What device failure might cause electrical flow through the x-ray tube to measure in volts instead of kilovolts?

The measurement of electrical flow through the x-ray tube in volts instead of kilovolts indicates that the voltage is not being properly increased to the levels necessary for x-ray production. This typically points to the malfunction of the step-up transformer, which is responsible for increasing the voltage from the output of the primary circuit to the kilovolt range required for the tube.

In a functioning system, the step-up transformer takes the lower voltage from the electrical supply and boosts it to the high kilovoltage levels needed to generate x-rays. If this transformer fails or does not operate correctly, the voltage may not be stepped up adequately, resulting in measurements in volts rather than the required kilovolts. This would significantly impact the x-ray tube's ability to produce x-rays, as it relies on high voltage for the acceleration of electrons towards the anode.

Other components, such as the rectifier or generator, do play important roles in the overall x-ray circuit, but their failure would not specifically account for a reduction in measured voltage to the volt scale instead of kilovolts. The step-down transformer also operates at lower voltage levels, which is not relevant to producing high voltage for x-ray production. Thus, the malfunction of the step-up transformer is the most direct