Formulas & Numbers Flashcards
Annual General Public Exposure
0.5 rem / year
5 mSv / year
Annual Occupational Exposure
5 rem / year
50 mSv / year
Annual Radiograph Student Exposure <18
0.1 rem / year
1 mSv annually
Lifetime Occupational Dose
1 rem x age in years
10 mSv x age in years
Annual Lens of Eye Dose
15 rem / year
150 mSv / year
Annual Skin / Hands & Feet Dose
50 rem / year
500 mSv / year
Pregnant Worker Dose
.5 rem / gestation
5 mSv / gestation
FETAL DOSE
- TOTAL
- MONTH
.5 rem / gestation
.5 mSv / gestation
.05 rem / month
.05 mSv / month
- SID Accuracy:
- Collimation Accuracy:
- PBL Accuracy:
- Alignment Accuracy:
- 2%
- 2%
- 1-2%
- 1%
Regular Apron Lead Equivalency
Minimum & Recommended
25 mm Pb Min.
0.5 mm Pb Rec.
Fluro Apron Lead Equivalency Minimum
Regular & Portable
Regular: 0.5 mm Pb min.
Portable: 0.25 mm Pb min.
Neck/Thyroid Lead Equivalency
0.5 mm Pb
Gloves Lead Equivalency
0.25 mm Pb
Eyeglasses Lead Equivalency
0.35 mm Pb
Fluro Drape Lead Equivalency
Minimum & Recommended
0.25 mm Pb min.
0.5 mm Pb rec.
Buckey Slot Cover Lead Equivalency
Minimum & Recommended
0.25 mm Pb min.
0.5 mm Pb rec.
Glass Window Lead Equivalency
1.5 mm Pb
Filtration
Inherit:
Total Below 50 kVp:
Total 50-70 kVp:
Total 70+ kVp:
0.5 mm Al
Below 50 kVp: 0.5 mm Al
50 - 70 kVp = 1.5 mm Al
70+ kVp = 2.5 mm Al
SSD Fixed X-Ray Minimum Distance:
12 inches
30 cm
SSD Portable X-Ray Minimum Distance:
12 inches
30 cm
SSD Fixed Fluro Minimum Distance:
15 in
38 cm
SSD Portable Fluro Minimum Distance:
12 in
30 cm
X-Ray Collimator to Skin Minimum Distance
6 in
15 cm
Portable Cord Length
2 Meters
6 Ft
72 in
180 cm
Scatter Intensity
1/1000
.001 or .1%
OF PRIMARY BEAM AT RIGHT ANGLE & 1 METER FROM PATIENT
Maximum Tabletop Exposure Rate in Fluro
10R / min @ 1 meter
Maximum Leakage Radiation From Tube Housing
100 mR / hour @ 1 meter
1 mGy / hour @ 1 meter
Primary Barrier Lead Equivalent
1/16in
.16 cm
1.6 mm
Secondary Barrier Barrier Lead Equivalent
1/32 in
.08 cm
.8 mm
Overlap of Primary & Secondary Barriers
1/2 in
1.25 cm
Image Intensifier Lead Equivalency
2 mm
Hematopoietic Dose
1 - 10 Gy
within 3-6 weeks
Gastrointestinal Dose
> 6 - 50 Gy
within 1 week
Cerebrovascular Dose
> 50 Gy
within hours/days
Q.F.:
X-RAY:
GAMMA:
BETA:
ALPHA:
FAST NEUTRONS:
X-RAY: 1
GAMMA: 1
BETA: 1
ALPHA: 20
FAST NEUTRONS: 10
Mitotic Delay Dose
.01 Gy
10 mGy
Instant Death Dose
1000 Gy
in seconds
Reproductive Death Dose
1 - 10 Gy
Blood Change Dose
.25 Sv
25 rem
Erythema Dose Range
2.0 - 6.0 Sv
200 - 600 rem
Temporary Sterility Dose
2.5 Sv
250 rem
Doses For:
LD 50/30:
LD 50/60:
LD 100:
LD 50/30: 300 rad (3.0 Gy)
LD 50/60: 350 rad (3.5 Gy)
LD 100: 1000 rad (10 Gy)
Sublethal Dose Range
200-300 rad
2-3 Gy
Superlethal Dose Range
600 - 1000 rad
6-10 Gy
Reduction in Sperm Count & Suppressed Menstruation Dose
10 rad
.1 Gy
100 mGy
Temporary Sterility in Gonads
200-250 rad
2 - 2.5 Gy
Permanent Sterility in Testes & Gonads
500 - 600 rad
5 - 6 Gy
Cataract Formation Dose
- Single
- Fractional
Single: 200 rad / 2 Gy
Fraction: 1000 rad / 10 Gy
Preimplantation Embryonic Death Dose
.05 - .15 Gy
5 - 15 rad
Second & Third Trimester Embryo Death Dose
> 200 mSv
NRCP Report #105
Radiation Protection for Personnel
NRCP Report #102
Exposure Reduction, Filtration & Shielding Requirements
NRCP Report #147
Barrier Thickness
Roentgen (R) to Coulombs /kg
Coulombs /kg to Roentgen (R)
RAD to Gray (Gy)
Gray (Gy) to RAD
REM to Sievert (Sv)
Sievert (Sv) to REM
Conventional / Traditional Units Are:
Roentgen (R) = Exposure Air
rad = Radiation Absorbed Dose
rem = Radiation Equivalency / Biological Dose
Curie (Ci) = Radioactivity
SI Units Are:
Coulombs/Kg (C/kg) = Exposure Air
Gray (Gy) = Radiation Absorbed Dose
Sievert (Sv) = Radiation Equivalency / Biological Dose
Becquerel (Bq) = Radioactivity
Sieverts to Millisieverts
- # of Sieverts x 1000 = mSv
Millisieverts to Sieverts
- # of millisieverts x .001
Formula for Maximum Electrons In Orbital Shell
2n^2
Centi =
Milli =
Centi:
1/100 or .01
Milli:
1/1000 or .001
Power Formula
P = IV
Ohms Formula
V - IR
Step-Up Transformer
A. Turns Ratio
B. Voltage Increase:
A. 700:1
B. 500-1000
*Converts V to KV
Step-Down Transformer Voltage
8 - 12 V
Voltage & Turns Ratio Formula
Ripple Effect & Efficiency:
A. Single Phase:
B. Three Phase (6p):
C. Three Phase (12p):
D. High Frequency:
*MINUS RIPPLE FACTOR FROM 100 = EFFICIENCY