The Fluid-Trac® 3-wire ultrasonic level sensor is a non-contact liquid level sensor that offers a wide variety of input and output options which enables it to interface with many different microprocessor-controlled fuel gauges or digital instrumentation.
The Fluid-Trac® 3-wire level sensor can be factory programmed to have a ratio-metric output to drive 12V fuel electronic gauges (automotive applications).
The Fluid-Trac® 3-wire level sensor can also be factory programmed to provide a non-ratiometric voltage output (0.5 to 4.5 V) for interfacing to control modules, PLC controllers, digital instrumentation, or DAQ systems to indicate tank volume levels.

The traditional resistive float sender uses a potentiometer attached to a float at the end of an actuating arm to provide a level indication. This technology interfaces with the instrument cluster’s fuel gauge which is typically a coil driven needle gauge. As the resistive float sender’s resistance changes with level, the current through the coil in the gauge changes causing a deflection of the needle. This approach has been used for many years.
Fluid-Trac® uses ultrasonic technology to generate a high frequency sound wave and measure the time for the echo to reflect off of the liquid’s surface and return. The distance from the level sensor to the fuel is calculated based on the speed of sound. The measured distance is converted into a voltage that drives the fuel gauge based on a strapping table contained in the level sensor.

• More Accurate: Distance accuracy of +/- 0.125 inches (1/8th inch).

• More Reliable: Fluid-Trac® is non-contacting. Resistive float sender have a wiper that slides across a resistive strip that with time can wear and cause intermittent or complete loss of the signal.

• Non-Invasive: Fluid-Trac® mounts to the same opening as the resistive float sender, but does not protrude into the tank.

• Easier to Install or Service: Fluid-Trac® has no components to protrude into the tank that need to be bent for removal.

• Digital Filtering: Digital filtering eliminates errors due to liquids sloshing in mobile tanks.

• Tank Profiling: Factory programmable strapping tables for unique tank shapes.