Ultrasonic Sensors
Description
Ultrasonic sensors are electronic devices, which are used to evaluate a target’s parameters by generating the ultrasonic waves and receiving them as they get echoed back from the target. The parameter evaluated is usually the distance, speed or presence of the target. This evaluation is obtained by calculating the time interval between the waves that are sent and the ones that are received. The sensors generally consist of a piezoelectric crystal or quartz crystal, which converts electrical signals to acoustic, signals of higher frequency and vice versa. The output electrical signals can be fed to display device for reading the measurements. Ultrasonic sensors can detect any material, regardless of color, from transparent bottles to black tires.
Types
Ultrasonic sensors are classified as following:
Proximity ultrasonic sensors - An object within the prefixed range of the sensor will be detected and accordingly the output signal is generated; the detection point is not affected by the target size, color, material or its degree of reflectivity
Ranging ultrasonic sensors - The distance of the moving object is measured by the sensor by calculating the time gap between the transmitted signal and the echo wave
Applications
The following are the applications of ultrasonic sensors:
For sonar, humidifiers, burglar alarms, medical ultrasonography and non-destructive testing applications
In many process plants and automated factories to detect the target presence and counting applications
For controlling liquid levels of tanks and containers in many industrial applications
In vehicle detection for car washing and automotive assembly applications
For robotic sensing applications
For loop control, tension control and winding applications in textile industry
For counting the number of persons moving inside or outside access areas