caa a22 4500 397503431 CHVBK 20180308164538.0 cr unu---uuuuu 161202e19950101xx s 000 0 eng 10.1093/oxfordjournals.rpd.a082530 doi 0144-8420 pii (NATIONALLICENCE)oxford-10.1093/oxfordjournals.rpd.a082530 A Non-Invasive Method to Control the Tube Current Calibration of Diagnostic Radiology Equipment [Elektronische Daten] [N.J. Uys, C.P. Herbst, A. van Aswegen, M.G. Lötter, M.A. Sweetlove, J.F.K. de Villiers] The correct calibration of the tube current of diagnostic X ray equipment is important to ensure optimal image quality. This decreases the number of retakes which will reduce the radiation dose to the patient and the radiation worker. The direct measurement of the tube current is time-consuming and is not part of the non-invasive quality control programme. A technique was therefore developed where readings from a NERO system were used to control the tube current calibration of diagnostic X ray equipment. If the tube potential and timer are accurately calibrated, it is possible to derive the consistency of the tube current calibration from the exposure measurement. The exposure of 27 X ray machines was measured using a 65 cm focus-detector distance at 80 kV. Previous tests on the different machines showed that the calibration of the timer and tube potential was correct within 5%. The half value layer (HVL) for each machine was determined at 80 kV. The range of HVL values was from 2.44 to 3.62 mm Al at 80 kV and the corresponding exposure from 0.06 to 0.19 mGy (mA.s)-1 (95% confidence level). If the exposure is not within these limits with a correct tube potential and timer calibration, it will be indicative of a faulty tube current value. A non-invasive method was developed to control the tube current calibration of diagnostic X ray machines and this study showed that it could be implemented successfully. Radiation Protection Dosimetry Uys N.J. aut Herbst C.P. aut van Aswegen A. aut Lötter M.G. aut Sweetlove M.A. aut de Villiers J.F.K. aut Radiation Protection Dosimetry Oxford University Press 57/1-4(1995-01-01), 227-229 0144-8420 57:1-4<227 1995 57 rpd https://doi.org/10.1093/oxfordjournals.rpd.a082530 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1093/oxfordjournals.rpd.a082530 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Uys N.J. aut NATIONALLICENCE 700 1- Herbst C.P. aut NATIONALLICENCE 700 1- van Aswegen A. aut NATIONALLICENCE 700 1- Lötter M.G. aut NATIONALLICENCE 700 1- Sweetlove M.A. aut NATIONALLICENCE 700 1- de Villiers J.F.K. aut NATIONALLICENCE 773 0- Radiation Protection Dosimetry Oxford University Press 57/1-4(1995-01-01), 227-229 0144-8420 57:1-4<227 1995 57 rpd Metadata rights reserved CC BY-NC-4.0 http://creativecommons.org/licenses/by-nc/4.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-oxford