Equipment and System Fundamentals
The Equipment and System Fundamentals domain tests how screening equipment works, how it fails, and how to tell calibration, verification, maintenance, and self-test apart. Marks are lost when candidates treat a green light as proof of performance.
Core distinctions
- Calibration is a documented comparison with a traceable standard, with adjustment where needed.
- Verification confirms that equipment still meets performance requirements; it does not adjust the equipment.
- Maintenance is servicing or replacement; it may restore performance but is not a calibration record.
- A self-test covers limited functions and does not prove detection or measurement performance.
Failure modes and configuration
Know the common failure modes: drift, reduced sensitivity, false alarms, electrical noise, environmental effects, blocked apertures, and software faults. Firmware and configuration settings should be version-controlled and locked where possible. Changes to settings, including sensitivity, need authorization and a record.
Worked example
An X-ray unit alarms intermittently on an empty tray. The tempting fix is to lower sensitivity. That hides a possible fault and weakens detection. Instead, check power and grounding, warm-up, calibration status, nearby interference, and recent maintenance; then log the fault and escalate. Treat a nuisance alarm as a possible equipment fault until proven otherwise.
Traps
- Equating a passed self-test with calibration.
- Turning down sensitivity to silence alarms.
- Loading unsupported firmware.
- Ignoring temperature, humidity, or power specifications.
- Clearing fault logs before investigation.
- Assuming a backup power supply maintains all functions.