The flashcards below were created by user
sthomp88
on FreezingBlue Flashcards.
-
Units of radiation are used to define what 3 quantities of radiation?
- exposure
- dose
- dose equivalent
-
What are the 2 systems usedto define radiation measurements? (in order from oldest to youngest)
- traditional or standard system
- Systeme internatioale (SI)
-
What are the 3 traditional units of measurement?
- roentgen (R)
- radiation absorbed dose (rad)
- roentgen equivalent in man (rem)
-
What are the 3 SI units of measurement?
- coulombs/kilogram (C/kg)
- gray (Gy)
- sievert (Sv)
-
the measurement of ionization in air produced by x -rays
exposure
-
What is the traditional unit of exposure for x-rays
roentgen (R)
-
a way of measuring the radiation exposure by determining the amount of ionization that occurs in air
roentgen (R)
-
the quantity of x radiation or gamma radiation that produces an electrical charge of 2.58 z 10-4 coulombs in a kilogram or air at standard temperature and pressure conditions
Roentgen
-
true or false. In the roentgen (R) a known volume of air is irradiated.
true
-
the interaction of x-ray photons with air molecules results in______ or the formation of_______-
-
One roentgen is equal to the amount of radiation that produces how much ion pairs in 1 cubic centimeter of air?
about 2 billion, or 2.08 x 109 ion pairs in 1 cc of air
-
the roentgen measures the amount of energy that____________of an organism, but does not describe the________________
- reaches the surface
- amount of radiation absorbed
-
the roentgen is essentially limited to measurements in____
air
-
by definition the roentgen is only used for_______ and ________ and does not include any other type of radiation
-
What is the SI unit for exposure equialent to the roentgen (R)?
there is none
-
How is exposure stated in the SI system?
coulombs per kilograms (C/kg)
-
a unit of electrical charge in the SI system
coulomb (C)
-
What measures the number of electrical charges, or the number of ion pairs in 1 kg of air?
coulombs per kilogram (C/kg)
-
How is the conversion for roentgen and coulombs per kilogram expressed?
- 1 R = 2.58 x 10-4 C/kg
- 1 C/kg = 3.88 x 103 R
-
the amount of energy absorbed by a tissue
dose
-
what is the traditional unit for dose?
radiation absorbed dose (rad)
-
true or false. the rad is not restricted to air, and can be applied to all kinds of radiation
true
-
a special unit of absorbed dose that is equal to the deposition of 100 ergs of energy per gram of tissue (100 erg/g)
rad
-
In using the SI unit, one rad is equivlent to how many joules per kilogram?
0.01 J/kg
-
What is the SI unit equivalent to the rad?
the gray (Gy), or 1 J/kg
-
How is the conversion for rad and Gy expressed?
- 1 rad = 0.01 Gy
- 1 Gy = 100 rads
-
measurement used to compare the biologic effects of different types of radiation
dose equivalent
-
What is the traditional unit of the dose equivalent?
roentgen equivalent in man (rem)
-
the product of absorbed dose (rads)and a quality factor specific for the type of radition
rem
-
What is used to place the exposure effects of different types of radiatin on a common scale?
Quality Factor (QF) or dimensionless multiplier
-
Why is does each type of radiation have a specific quality factor?
because different types of radiation produce different types of biologic damage
-
what is the QF for x-rays equal to?
1
-
What is the SI unit equivalent of the rem?
sievert (Sv)
-
how is the conversion for the rem and seivert expressed?
- 1 rem = 0.01 Sv
- 1 Sv = 100 rems
-
what prefix is used in dental radiography to express small quantities of exposure, dose and dose equivalent?
milli
|
|