Chapter 5: Radiation Monitoring Flashcards
- relies on the ability of ionizing radiation to affect a density change on the film emulsion
amount of dose received by badge is a function of the degree of film blackening that takes place on surface of the film emulsion that lies under various forms of attenuating filters, such as tin or copper
monitor over extended period of time, inexpensive and reliable
provide permanent record - you have to send it in every month
Film badge
- functional component is lithium fluoride
readings are made by heating the lithium fluoride chip – once heated it is destroyed
monitor over extended period of time
no permanent record - extremity dosimeter
- nuclear medicine technologist
- worn for 3 mnths
- ring dosimeters
- glow curve plot
TLD
Thermoluminescent dosimeter
Thermo =
heat
luminescent =
light
immediate results
ionizing radiation to ionize gas chamber – discharges electrode
short term monitoring – no permanent record
prone to inaccurate readings because of rough handling
can be reused
Pocket Dosimeter
- utilizes aluminum oxide detector
laser light reads sensing material
filters made of aluminum, tin and copper
permanent record
OSL – Optically Stimulated Luminescence
Occupation exposure annual dose is
50 mSv
fetus monthly exposure is
0.5 mSv
entire gestation is how much
5.0 mSv
indicates below minimum measurable radiation
“M”
does nothing to protect you, just measures radiation level
Dosimeter
Most sensitive to least sensitive
-Pocket
- OSL
- TLD
- Film badge
to calculate your cumulative effective dose you do
your age x 10 millisivert
example: 24 x 10 = 240 smv
fluoro lead is how much
0.5 pb
lead in general radiology how much
0.25 pb
