ABSTRACT
This section describes the symbols used throughout the homepage.
Furthermore it contains conversion between various units
Following units are used throughout the homepage:
| Symbol | Description | Units |
| a | General purpose constant | |
| a | Acceleration | m/s2 |
| a | Bühlmann constant. | |
| b | General purpose constant | |
| b | Bühlmann constant. | |
| c | Specific heat, per kg | J/(kg K) |
| C | Specific heat, per mole | J/(mole K) |
| c | General purpose constant | |
| d | Depth | m |
| E | Energy | Joule = Nm |
| Ep | Potential energy | Joule = Nm |
| Ek | Kinetic energy | Joule = Nm |
| F | Force | N |
| FW | Force due to gravity a.k.a weight | N |
| FA | Archimedes Force | N |
| g | Constant of gravity, 9.8 N/s2 | N/s2 |
| γ | Surface tension associated with a gas-liquid surface | N/m |
| γc | 'Crumbling compression': large-scale situation value of Γ | N/m |
| Γ | Skin tension associated with the hydrophobic surfactant layer surrounding the nucleus. | N/m |
| h | Height | m |
| k | Exponential constant k = ln(2)/τ specifying the on- and offgassing rate of a tissue compartment. | 1/min |
| k | Bolzman constant. | |
| m | Mass. | kg |
| μ | Atomic weight | Dimensonless |
| M | M value. | |
| M0 | ||
| ΔM | ||
| P | Pressure | bar |
| Palv | Alveolar partial pressure of the inert gas. This is the pressure in the alveoli in the lungs. | bar |
| Pamb | Ambient pressure due to atmospheric pressure and depth | bar |
| Pamb_sea_level | Ambient pressure at sea level or atmospheric pressure. | bar |
| Pm | Ambient pressure defining the VPM rudimentary pressure schedule. | bar |
| Ps | Ambient pressure defining the VPM rudimentary pressure schedule. The sample is saturated at this pressure. | |
| Pss | Supersaturation gradient defined as the difference between the tissue tension and the ambient pressure Pt-Pamb. | bar |
| Pssmin | Maximum allowed supersaturation gradient (Pt-Pamb)max. This is the supersaturation gradient resulting in all nuclei with an initial radius larger than r0min grow into a bubble. Any gradient smaller than this value will result in less bubbles. | bar |
| Pssnew | New maximum allowed supersaturation gradient. Replaces Pssmin, resulting in a larger supersaturations and shorter deco times. | bar |
| Q | Inert gas fraction in the gas mixture | |
| Q | Heat | Joule |
| R | Linear rate of change of the alveolar partial pressure due to (linear) depth change. | bar/min |
| Ramb | Linear rate of change of the ambient pressure due to (linear) depth change. | bar/min |
| RQ | Respiratory coefficient | |
| S | Displacement, way length | m |
| t | Time | min |
| τ | Halftime. Dependant on the tissue compartment and the inert gas | min |
| τR | Regeneration time constant of a nucleus. | min |
| v | Velocity | m/s |
| W | Work | Joule = Nm |
Often pressure is expressed in meter-sea-water (msw) or feet-sea-water (fsw) in decompression theory. It has the advantage that the increase in ambient pressure due to depth is equal to depth. However, msw and fsw are not SI units. Furthermore, if being precise, the pressure of 1 meter-sea-water varies with temperature and amount of dissoved salt! So on this homepage I have used the bar as pressure unit. Actually Pascal is the SI unit, however the bar is more convenient. Following conversion factors can be used:
| Unit | Abbreviation | In bar |
| meter sea water | msw | 0.1 bar |
| foot sea water | fsw | ? bar |
| Pound per square inch | psi | ? bar |
| millimeter Hg | mmHg, torr | 0.01333 bar |
| Atmoshpere | atm | 1.01325 bar |
| Pascal | Pa | 10-5 bar |
Other conversions to SI used on this homepage are:
| Force | Dyne | dyn | 10-5 Newton |
| Length | Foot | ft | ? meter |
