Condition Monitoring

Condition Monitoring, as it applies to maintenance, is the process of monitoring the condition(s) of a machine based on information.  That information may be based on numerous sources, such as:

  • Performance-based measurements – speeds, feeds, quality, pressures, tonnage, and more. Any performance-based measurement is an indicator of the machine’s ability to produce.  These parameters are used to base the machine’s performance against its historical output, or against other, similar machines.
  • Condition-based measurements – vibration levels, current (amp) draw, component temperatures (such as bearings or gearboxes), thermal mapping, compressed air usage, flows, pressures, and so on. These parameters are compared against historical trends, and typical industrial benchmarks, to determine any impending problems, and to give early warning of needed repairs/replacement.
  • Inspection-based measurements– periodic visual inspection of the machine, by operations and maintenance, to check for any conditions such as loose bolts, coupling wear, broken welds, safety inspections, and so on.

As an example – a critical HVAC pump in a data center:

  • The control room operator may monitor flow (in gpm), pressure, overall vibration levels, and current draw. Any sudden changes in these would lead to further inspection.
  • Maintenance may collect vibration data from the motor and pump bearings, to examine critical frequency-based vibration signatures. A periodic infrared inspection of the power distribution may be done to inspect electrical joints, terminations, and insulation breakdown.  If the pump is oil lubricated, an oil analysis may be done, to determine seal quality/leakage, and specific component wear, such as metals in the oil.  Any changes in these parameters might lead to a work order, to perform maintenance.
  • Water treatment testing may be done, to determine proper cleanliness/filter quality, chemical additives, bacterial controls in the water, de-foaming agents, and so on.

All of these parameters give an indication of the “condition” of the machine, and give operations and maintenance the ability to determine of this machine is performing its intended function, and if maintenance is required.

 

Related blog posts:

What about the other 75-80% of your rotating machinery?

The Three T’s

Maintenance Strategies: Part Two

Maintenance Strategies, Part Three – Predictive Maintenance

Maintenance Strategies: Part Four – Proactive Maintenance