摘要 |
<p>PHD 79-073 27 The temperature of the anode disc of a rotaryanode X-ray tube is continuously determined by means of the method apparatus in accordance with the invention. When the temperature exceeds a first limit value, the power of the X-ray tube is reduced to a fraction (for example, 80%) of the otherwise permissible power. When a second limit value of the anode disc temperature is exceeded, exposures are completely inhibited. In the case of exposures which are performed in rapid succession with a comparatively low power, it may occur that the anode disc temperature does not reach the second limit value, but that the mean value of the applied electric power is so high that the bearing of the rotary anode, and possibly also the joint between the anode shaft and the rotor, is overloaded. Overloading is prevented by the fact that the mean value of the power applied to the X-ray tube is also monitored, the exposure being inhibited when this mean value is too high.</p> |