Inspection, testing, and fault diagnosis

Inspection, testing, and fault diagnosis

Inspection Techniques

  • Inspection techniques are used to detect faults and potential problems in mechanical systems or equipment.
  • Visual inspection is the simplest form: look for visible signs of damage such as wear, corrosion, fractures or leaks.
  • Aural inspection involves listening for irregular noises which could indicate a problem.
  • Tactile inspection involves using touch to locate unusual vibrations or heat.
  • Sensory inspection techniques, combining visual, aural, and tactile inspection, are often first-line checks.
  • Non-destructive testing (NDT) techniques include magnetic particle inspection and dye penetrant inspection.
  • Borescope inspection can be used to examine difficult-to-reach or internal areas of equipment.
  • Pressure testing checks the integrity of pressure systems to ensure they are safe to use.

Testing Techniques

  • Functional testing includes running systems or equipment to confirm they operate as required. If not, the characteristic faults help identify problem areas.
  • Testing equipment should be used where required, such as multimeters for electrical systems and tachometers for rotational speed.
  • Performance testing checks the system’s ability to perform its intended function under varying conditions.
  • Stress testing checks the system’s ability to function under heavy load situations, such as high temperatures or high pressure.
  • Endurance tests check how long a system can operate continuously without failure.
  • Testing should be performed following the manufacturer’s guidelines to ensure reliable, accurate, and safe results.

Fault Diagnosis

  • Fault diagnosis is the process of identifying the cause of any faults in a system or piece of equipment.
  • A structured approach, often known as root cause analysis, is usually taken, including defining the problem, identifying potential causes, testing hypotheses, and deciding on the most probable cause.
  • To diagnose a fault, it may be necessary to refer to technical manuals or diagrams, or to consult with colleagues or manufacturers.
  • Fault trees can be constructed as a method of visualising the potential causes of a system failure and how they may be related.
  • Basic principles of mechanics, such as the relationship between force, motion and energy, are always important when diagnosing problems.
  • Data logging and documentation of faults and their resolution are important for future reference and prevention of recurring faults.