What is the maximum variability allowed for a timer that exceeds 10 milliseconds?

The maximum variability allowed for a timer that exceeds 10 milliseconds is set at 5%. This standard is established to ensure that the timing accuracy of radiographic equipment remains high, as even small errors in timing can significantly impact radiation dose, image quality, and patient safety.

In radiographic practice, the timer's performance is crucial for achieving consistent exposure levels, as it directly influences how long the X-ray beam is activated. A 5% variability means that if the timer is set for a specific duration, the actual time allowed to elapse can vary by no more than 5% of that setting, thereby maintaining the precision required for effective imaging. This variability threshold strikes a balance between practical operational limits and the need for reliable performance in clinical settings.