1. Automotive Applications of Level Sensors Group: Calcium δ Eric Black Daniel Carter

2. Introduction • Level sensors are not only used in Industrial and Chemical Applications • Common household items use them as well • These sensors range from simple mechanical devices to electronic or radiating tools

3. Level Sensors on Cars • Cars contain two of the main kinds of level sensors • Float sensor • Visual sensor • The float sensor is found in the gas tank, whereas there are a few visual sensors under the hood of the car

4. Gas Tank Float Sensor • Initially, the float is at top of tank • The attached wiper is closer to negative side of terminal • Less resistance • More current • Hotter Heating coil • Pulls Bimetallic strip so dashboard gauge displays full

5. Gas Tank Float Sensor • As fuel leaves tank, float lowers • Wiper moves further down resistor • More resistence • Less current • Coil cools • Strip pulls with contracting metal

6. Gas Tank Float Sensor • Finally, after float hits bottom of tank, wiper is pulled to far right • Highest resistance • Lowest current • Coolest heating coil • Strip pulled gauge to empty

7. Gas Tank Float Sensor • Pros: • Relatively simple mechanical design • Good for estimating level of fuel • Cons: • Inaccurate when: • Tank is completely full • Tank is near empty • Doesn’t measure precise tank volume

8. Level Gauges Under the Hood • Under the hood of a car, there are ways to check the level of various other fluids • Oil • Transmission • Coolant / Antifreeze • Windshield washer fluid • These are checked using visual level gauges

9. Dipsticks • Dipstick is inserted into engine • Then removed with oil residue on tip • Tip is marked with “full” and “add oil” markings • Checking transmission fluid is similar • Similary to the fuel tank float meter: • Good for estimating fluid level • Not a precise measurement of volume

10. Container Markings • Small tanks under the hood containing windshield washer fluid and coolant have markings on the sides • Only good for level estimation • Can’t measure precise fluid volume