An internal test and an ________________ test must be performed on the radar instrument.

The correct choice to fill in the blank is "Calibrated" as it highlights the essential procedure of ensuring the radar instrument measures accurately. Calibration refers to the process of adjusting the readings of the radar device to align with known standards. This is crucial because the accuracy of speed measurements directly impacts law enforcement operations and public safety.

Calibration must be systematically performed to ensure that the equipment operates effectively under various conditions. It's essential for verifying that the instrument's readings are consistent and reliable, which in turn supports the legitimacy of any speed detection that is used in enforcement actions.

While other tests may focus on operational capabilities or the general accuracy of the systems but calibration specifically pertains to the precise adjustments needed for accurate functionality, making it the key element of tests performed on radar instruments.