Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Sherer Ch4
| Question | Answer |
|---|---|
| monitoring of radiation exposure to any person occupationally exposed regularly to ionizing radiation | personal dosimetry |
| when is personnel monitoring required? | whenever radiation workers are likely to risk receiving 10% or more of the annual occupational EfD of 50mSv in any single year as a consequence of work |
| where does one wear a personal dosimeter when no apron is worn? | attached to clothing on front at collar level appx to location of maximal rad dose to thyroid & head & neck |
| where does one wear a personal dosimeter when an apron is worn? | worn outside the apron at collar level on anterior surface of body. |
| where does one wear a second monitor when an apron is worn? | worn under apron at waist level to monitor EqD to trunk. |
| where does a embryo/fetal dosimeter | pregnant diagnostic techs issued second monitor to record dose to abdomen during gestation. |
| required when hands necessary to be near beam | thermoluminescent dosimeter (TDL) ring badge |
| where is Record of Radiation Exposure kept? | Part of employment history |
| record whole-body exposure accumulated at a low rate over a long period of time. | film badges |
| soft radiations cast what kind of image on dosimetry film? | more pronounced image |
| what permits estimation of energy of radiation? | Density of the cast image |
| depending on shape and density on film what can be learned from dosimetry film? | if radiation was single or repeated exposures |
| sensitive to doses ranging from 10mrem - 500rem | film badge |
| used to measure optical density of dosimetry film | densitometer |
| how is Amt of radiation exposed determined? | by locating the exposure value of control film to similar OD on characteristic curve |
| serves as basis for comparison with remaining film badges after they have been returned to the monitoring company for processing | control badge |
| lists the deep, eye, & shallow occupational exposure of each person in facility as measured by exposed monitors. Provide a continuous audit of actual absorbed radiation EqD | personnel monitoring reports |
| when changing jobs, what must a radiographer do? | worker must convey data pertinent to accumulated permanent EqD to new employer so info can be placed on file |
| what is the main advantage of film badges? | film itself constitutes a permanent legal record for personnel exposure. Personnel monitoring reports reviewed by RSO |
| advantages of film badge? | reasonably economical, few $ per month. Film badge can discriminate among types of radiation & energies of them. Mechanical integrity. |
| main disadvantages of film badges | temp & humidity extremes can cause in inaccurate reading. no instant results. |
| most sensitive to photons at 50keV | film badge |
| Most common type of monitor used | OSL |
| What does OSL stand for? | OPTICALLY STIMULATED LUMINESCENCE |
| Contains aluminum oxide (Al2O3) detector (thin layer). | OSL |
| Laser light becomes luminescent in proportion to amt of rad exposure received | OSL reading |
| Can be worn up to 1 year, typically done 2 months at a time. | OSL |
| 3 types of filters in OSL | aluminum, tin, & copper |
| which element filters the most radiation out in the OSL? | copper |
| which element filters the least radiation out in the OSL? | Aluminum |
| physically correlate with different penetration depths | energy ranges classified as deep eye, and shallow |
| accurate readings as low as 1mrem | OSL |
| most sensitive type of personal dosimeter | POCKET IONIZATION CHAMBER (pocket dosimeter) |
| Sensitive to 0mR | pocket dosimeter |
| provides immediate exposure readout for workers in high exposure areas | pocket dosimeter |
| advantages of pocket dosimeter | Compact, easy to carry, convenient to use. Ideal monitoring devices for procedures of relatively short duration |
| disadvantages of pocket dosimeter | expensive. Must be read daily. Can give false high if subjected to mechanical shock. Provide no permanent legal record |
| sensing material of TLD | lithium fluoride (LiF) |
| measures amt of ionizing radiation by heating crystals to free trapped energized electrons and record amt of light emitted to crystals | TLD Analyzer |
| sensitive to exposures as low as 1.3x10-6C/kg (5mR) | TLD |
| FX of Humidity, pressure, and normal temp changes on TLD | none |
| May be worn up to 3 months | TLD |
| disadvantages of TLD | high initial cost. Readout process destroys stored information. Necessity of using calibrated dosimeters. No permanent legal record |
| Most common type of survey meter that incorporates ionization chamber | “cutie pie” |
| are 3 types of gas filled radiation detectors that serve as field instruments | Cutie Pie, GM meter, & proportional counter |
| measures 1mR/hr – several thousand mR/hr | IONIZATION CHAMBER-TYPE SURVEY METER (CUTIE PIE) |
| both a rate meter device (measures exposure rate) used for area surveys & accurate integrating or cumulative exposure instrument. Measures x, gamma, and if properly equipped, beta rad | IONIZATION CHAMBER-TYPE SURVEY METER (CUTIE PIE) |
| Able to measure wide range of exposures within few seconds | IONIZATION CHAMBER-TYPE SURVEY METER (CUTIE PIE) |
| Without adequate warmup time, meter will drift & give inaccurate reading | Cutie Pie |
| o Cannot be used to measure exposures produced by typical diagnostic procedures because exposure times too short to permit meter to respond | Cutie Pie |
| serves no useful purpose in diagnostic imaging. Used in lab to detect alpha & beta rad & small amounts of low level rad contamination | PROPORTIONAL COUNTER |
| Primary portable rad survey instrument for area monitoring in nuc med facilities | GM Detector |
| Allows rapid monitoring, used to locate lost rad source or low-level contamination | GM Detector |
| Audible sound system alerts presence of rad | GM Detector |
| Tends to lose calibration over time, “check source” of weak, long-lived radioisotope located on one side of external surface to verify is constancy daily | GM Detector |
| Likely to saturate or jam when placed in very-high intensity rad area & give false reading | GM Detector |
Created by:
jen.studer
Popular Radiology sets