Anisotropic Magneto Resistive - The future of fuel and fluid level detection

A major milestone occurred in 2011 -  the first commercially successful application of Anisotropic Magneto Resistive (AMR) technology applied to fuel level sending.    

We made our technological introduction a critical test for the sending unit as we choose to apply this sender to the most popular GA aircraft built.  It was a gutsy move to use aviation as our launch vehicle, but by all measure and after two years of flawless performance, we can say that this methodology for measuring fuel level has been overwhelming success.

The CiES Fuel Level Sensor is a magnetic, non-contacting angular position sensor that converts rotary motion of the float arm into an electrical signal.
This signal provides an accurate fuel level measurement and enables reliable Multi-Function Display or Fuel Gauge readout.  

Our compact, modular design utilizing the familiar SAE 5 bolt mounting allows a wide range of applications and our calibrated output signal compensates for component and assembly variations.  Our unique design using our patented AMR technology enables dependable performance and durability.


The CiES Fuel Level Sensor's linear output - either Frequency, Voltage or PWM Current Mode  is directly proportional  to the position of the float in the tank.  The we derive this location by the measurement of the magnetic field direction.  This method  allows for wide mechanical tolerances and sensor placement.  Just like a compass in your hand - no matter where or how you move the compass, it will continue to point North - our sensor continues to point at the float.

Noncontact performance is made possible by state-of-the-art  programmable Anisotropic Magneto Resistive (AMR) technologies. Rotating magnets generate a voltage with a paired sine wave response signal.   The sensor operates in a combined linear region of this  sine wave response signal.

Benefits 

• Low cost with electrical interface that powers and reads AMR effect output signal
• Modular and common interface help achieve competitive cost
• Can be easily modified to meet specific customer requirements
• Protection against contamination and fuel exposure
• Lower drive current minimizes system power consumption
• High resolution output signal with low hysteresis for improved system performance

Typical Applications 

The CiES Fuel Level Sensor is ideally suited for a wide range of aviation, automotive, heavy equipment, commercial vehicle, rail in-tank applications for Gasoline, Avgas, Jet A, Propane, Alcohol & Flex Fuel blends.  The non contact measurement method is immune from attack from any sulfur based, water based or solid contaminates.  This method of fuel measurement allows for a single fuel sender  to be applied to a wide variety of fuel types, including different fuels utilized in the same tank, providing the identical output response.

Performance Advantages

The CiES Fuel Level Sensor features a proven technology that has been used in high volume absolute position sensor applications, like brake by wire, throttle and accelerator positioning, for more than 10 years.

The non-contacting design of the sensor maximizes product life by eliminating fuel level signal deterioration due to contact wear, resistive ink failure or dendritic growth.  Our low current draw with high resolution output signal may be calibrated for the angular travel of a specific application and allows us to  compensate for any assembly or tank variations.  

Fuel Level Senders - Automotive

Fuel level sending has been the providence of electrical resistance since somewhere in the 1930's when electrification of the automobile hit full stride.  The Ford Model A used a very clever sight gauge so that you actually saw a liquid representation of fuel level - neat design but expensive.

http://www.facebook.com/Fuellevel

Resistance Level worked very well and was easy to understand  -  X Ohms Full - Y Ohms Empty

Simple

And then suddenly somebody decided to add alcohol -  to fuel -

Methanol and ethanol contain soluble and insoluble contaminants.[5] Halide ions, which are soluble contaminants, such as chloride ions, have a large effect on the corrosively of alcohol fuels. Halide ions increase corrosion in two ways: they chemically attack passivating oxide films on several metals causing pitting corrosion, and they increase the conductivity of the fuel. Increased electrical conductivity promotes electrical, galvanic and ordinary corrosion in the fuel system. Soluble contaminants such as aluminum hydroxide, itself a product of corrosion by halide ions, clogs the fuel system over time. To prevent corrosion the fuel system must be made of suitable materials, electrical wires must be properly insulated and the fuel level sensor must be of pulse and hold type (or similar). In addition, high quality alcohol should have a low concentration of contaminants and have a suitable corrosion inhibitor added.

So if you turn to any car chat blog (ANY CAR CHAT BLOG)  -

Failed fuel level sensors are driving OBD II cars to the shoulder.

So we need to find a replacement  Smiths (Stewart Warner, VDO, Veglia, Et al) in a Pulse and Hold fuel senders - Not compatible 

We are producing  a patented new non-contact fuel level sensor.

We are applying the sensor presently  to aviation (aircraft, rotorcraft) - In aviation we don't have alcohol,  but we can't put wires in the tank - something about electricity and fuel

Aviation  requires - what cars - all cars using Alcohol mixed fuel need - A non contact fuel level sensor

It is also helpful in this environment 

Fuel Level Sensor Under Test

We use a new concept in our sender called Magnetoresistance - certain materials change resistance in the presence of a rotating magnetic field and they can do this from as far as 3/8" away actually from the dry side of the tank.

Most of us see this everyday in the compass on our smartphone

There is no pivot or contact resistance,  so the float can be smaller and the range can be larger (fuller fulls and emptier empties)

Neat thing is that the  output of this sensor  can mimic a resistive sensor

Hey if you find this interesting let us know

scott.philiben@ciescorp.com