Which of the following is NOT a characteristic that needs to be tested in radiation therapy equipment?

In the context of radiation therapy equipment, testing characteristics is crucial for ensuring safety and efficacy in treatment delivery. Software features, while important for the functioning of equipment, are generally not classified as a characteristic that undergoes physical testing in the same manner as mechanical, radiological, or electrical characteristics.

Mechanical characteristics involve the physical components of the machinery, such as the integrity of moving parts and alignment of equipment, which are vital for accurate treatment delivery.

Radiological characteristics are essential for verifying that the radiation output is consistent, accurate, and conforming to standard treatment protocols, as this directly impacts dose delivery to the patient.

Electrical characteristics are equally important, assessing power supply, grounding, and circuit integrity to ensure the equipment operates safely without risk of failure or hazards.

Thus, while software issues are monitored and require validation, they are typically more related to performance checks or updates rather than the physical characteristics of the equipment itself that require structured testing protocols.