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Monday, June 18, 2012

Sensors Expo - Aircraft Fuel Level

Sensors Expo 

Cirrus Aircraft and CIES Inc made a joint presentation at the Sensors Expo Conference in Chicago the first week in June.

Topic of discussion was

- Applying our AMR Fuel Level Technology to an Application
  • Fuel Level and Ice Protection Fluid Sender in an Aircraft Application
    • Integration to Aircraft Avionics / Instrumentation 
    • Implications for reliable redundant fuel level - Fuel Qty and Fuel Flow     
    • Better Annunciation 
      • Fuel Imbalance Annunciation - proper left to right trim single engine aircraft
      • Low Fuel or IFR Reserve Warning 
    • Automatic fuel management - switching between tanks 

Discussed why a float based sensor is ideal for this application 
  • Shallow Tank 
  • Lots of fluid motion - constant motion 
  • Solid State Technology 
  • Intrinsically Safe - Explosion Proof 
Illustrated the advantages of AMR for this application - with a video 
  • We hold the patent - so no licensing 
  • Tolerant of angular and displacement alignment - position immune 
  • No appreciable temperature effect - critical for aircraft 
  • No hysteresis effect  
  • Issues with existing systems 



Illustrated the studies on the aircraft to achieve an accurate level for each aircraft produced 
  • Number of calibration points to reduce tank indication errors  
  • 5 was chosen - 
    • 0 Gallons - FAA regulations 
    • 5 Gallons - provide excellent accuracy at the bottom of the tank
    • 30 Gallons - At the aircraft TABS - Internal tank visual  reference 
    • 40 Gallons - reduce error at transition between inbd and outbd sensors 
    • 46 Gallons - Full 
  • The fuel quantity indication less than 1/2 gallon or 1% in potential error throughout the fuel level range.


In looking at this fuel level indication performance and evaluating the system in its application over time
  • Improved annunciation 
    • Low Fuel Annunciation 
    • Low Fuel Caution 
    • Low Fuel Warning 
    • Fuel Imbalance Caution 
    • Fuel Level Sensor - Failure 
  • The fuel quantity indication can be compared to the fuel totalizer and if in agreement 
    • Automatic switching of fuel from left to right tank 
    • If not - revert to manual actuation .