Non-Invasive Inspections: A Review on Methods and Tools

Area of Science:

• Industrial Maintenance
• Condition Monitoring
• Machine Health Diagnosis

Background:

• Non-Invasive Inspection (NII) is crucial for modern industrial maintenance.
• NII enhances asset awareness, reducing costs, risks, and environmental impact.
• Existing literature lacks a formal definition for NII.

Purpose of the Study:

• Identify suitable NII sensing techniques for machine health diagnosis.
• Detect shaft misalignment and gearbox tooth damage in various machines.
• Evaluate NII methods for machines in hostile environments.

Main Methods:

• Literature review of sensing tools and techniques for NII.
• Categorization of NII methods into contact-based and non-contact-based.
• Critical review of vibration, AC voltage, flux, laser, imaging, acoustic, thermographic, and radar sensors.

Main Results:

• NII tools were categorized into contact-based (e.g., vibration) and non-contact-based (e.g., radar).
• Each technique has limitations; effectiveness depends on machine requirements and maintenance needs.
• Radar sensing demonstrates high potential for asset monitoring but requires further research.

Conclusions:

• No single NII technique is optimal for all machine health diagnostics.
• Selecting the right NII method requires considering specific machine operational and maintenance needs.
• Radar sensing offers promising features for NII machine health diagnosis, warranting further investigation.