3. Predefined Quantities¶
The module quantity.predefined provides definitions of commonly used quantities and units.
3.1. Length¶
Reference unit: Metre (‘m’)
Predefined units:
| Symbol | Name | Definition | Equivalent in ‘m’ |
|---|---|---|---|
| µm | Micrometre | 0.000001·m | 0.000001 |
| mm | Millimetre | 0.001·m | 0.001 |
| cm | Centimetre | 0.01·m | 0.01 |
| in | Inch | 2.54·cm | 0.0254 |
| dm | Decimetre | 0.1·m | 0.1 |
| ft | Foot | 12·in | 0.3048 |
| yd | Yard | 3·ft | 0.9144 |
| ch | Chain | 22·yd | 20.1168 |
| fur | Furlog | 10·ch | 201.1680 |
| km | Kilometre | 1000·m | 1000 |
| mi | Mile | 8·fur | 1609.3440 |
3.2. Mass¶
Reference unit: Kilogram (‘kg’)
Predefined units:
| Symbol | Name | Definition | Equivalent in ‘kg’ |
|---|---|---|---|
| mg | Milligram | 0.000001·kg | 0.000001 |
| ct | Carat | 0.2·g | 0.0002 |
| g | Gram | 0.001·kg | 0.001 |
| oz | Ounce | 0.0625·lb | 0.028349523125 |
| lb | Pound | 0.45359237·kg | 0.45359237 |
| st | Stone | 14·lb | 6.35029318 |
| t | Tonne | 1000·kg | 1000 |
3.3. Duration¶
Reference unit: Second (‘s’)
Predefined units:
| Symbol | Name | Definition | Equivalent in ‘s’ |
|---|---|---|---|
| min | Minute | 60·s | 60 |
| h | Hour | 60·min | 3600 |
| d | Day | 24·h | 86400 |
3.4. Area¶
Definition: Length²
Reference unit: Square Metre (‘m²’)
Predefined units:
| Symbol | Name | Definition | Equivalent in ‘m²’ |
|---|---|---|---|
| mm² | Square Millimetre | mm² | 0.000001 |
| cm² | Square Centimetre | cm² | 0.0001 |
| in² | Square Inch | in² | 0.00064516 |
| dm² | Square Decimetre | dm² | 0.01 |
| ft² | Square Foot | ft² | 0.09290304 |
| yd² | Square Yard | yd² | 0.83612736 |
| a | Are | 100·m² | 100 |
| ac | Acre | 4840·yd² | 4046.85642240 |
| ha | Hectare | 100·a | 10000 |
| km² | Square Kilometre | km² | 1000000 |
| mi² | Square Mile | mi² | 2589988.11033600 |
3.5. Volume¶
Definition: Length³
Reference unit: Cubic Metre (‘m³’)
Predefined units:
| Symbol | Name | Definition | Equivalent in ‘m³’ |
|---|---|---|---|
| mm³ | Cubic Millimetre | mm³ | 0.000000001 |
| ml | Millilitre | 0.001·l | 0.000001 |
| cm³ | Cubic Centimetre | cm³ | 0.000001 |
| cl | Centilitre | 0.01·l | 0.00001 |
| in³ | Cubic Inch | in³ | 0.000016387064 |
| dl | Decilitre | 0.1·l | 0.0001 |
| l | Litre | 0.001·m³ | 0.001 |
| dm³ | Cubic Decimetre | dm³ | 0.001 |
| ft³ | Cubic Foot | ft³ | 0.028316846592 |
| yd³ | Cubic Yard | yd³ | 0.764554857984 |
| km³ | Cubic Kilometre | km³ | 1000000000 |
3.6. Velocity¶
Definition: Length/Duration
Reference unit: Metre per Second (‘m/s’)
Predefined units:
| Symbol | Name | Definition | Equivalent in ‘m/s’ |
|---|---|---|---|
| km/h | Kilometre per hour | km/h | 5/18 |
| ft/s | Foot per Second | ft/s | 0.3048 |
| mph | Mile per Hour | mi/h | 0.44704 |
3.7. Acceleration¶
Definition: Length/Duration²
Reference unit: Metre per Second squared (‘m/s²’)
Predefined units:
| Symbol | Name | Definition | Equivalent in ‘m/s²’ |
|---|---|---|---|
| mps² | Mile per Second squared | mi/s² | 1609.3440 |
3.8. Force¶
Definition: Mass·Acceleration
Reference unit: Newton (‘N’)
Predefined units:
| Symbol | Name | Definition | Equivalent in ‘N’ |
|---|---|---|---|
| J/m | Joule per Metre | J/m | 1 |
3.9. Energy¶
Definition: Length·Force
Reference unit: Joule (‘J’)
Predefined units:
| Symbol | Name | Definition | Equivalent in ‘J’ |
|---|---|---|---|
| Ws | Watt Second | s·W | 1 |
| kWh | Kilowatt Hour | h·kW | 3600000 |
3.10. Power¶
Definition: Energy/Duration
Reference unit: Watt (‘W’)
Predefined units:
| Symbol | Name | Definition | Equivalent in ‘W’ |
|---|---|---|---|
| mW | Milliwatt | 0.001·W | 0.001 |
| kW | Kilowatt | 1000·W | 1000 |
| MW | Megawatt | 1000000·W | 1000000 |
| GW | Gigawatt | 1000000000·W | 1000000000 |
| TW | Terawatt | 1000000000000·W | 1000000000000 |
3.11. DataVolume¶
Reference unit: Byte (‘B’)
Predefined units:
| Symbol | Name | Definition | Equivalent in ‘B’ |
|---|---|---|---|
| b | Bit | 1·B/8 | 0.125 |
| kb | Kilobit | 1000·b | 125 |
| Kib | Kibibit | 1024·b | 128 |
| kB | Kilobyte | 1000·B | 1000 |
| KiB | Kibibyte | 1024·B | 1024 |
| Mb | Megabit | 1000000·b | 125000 |
| Mib | Mebibit | 1048576·b | 131072 |
| MB | Megabyte | 1000000·B | 1000000 |
| MiB | Mebibyte | 1048576·B | 1048576 |
| Gb | Gigabit | 1000000000·b | 125000000 |
| Gib | Gibibit | 1073741824·b | 134217728 |
| GB | Gigabyte | 1000000000·B | 1000000000 |
| GiB | Gibibyte | 1073741824·B | 1073741824 |
| Tb | Terabit | 1000000000000·b | 125000000000 |
| Tib | Tebibit | 1099511627776·b | 137438953472 |
| TB | Terabyte | 1000000000000·B | 1000000000000 |
| TiB | Tebibyte | 1099511627776·B | 1099511627776 |
3.12. DataThroughput¶
Definition: DataVolume/Duration
Reference unit: Byte per Second (‘B/s’)
Predefined units:
| Symbol | Name | Definition | Equivalent in ‘B/s’ |
|---|---|---|---|
| b/s | Bit per Second | b/s | 0.125 |
| kb/s | Kilobit per Second | 1000·b/s | 125 |
| Kib/s | Kibibit per Second | 1024·b/s | 128 |
| kB/s | Kilobyte per Second | 1000·B/s | 1000 |
| KiB/s | Kibibyte per Second | 1024·B/s | 1024 |
| Mb/s | Megabit per Second | 1000000·b/s | 125000 |
| Mib/s | Mebibit per Second | 1048576·b/s | 131072 |
| MB/s | Megabyte per Second | 1000000·B/s | 1000000 |
| MiB/s | Mebibyte per Second | 1048576·B/s | 1048576 |
| Gb/s | Gigabit per Second | 1000000000·b/s | 125000000 |
| Gib/s | Gibibit per Second | 1073741824·b/s | 134217728 |
| GB/s | Gigabyte per Second | 1000000000·B/s | 1000000000 |
| GiB/s | Gibibyte per Second | 1073741824·B/s | 1073741824 |
| Tb/s | Terabit per Second | 1000000000000·b/s | 125000000000 |
| Tib/s | Tebibit per Second | 1099511627776·b/s | 137438953472 |
| TB/s | Terabyte per Second | 1000000000000·B/s | 1000000000000 |
| TiB/s | Tebibyte per Second | 1099511627776·B/s | 1099511627776 |
3.13. Temperature¶
Predefined units:
| Symbol | Name | Equivalents |
|---|---|---|
| °C | Degree Celsius | 0 °C = 32 °F = 273,25 K |
| °F | Degree Fahrenheit | 0 °F ≅ -17.778 °C ≅ 255.372 K |
| K | Kelvin | 0 K = -273,25 °C = -459.67 °F |
Temperature units are converted using the following formulas:
| from \ to | Celsius | Fahrenheit | Kelvin |
|---|---|---|---|
| Celsius | [°F] = [°C] * 9/5 + 32 | [K] = [°C] + 273.15 | |
| Fahrenheit | [°C] = ([°F] - 32) * 5/9 | [K] = ([°F] + 459.67) * 5/9 | |
| Kelvin | [°C] = [K] - 273.15 | [°F] = [K] * 9/5 - 459.67 |