Blog | Sensonics

4 Ways to Integrate Vibration Monitoring with Legacy Systems

Written by sensonics | Jan 26, 2026 10:00:00 AM

Legacy turbine supervisory systems, although often still mechanically sound and robust, frequently lack the advanced monitoring capabilities required to ensure optimum performance, reliability, and safety in modern production and power-generation environments. A cost-effective approach is to integrate upgraded, next-generation monitoring technologies into your legacy turbine setup. This article explores several strategies for enhancing older turbine infrastructure with modern turbine supervisory, vibration monitoring, and seismic monitoring systems.

1. Invest in an API 670-compliant system for enhanced protection

Many legacy turbines—particularly in the power-generation sector—operate under high pressures and elevated mechanical stress, resulting in an increased risk of critical failures. Retrofitting your system with an API 670-compliant monitoring solution, such as the Sentry G3 from Sensonics, provides advanced speed monitoring, vibration analysis, and improved protection against potential faults. This integration also ensures access to accurate, high-resolution performance data so that safety thresholds can be effectively maintained.

Ageing Electronic Components in Legacy Protection Systems

Older supervisory and monitoring units often suffer reduced reliability due to ageing electronic components—most notably aluminium electrolytic capacitors, which are among the most common points of failure.

Why aluminium electrolytic capacitors fail:

  • Electrolyte evaporation:
    These capacitors contain a liquid electrolyte that naturally evaporates over time through the component seal. Heat and ripple currents accelerate this process, gradually reducing capacitance and stability.
  • Chemical degradation:
    Over many years, the electrolyte can break down chemically, losing its effectiveness and its ability to repair the internal dielectric layer.
  • Manufacturing defects (“capacitor plague”, 1999–2007):
    Faulty electrolyte formulas caused widespread premature failures—often visible as swelling, bulging, or leakage.

Impact on legacy monitoring systems:

Failures in power-supply or filtering capacitors can lead to:

  • increased voltage ripple
  • unstable operation
  • signal noise or drift
  • intermittent or total system failure

While ceramic and film capacitors typically age more slowly, electrolytic capacitors have a finite lifespan and usually require proactive replacement to maintain long-term reliability. Other components—such as resistors, diodes, and transistors—can also degrade over time, though their ageing failure rate is generally much lower.

How you benefit (system upgrade):

  1. Reliable machine protection for your most critical assets
  2. Early fault detection to support planned maintenance and minimise downtime
  3. Compliance with internationally recognised industry safety standards

2. Non-contact vibration and position monitoring

Older turbines may lack integrated mounting points for modern sensors, making direct retrofits more complex. While casing-mounted vibration sensors can often be installed via drill/tap/spot-face methods—or with welded/screwed mounting pads—non-contact sensors such as eddy-current proximity probes can be significantly more demanding to install if suitable mounting provisions do not already exist.

Proximity probe installations may require:

  • machining through-holes in the casing for probe holders (space- and access-permitting), or
  • installing internal probe bracketry—ranging from simple to complex—secured via wire-locked screws, tab-locked fixings, or welding.

For this reason, retrofits often aim to match existing probe thread sizes and lengths when replacing older systems to avoid intrusive casing modifications.

Capacitive air-gap sensors, on the other hand:

  • are always glued to the stator
  • can typically be installed with the rotor in place

This makes them a practical option in situations where shaft-relative measurement is not required.

How you benefit:

  1. Reduced mechanical intrusion compared to on-casing retrofits
  2. Improved precision and accuracy through high-quality non-contact measurement
  3. Real-time feedback on turbine behaviour under varying load conditions

3. Scalable condition monitoring solutions

Modern monitoring platforms enable a scalable approach to turbine protection. Systems such as Sensonics’ SentryCMS allow operators to begin with a minimal set of vibration, temperature, or overspeed channels and progressively expand coverage as operational needs evolve.

In addition to these core measurements, modern systems support more advanced supervisory parameters such as:

  • Relative Shaft Vibration
  • Shaft Eccentricity
  • Thermal Expansion (casing or differential)

These metrics are essential for understanding rotor behaviour, thermal growth, and long-term machine alignment.

How you benefit:

  1. Reduced reliance on major system overhauls by expanding only when needed
  2. A centralised dashboard that streamlines maintenance and improves collaboration across onshore and offshore teams
  3. Access to historical trend data, enabling accurate predictive maintenance planning and downtime scheduling

4. Modular turbine supervisory instrumentation

A modular turbine supervisory system—such as the Sentry G3—is an effective upgrade path for legacy turbines that lack modern displacement, speed, and vibration monitoring capabilities. Modular architectures allow channel-by-channel expansion and configuration, enabling operators to update instrumentation progressively without wholesale replacement.

This flexibility is particularly valuable in industries such as mineral extraction and metal processing, where turbines operate under heavy and variable loads.

How you benefit:

  1. Scalable monitoring capabilities that grow alongside operational requirements
  2. Customisable configurations tailored to specific turbine designs and operating contexts
  3. Extended turbine lifespan by modernising protection and monitoring in controlled phases

Find out more

Get in touch with Sensonics today to learn more about our advanced turbine supervisory systems and support services.

​Image source: Canva