[Measuring device for rapid determination of tube peak voltage and the switch-on time of roentgen equipment].

A prototype of a measuring device is described, which reads the tube peak voltage and the switch-on time of x-ray units by means of two radiation detectors with different energy dependences due to detector materials (Caesium Iodine and Silicon). With a storage oscilloscope the curves of the tube voltage and the relative absorbed dose rate of intensifying screens can be displayed. The measuring range of the tube peak voltage is 60 kV to 150 kV. It is possible to measure exposure times of radiography equipment above 2 ms wit sufficiently low uncertainty. The tube peak voltage has been read with a relative uncertainty below 5% for almost all dose rates, which arise in practical application of medical x-ray units, and its calibration is made by means of x-ray apparatus with tube voltage reading, which has been compared to a Ge(Li) spectrometer. The stability of tube voltage reading of the measuring device is only effected by radiation damage of the detectors after a long time of utilization. The small diameter of the probe permits the accommodation of other probes, ionization chambers, phantoms, etc. in the radiation field at the same time.