Selection of Ultrasonic transducer and what need we pay attention

Selection requirements
When is selecting and installing an ultrasonic sensor it is necessary to clarify some basic conditions, otherwise it will directly affect the measurement result of the ultrasonic sensor.

Detection range and size
The size of the object to be detected directly affects the detection range of the piezoelectric ultrasonic transducer. The ultrasonic sensor must detect a certain level of sound before it can be output. The large part can reflect most of the sound to the ultrasonic sensor, so that the sensor can detect this part at its farthest sensing distance. Small parts can only reflect a small part of the sound, resulting in a greatly reduced sensing range.

If the liquid level is stationary and perpendicular to the ultrasonic transducer depth measurement surface, it is easy to detect the liquid. If the liquid level fluctuates greatly, the response time of the sensor can be extended to take the average value of the fluctuation change to obtain a more consistent reading. However, the ultrasonic sensor cannot accurately detect the liquid on the surface of the foam, because the foam will deviate the direction of sound propagation.

At this time, the reverse ultrasonic mode of the ultrasonic sensor can be used to detect irregularly shaped objects. In reverse ultrasound mode, the ultrasound sensor detects a flat background, such as a wall. Any object passing between the sensor and the wall will block the sound waves. The sensor can recognize the existence of the object by detecting the interference.
The temperature-induced attenuation sensor is also designed with a temperature compensation function to regulate the slow change of the ambient temperature. However, it cannot adjust for temperature gradients or rapid changes in ambient temperature. Whether there is vibration around the sensor itself or the vibration of nearby machines may affect the accuracy of measuring distance. A rubber anti-vibration device can be used to reduce such problems when is installing the ultrasonic sensor. Sometimes it guide rails can also be used to eliminate or reduce component vibration.

Misdetection caused by the environment nearby objects may reflect sound waves. To accurately detect target objects, the influence of nearby sound reflecting surfaces must be reduced or eliminated. In order to avoid misdetection of nearby objects, many ultrasonic sensors are equipped with LED indicator lights, which are used to instruct operators during installation to ensure that the sensor is correctly installed and reduce the risk of misdetection. The ultrasonic sensor performs non-contact, non-wearing detection on the detected object. It can detect transparent or colored objects, metallic or non-metallic objects, solid, liquid and powdery substances. Its detection performance is hardly affected by any environmental conditions, including smoke and dust environment and rainy days.