In Reply to: tube x-ray posted by Joel Inacio on 09/24/01 at 6:18 PM:
There are many failure modes that an X-ray tube can exhibit. The two most obvious ones are, and open filament, and gas entering the tube due to failure of the glass seals. Some not so obvious failures are, etching or pitting of the target metal at the focal spot, evaporated tungsten coating the inside surface of the glass, mechanical failure due to impact, and over-heating of the anode caused by operating at too high mA for too long of a time period. These failure modes can occur in stationary as as well as rotating anode tubes. Rotating anode tubes have some other failure modes that are related to the rotating anode, e.g., locked rotor, noisy bearings, defective stator coil/capacitor, and "tracking" along the anode at the focal spot. Some of these failure modes would cause either no X-ray output, weak X-ray output, or poor "quality" of the X-ray beam.
Hope this anwers you question....
Amery X-ray, Inc.