, moisture, or debris.
- Re-seat it firmly into its connector.
- Why: Poor seating or contamination can prevent proper calibration.
Run a Device Self-Test
- Perform the ventilator’s pre-use check or system self-test.
- Observe if the fault persists.
- Why: Confirms whether the problem is persistent or intermittent.
Inspect Gas Supply and Filters
- Ensure oxygen, air, and other gases are within acceptable pressure ranges.
- Check any inline filters for blockage or contamination.
- Why: Abnormal gas flow can interfere with flow sensor calibration.
Swap Flow Sensor Module (if available)
- Replace the flow sensor with a known good module.
- Repeat self-test.
- Why: Confirms whether the fault is sensor-specific or system-wide.
If the Problem Persists
Common external causes have been ruled out.
The ventilator should be:
- Removed from service
- Labeled Out of Service
- Sent for repair or bench evaluation by qualified service personnel
Note: Knowing when to escalate is proper troubleshooting.
Clinical Use Tip
Do not attempt to ventilate a patient on a device with a flow sensor calibration fault.
Move the patient to a verified functioning ventilator first.
Troubleshoot only when patient safety is ensured.
Work Order Documentation (CCR Method)
CCR = Complaint, Cause, Resolution
Complaint
What was reported by the clinical staff.
Example:
“Ventilator displays “Flow Sensor Calibration Fault” during pre-use check.”
Cause
What was observed during troubleshooting.
Example:
“Flow sensor module either misaligned or failed calibration; initial inspection of connections and tubing showed no leaks or obstruction.”
Resolution
What action was taken.
Example:
“Flow sensor module replaced with verified working module; device retested successfully. If fault persisted, ventilator sent to service bench.”
Helpful Details to Include
- Outlet verified with test device
- Tubing and circuit connections inspected
- Sensor module condition noted (clean, dry, undamaged)
- Gas supply pressures checked
- Self-test results recorded
Final Thought
Proper troubleshooting of flow sensor faults relies on systematically checking external and easily verifiable causes first, prioritizing patient safety, and escalating when necessary. Clear CCR documentation supports accountability and future reference.
That is successful troubleshooting.