What is resonance time?
Transmission-reception combined type ultrasonic sensors allow a single sensor to be used for both transmission and reception.
Even after the input signal stops, the sensor cannot receive waveforms until the sensor stops vibrating.
This duration during which the sensor continues to vibrate is called the resonance time. If the sensor has a long resonance time, it will not be able to detect short distances.
•The resonance characteristics are also affected by the method used to secure the sensor in place. (Refer to Basic knowledge: Usage.)
What is the proper distance for a specific reflection target?
Detection target and detection distance
Ultrasonic sensors work with targets of any material or color. They are able to detect objects made of transparent glass or acrylic. Nevertheless, the reflection rate will differ according to the characteristics of the reflection target.
•Reflected waves cannot be measured while the receiver is receiving direct waves.
→Short distance limit
•If an object is too far away, its reflected waves may be too weak to be measured.
→Long distance limit