I see ultrasonic transducers used in many Arduino and similar applications for proximity sensing.
I wonder what is the lifespan of such devices (Chinese cheap models, not Chinese more expensive ones) when used about once a second.
I don't consider the use outside specifications, only regular use as from the datasheet.
As plus, additional data about more rugged transducers like the ones used in cars for parking would be appreciated.
What is the lifespan of ultrasonic transducers like the ones used in hobby projects?
Piezoceramic transducers (the more expensive ones) have a long life. They also have less sensitivity. They are usually stacked with acoustic damping material at the rear of the transducer and epoxy with hollow micro spheres in the front of the transducer element as an impedance matching mechanism.
Diaphragm ultrasonic transducers (less expensive ones) usually have the flexure element (diaphragm) exposed to the air. They have a higher sensitivity, but are more vulnerable to environmental conditions such as dust, moisture, and aging of the diaphragm. As a result, these have a shorter life span than the piezo types.
Ultrasonic transducers that use piezoelectric ceramics can be expected to have long lifetimes. These ceramics do age but in a logarithmic way. Thus a parameter, such as the capacitance of the transducer, might change 1% from 10 to 100 days but will change 1% from 100 to 1000 days and so on. By the time that you receive the transducer, its age will be enough so that this time aging will not be of concern. Otherwise, if its construction is good and it is not subjected to excessive temperature or voltage, it should last essentially forever. I worked with sonar transducers using such ceramics that were expected to last at least 20 years. The only failure modes that I saw were water intrusion due to failed seals, connection failures due to poor soldering and cracking due to excessive stress.
