HT measuring appts. for radiographic X=ray tube - has two radiation detectors covered by filters of differing absorption coefficients and feeding divider circuit

摘要

The device operates on an X-ray tube in a radiodiagnostic installation without the necessity of being connected in the H.T. circuit, and includes two radiation detectors (3,4) connected through respective current-voltage converters (7,8) to a common divider (9). The two detectors are covered by respective X-ray filters (5,6) of selected different absorption characteristics. The divider output is a measure of the X-ray tube H.T. and is applied through an analogue-digital converter (11) to a memory (12) and display (13). Regulation of the tube H.T. is also effected by coupling the divider output to a comparator (14) for comparison with a preset value (15), the comparator output controlling the tube radiology generator (2). Two filters used are conveniently copper of 0.7 and 1.5 mm thick. The function of divider output with tube H.T. is known and stored in the memory to enable comparison with the actual divider output.