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Manufacturer
Model
What This Guide Helps With
Identifies inaccurate temperature or pressure readings causing cycle failures, alarms, or inconsistent sterilization performance due to sensor drift or external influences.
Step-by-Step Troubleshooting
Ensure Staff and Equipment Safety
- Confirm the sterilizer is not in an active cycle, depressurized, and cooled before inspection.
- Do not open the chamber under pressure.
Verify Reported Readings vs. Display
- Compare displayed temperature/pressure values with printed records or system logs.
- Look for inconsistencies or gradual deviation trends, which suggest drift rather than sudden failure.
Check for Active Alarms or Error Codes
- Review the control panel for sensor-related alarms.
- Document any codes, as they may indicate which sensor (temperature vs. pressure) is affected.
Inspect External Connections and Harnesses
- Check accessible sensor wiring and connectors for looseness, corrosion, or damage.
- A poor connection can mimic sensor drift by causing unstable readings.
Evaluate Steam Supply Stability
- Confirm facility steam supply is stable and within specification.
- Fluctuating steam pressure can appear as sensor drift but is actually a utility issue.
Check Chamber for Residue or Scale Buildup
- Inspect the chamber and exposed sensor areas (if visible) for mineral buildup or debris.
- Scale can insulate sensors and cause inaccurate readings.
Run a Test Cycle and Observe Behavior
- Run an empty cycle and monitor temperature/pressure rise and stability.
- Look for slow response, overshooting, or inability to maintain setpoint.
Compare with Independent Measurement (If Available)
- Use a calibrated external temperature/pressure test device if available.
- If readings differ significantly, this supports sensor drift or calibration issues.
Review Calibration Status
- Check maintenance records for last calibration date.
- If overdue or recently serviced, calibration drift is more likely.
Power Cycle the Unit
- Shut down and restart the sterilizer to rule out control system glitches affecting sensor readings.
- If readings normalize, monitor for recurrence.
Swap with Known Good Sensor (If Accessible and Approved)
- If your facility allows and access is external, swap with a known good sensor.
- If issue follows the sensor, it confirms drift/failure.
If the Problem Persists
If inaccurate readings continue after external checks, the issue is likely internal sensor degradation or calibration failure.
Remove the sterilizer from service, label it Out of Service, and send for repair or calibration verification.
Knowing when to stop prevents unnecessary risk and ensures proper sterilization performance.
Clinical Use Tip
Do not troubleshoot or validate sterilization performance on instruments intended for patient use.
Always remove the unit from clinical workflow and use a backup sterilizer.
Work Order Documentation (CCR Method)
CCR = Complaint, Cause, Resolution
Complaint
What was reported by the clinical staff.
Example:
"Sterilizer failing cycles with inconsistent temperature readings and pressure alarms."
Cause
What was observed during troubleshooting.
Example:
"Temperature sensor drift due to calibration deviation and minor scale buildup on sensor surface."
Resolution
What action was taken.
Example:
"Cleaned chamber, verified readings with external device, and removed unit from service for calibration."
Helpful Details to Include (If Known)
- Alarm messages or codes observed
- Temperature/pressure trends during cycle
- Calibration due date checked
- Steam supply verified stable
- Chamber condition (clean vs. scaled)
- External measurement comparison performed
- Final device status (removed from service or operational)
Final Thought
Sensor drift can be subtle but has major implications for sterilization effectiveness. Always start with external factors like steam quality and buildup before assuming failure. When readings cannot be trusted, removing the device from service is the correct decision. Proper documentation ensures traceability and supports safe return to service.
That is successful troubleshooting.