Performance properties DO degrade
Epoxied transducers DO ...
The TR-89/B Series Transducers are rugged electroacoustic devices
designed for the efficient generation of ultrasonic energy in air. They
are ideally suited for a wide variety of low power, general purpose
applications such as ultrasonic intrusion alarms, proximity detection
devices, remote control devices, and energy management systems.
The Transducers consist of a one piece housing ...