Automotive Applications of Level Sensors

1
Automotive Applications of Level Sensors

• Group Calcium d
• 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
• Doesnt 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
• Cant measure precise fluid volume