Smart fluid measurement using TDR technology

Single sensor accurately measures fluid and water levels.

Improved accuracy and reduced costs

Over 10,000 TDR fluid probes are flying on a range of aircraft platforms. Meggitt’s breakthrough fluid gauging system utilises high-speed electronics and RF-based technology to accurately measure fluid levels and is compatible with all fluid types.

Key benefits

  • Not affected by fluid contaminants
  • No calibration required on-aircraft
  • Built–in-test(BIT) diagnostics with fast and easy fault isolation
  • Up to 30% lighter than capacitance-type probes

Key features

  • Accurate to 2.5 mm (0.1”)
  • Compatible with all aerospace fluids without compensation
  • Interfaces with all aircraft communication systems
  • No length limitation
  • Multiple sensors can be connected to remote processor or electronics integral to the probe


Applications for TDR fluid level sensors

This technology has been selected for the following:

  • Helicopter fuel systems
  • Helicopter gearbox systems
  • Civil aircraft hydraulic systems

The length, number and positioning of the sensors and signal conditioners can be adapted to the needs of your application. We can also design curved and angular configurations that can be mounted in any orientation to accommodate the tank geometry.

How does a TDR fluid sensor work?

In its simplest form, the TDR system is comprised of a simple wave guide sensor and an electronic controller.

The system sends an RF pulse into the fluid which is reflected off the fluid (oil/air, fuel/air or fuel/water) interfaces. The system detects and measures the time between the returned reflection(s) (also known as “electronic echoes”) from each interface in order to determine the height and quantity of each fluid within the sensor.

At Meggitt, we can provide you with a fluid sensor 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.

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