Ultrasonic Sensor:
These sensor are designed to generate high frequency sound waves and receives the echo reflected by the target. These sensors are used in a wide range of applications and very useful when it is not important the detection of colors, surface texture or transparency.
Advantages of Ultrasonic Sensor:
1. The output value is linear with the distance between the sensor and the target.
2. Sensor response is not dependent on the colors, transparency of objects, optical reflection properties or by the surface texture of the object.
3. These sensors are designed for contact free detection.
4. Sensors with digital (ON/OFF) outputs have excellent repeat sensing accuracy.
5. Accurate detection even of small objects.
6. Ultrasonic sensors can work in critical conditions such as dirt and dust.
7. They are available in cuboid or cylinder forms which is better for a freedom design.
Disadvantages of Ultrasonic Sensor:
1. Ultrasonic sensors must view a high density surface for good results. A soft surface like foam and cloth has low density and absorb the sound waves emitted by the sensor.
2. It could have false responds for some loud noises such as air hoses.
3. The ultrasonic sensors have a response time with a fraction less than other types of sensors.
4. An ultrasonic sensor has a minimum sensing distance, which should be taken into consideration when you choose the sensor.
5. Some changes in the environment can affect the response of the sensor (temperature, humidity, pressure, etc.)