Condition Monitoring: Sensors Used for Electro-Elements in Space Probes

[bill nye scienceguy!]

what kind of sensors do EEs use for condition monitoring in the electro- elements of an electromechanical system? with a view to the subsystems inside a space probe.

 

[verafloyd]

Do encoders count as sensors? I mean those that are used for counting the number of rotation of a motor. There are also torque-meters, tachometers, pressure sensors, etc. In some situations they can even use a variable capacitor or a rheosta for those purposes.

 

[smn]

By condition monitoring are you referring to vibration & speed monitoring?

We measure various vibrations along gas / steam turbines. We have what we call a relative shaft probe (commonly known as a stinger) which is basically a proximity probe. The probes are gapped electrically to the mid-point operating range of the probe with the shaft jacked so that the probe can measure the gap sufficiently either side of this mid-point (if that makes sense!).
We also use what is known as an absolute measuremnent and the transducer for this is installed on top of the stinger and measures the absolute vibration by the use of an accelerometer (plenty of info on this on google search).
The speed of the machines are measured using speed probes which are 'focused' on a toothed wheel which provides digital pulses to the electronics which determines the speed of the shaft, again, loads of info available on this.
For surge detection and thrust / pad wear monitoring, proximity probes are again used.

This is a VERY basic description. A good place to learn more is on a companies website called SKF.

Hope this helps :)