Units and Quantities
Exposure (X) | Amount of ionization per mass of air due to X-rays and gamma rays. | Roentgen (R) |
Absorbed Dose (D) | Amount of energy imparted by radiation per unit mass. | SI: Gray (Gy) |
Kerma (K) | Kinetic Energy Released per unit MAss Kinetic energy transferred by uncharged particles to charged particles per unit mass. | SI: Gray (Gy) |
Equivalent Dose (HT) | A measure of absorbed dose weighted for the biological effectiveness of the types(s) of radiation (relative to the low LET photons and electrons) to produce stochastic health effects in humans. | SI: Sievert (Sv) |
Dose Equivalent (H) | A measure of absorbed dose weighted for the biological effectiveness of the types of radiation (relative to low LET photons and electrons) to produce stochastic health effects in humans. | Sievert (Sv) |
Effective Dose (E) | A measure of equivalent dose, weighted for the biological sensitivity of the exposed tissues and organs (relative to whole body exposure) to stochastic health effects in humans. | Sievert (Sv) |
| Effective Dose Equivalent (HE)  | A measure of equivalent dose, weighted for the biological sensitivity of the exposed tissues and organs (relative to whole body exposure) to stochastic health effects in humans. | Sievert (Sv) |
Conversion Factors
Energy
- \(Joule (J) = Electron Volt (eV) \times 1.602 \times 10^{-19}\)
Radiation Units
- Air Collision Kerma (Gy)
Temperature
- Degrees Kelvin (K) = Degrees Celsius (C) + 273.16
Units
| Physical Quantity | Unit Name | Symbol |
| Charge (electric) | Coulomb | C |
| Dose | Gray | Gy (=J/kg) |
| Energy | Joule | J |
| Energy | Electron Volt | eV |
| Exposure | Roentgen | R |
| Length | Meter | m |
| Mass | kilogram | kg |
| Time | second | s |
| Time | minute | min |
Metric Unit Prefix
| Prefix | Symbol | Base 10 | Decimal |
| yotta | Y | 1024 | 1,000,000,000,000,000,000,000,000 |
| zetta | Z | 1021 | 1,000,000,000,000,000,000,000 |
| exa | E | 1018 | 1,000,000,000,000,000,000 |
| peta | P | 1015 | 1,000,000,000,000,000 |
| tera | T | 1012 | 1,000,000,000,000 |
| giga | G | 109 | 1,000,000,000 |
| mega | M | 106 | 1,000,000 |
| kilo | k | 103 | 1,000 |
| hecto | h | 102 | 100 |
| deca | da | 101 | 10 |
| 100 | 1 | ||
| deci | d | 10-1 | 0.1 |
| centi | c | 10-2 | 0.01 |
| milli | m | 10-3 | 0.001 |
| micro | μ | 10-6 | 0.000,001 |
| nano | n | 10-9 | 0.000,000,001 |
| pico | p | 10-12 | 0.000,000,000,001 |
| femto | f | 10-15 | 0.000,000,000,000,001 |
| atto | a | 10-18 | 0.000,000,000,000,000,001 |
| zepto | z | 10-21 | 0.000,000,000,000,000,000,001 |
| yocto | y | 10-24 | 0.000,000,000,000,000,000,000,001 |