Condition Monitoring Guide: Technologies & Implementation

What is Condition Monitoring?

Condition monitoring is the process of monitoring a parameter of equipment condition (vibration, temperature, oil quality, etc.) over time to detect changes that indicate a developing fault. The goal is to identify deterioration early enough to plan maintenance before failure — but late enough that you're not doing unnecessary maintenance.

The Five Core Technologies

• 1. Vibration monitoring: The most widely used technology for rotating equipment. Every mechanical fault produces a characteristic vibration signature. Portable data collectors are used for route-based monitoring; permanently installed sensors for continuous monitoring. Best for: pumps, motors, fans, gearboxes, compressors, turbines.
• 2. Oil analysis: Laboratory analysis of lubricating oil reveals wear metals (iron, copper, tin, lead), contaminants (water, dirt, fuel), and lubricant degradation (viscosity, oxidation). Best for: gearboxes, engines, hydraulic systems, large oil-bath bearings.
• 3. Thermography (infrared): An IR camera detects surface temperature anomalies. Hot spots indicate electrical faults (loose connections, overloaded circuits), mechanical faults (bearing overheating, friction), and process issues (steam leaks, blocked pipes, insulation failures). Best for: electrical switchboards, bearings, steam traps, refractory.
• 4. Ultrasonics: Detects high-frequency sound (ultrasound) emitted by friction, turbulent flow, and electrical discharge. Used for bearing monitoring (early stage, before vibration detects it), compressed air leak detection, steam trap testing, and partial discharge in electrical equipment. Best for: bearings, steam traps, compressed air systems, electrical switchgear.
• 5. Performance monitoring: Tracking operating parameters (flow, pressure, temperature, power, efficiency) over time. A decline in performance indicates degradation — fouling, wear, or internal damage. Best for: heat exchangers, pumps, compressors, boilers, cooling towers.

Choosing the Right Technology

Route-Based vs Continuous Monitoring

• Route-based (portable): A technician walks a predetermined route with a portable data collector, taking readings at each measurement point. Data is uploaded to analysis software. Lower cost, but only captures a snapshot — faults that develop between routes are missed.
• Continuous (permanent): Sensors are permanently installed and transmit data continuously to a monitoring system. Higher cost, but captures all data — including transient events and rapid deterioration. Essential for critical equipment where early detection is vital.

Setting Alarm Levels

1. Baseline: Collect 30+ readings over several weeks of normal operation.
2. Alert: Set at baseline mean + 2× standard deviation (95% confidence). Investigate but don't shut down.
3. Alarm: Set at baseline mean + 3× standard deviation (99.7% confidence) OR the relevant ISO standard limit — whichever is lower.
4. Danger/Trip: Set at ISO standard 'Unacceptable' level. Equipment should be shut down.
5. Rate-of-change alarm: Triggers if the reading increases by more than 25% in 24 hours — catches rapid degradation.