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Air gap measurement


Inobalt's Expert Vibro devices are used to measure air gaps on generators.


Narrow distance sensors are installed at the stator. Measurement is non-contact. The rotor generates an equidistant signal for each rotor pole passage.


The sensor system is made up of an air gap sensor and a module for signal feed and conditioning. The air gap sensor is usually fixed to the stator. Measurement typically ranges from 1 ... 50 mm.


The Expert Vibro device records the time signal (distance) from each air gap sensor for each turn of the rotor. Synchronous triggering takes place via a digital rotation pulse.


Each rotor pole is portrayed with a negative signal level. The Expert Vibro device automatically determines the minimum air gap and a chronological pole position that can be converted into phase information in the 0 … 360° range. The data then enables a rotor profile to be portrayed (as polar coordinates).


The Expert Vibro device monitors the minimum air gap for critical values. The ProfiSignal software enables users to portray and evaluate the measurement data in trend diagrams.


Benefits of Inobalt products

 

  • Compact, inexpensive monitoring systems for measuring generator air gaps
  • Independently operating device with a 16 GB data logger capacity
  • Universal inputs suited to air gap sensors
  • Determination and monitoring of minimum values
  • Connectivity to control systems via PROFIBUS-DP or digital outputs