Speed probes for aerospace monitoring

Speed sensors measure the speed, direction or position of the rotating engine shaft.

Accurate and reliable speed measurements under extreme temperature and vibration conditions. Meggitt’s magnetic speed probe designs are trusted by engine OEMS around the world.

Mounted on the engine or gearbox, each sensor is designed and qualified to suit the application. Over 60 designs are in service across a number of different applications with a typical mean time between failure (MTBF) of greater than 650,000 flight hours.

Meggitt’s engineering and research teams are pushing material science to the limit and are continuing to explore new high temperature materials for gas turbine engines. The team at MSS Basingstoke was part of the EU-funded research project called STARGATE (sensors towards advanced control and monitoring of gas turbine engines) that investigated a range of novel sensing techniques for gas turbines.

Features and benefits

  • High reliability, maintenance free
    Hermetically sealed construction with no moving parts so wear is eliminated
    Not affected by contaminants, including oil and dust

  • Operate in extreme temperatures, -150°C to +520°C (-238°F to 968°F)
    Units can be mounted in locations throughout the engine
    Stainless steel, titanium, or Inconel 600 housing

  • Ideal for engine environments
    Units can tolerate vibration levels up to 40g over a broad range of frequencies

  • Built-in redundancy
    Multiple channel design
    Channels can be electromagnetically isolated

  • No power supply required
    Inductance speed sensors use the movement of the rotating wheel to induce a voltage in the sensor. No supply voltage is required

  • Customised designs
    High output designs with single and multiple channel/pole configurations
    Probe is designed to meet the customer specification and fit within specified space envelope

Applications for Vibro-Meter® speed sensors

Our speed sensors are used in the following applications:

They measure the following:

  • Shaft rotational position
  • Direction of rotation
  • Shaft torque
  • Rotor revolution
  • Gas turbine shaft speed

How does a speed probe work?

A speed probe is an alternating voltage generator producing an electrical signal. The frequency of this electrical signal is proportional to the engine shaft speed. A speed probe contains one or two coils and a rare earth permanent magnet.

In rotating machinery the speed probe sensing surface faces the phonic wheel. As the magnetic flux varies in density with the passage of each tooth, these changes induce an alternating voltage in the coil surrounding the permanent magnet, the frequency of which is a function of shaft speed.

At Meggitt, we can provide you with a sensing and monitoring solution that is specific to your aerospace application and can be further customised to your particular requirements. To discuss what you need in more detail, contact us.