SLAA907D September   2019  – December 2021 PGA450-Q1 , PGA460 , PGA460-Q1 , TDC1000 , TDC1000-Q1 , TDC1011 , TDC1011-Q1 , TUSS4440 , TUSS4470

 

  1.   Trademarks
  2. 1What is Ultrasonic Time-of-Flight Sensing?
    1. 1.1 Principles of Ultrasound
    2. 1.2 Why Use Ultrasonic Sensing?
    3. 1.3 How Does Ultrasound Compare to Other Sensing Technologies?
    4. 1.4 Typical Ultrasonic-Sensing Applications
  3. 2Ultrasonic System Considerations
    1. 2.1 Introduction to the Ultrasonic System
    2. 2.2 The Ultrasonic Echo and Signal Processing
    3. 2.3 Transducer Types
    4. 2.4 Transducer Topologies
    5. 2.5 Transducer Frequencies
    6. 2.6 Transducer Drive (Transformer Drive & Direct Drive) and Current Limit
    7. 2.7 Pulse Count
    8. 2.8 Minimum Detection Range
  4. 3What Factors Influence Ultrasonic Sensing?
    1. 3.1 Transmission Medium
    2. 3.2 Acoustic Impedance
    3. 3.3 Radar Cross Section
    4. 3.4 Ambient Conditions (Temperature, Humidity, Debris)
    5. 3.5 Device Selection
  5. 4Additional Resources
  6. 5Revision History

1.2 Why Use Ultrasonic Sensing?

Ultrasonic sensors can detect a variety of materials, regardless of shape, transparency, or color. The only requirement for ultrasonic sensing is that the target material is a solid or liquid. This enables contactless detection of:

  • Metal
  • Plastic
  • Glass
  • Wood
  • Rocks
  • Sand
  • Oil
  • Water
  • Other hard, non-sound absorbent materials

These materials are able to reflect sound back towards the sensor through the air. Certain objects can be more difficult to detect, like angled surfaces that direct the echo away from the sensor, or permeable targets like sponge, foam, and soft clothing. These absorb more reflected ultrasonic energy.