What is any device that is permanently mounted in the prime equipment for testing purposes?

The correct answer is BITE, which stands for Built-In Test Equipment. A BITE is specifically designed to be permanently integrated into the main equipment for the purpose of conducting tests and diagnostics. This allows for continuous monitoring and assessment of the system's operational status. BITE can help in identifying malfunctions or performance issues within the equipment, providing valuable data to technicians for troubleshooting.

Devices referred to as testers or measurers, while used in testing applications, typically are not permanently mounted within the prime equipment. Instead, they are standalone instruments that can be connected and used as needed. This distinction is crucial, as the primary function of BITE is its seamless integration into the system, allowing for real-time feedback and evaluation without the need for external devices.