Radiation Protection Officer dental radiology basic Test exam
Radiation Protection Officer dental radiology - basic Test exam Frits Pleiter 20/10/2021 00: 59 radiation protection officer - thk 1
Question 41 Equivalent dose rate (in m. Sv per m. As) at a distance of 1 m from the focus. tube voltage thickness aluminum filter 1 mm 2 mm 3 mm 0. 07 0. 05 0. 03 0. 15 0. 09 0. 05 0. 20 0. 13 0. 08 50 k. V 70 k. V 90 k. V Data: tube voltage filter tube current exposure time distance focus - skin 90 k. V 3 mm aluminum 6 m. A 0. 3 seconds 35 cm Calculate the equivalent skin dose per X-ray photo. 20/10/2021 00: 59 radiation protection officer - thk 2
Evaluation of question 41 reading figure A at 90 k. V and 3 mm aluminum 0. 08 m. Sv/m. As at 1 meter (1 pt) m. As value = 6 m. A × 0. 3 s = 1. 8 m. As (1 pt) equivalent dose at 1 meter = 0, 08 m. Sv/m. As × 1. 8 m. As = 0. 14 m. Sv (1 pt) equivalent dose at 35 cm = 0. 35 m = 0. 14 m. Sv × (1 m / 0. 35 m)2 = 1. 2 m. Sv (1 pt) 20/10/2021 00: 59 radiation protection officer - thk 3
Question 42 A dental practice has a single intra-oral X-ray device that is subject to registration. For 50% of the photos, the X-ray beam is directed perpendicular to the double-glass window in the outer wall adjacent to the public road. Data: number of photos per year 2000 average tube voltage 90 k. V average m. As value 1, 5 m. As per photo filter 3 mm aluminum distance focus - road 3 meters thickness double glass 11 mm the contribution of scatter radiation can be neglected Check by means of calculation whether or not the shielding effect of the double glass in the window is sufficient to comply with the dose limit for the environment. 20/10/2021 00: 59 radiation protection officer - thk 4
Evaluation of question 42 reading figure A at 90 k. V and 3 mm aluminum 0. 08 m. Sv/m. As at 1 meter equivalent dose for 2000 / 2 = 1000 photos 1000 × 0, 08 m. Sv/m. As × 1, 5 m. As = 120 m. Sv at 1 meter equivalent dose at 3 meters = 120 m. Sv × (1 m / 3 m)2 = 13 m. Sv reading figure B at 90 k. V and 11 mm glass T = 0. 3 annual effective dose on the street = 13 m. Sv × 0. 3 = 4 m. Sv annual limit in case of registration = 10 μSv insufficient shielding 20/10/2021 00: 59 radiation protection officer - thk (1 pt) (1 pt) 5
20/10/2021 00: 59 radiation protection officer - thk 6
- Slides: 6