Size and Temperature conversions
From version 1.5.4 of Plant Base, options are provided to work in Imperial
feet and inches and also with the Fahrenheit temperature scale.
Operation
These two features can be enabled from the Program Config Options,
using the checkboxes under the "Misc" tab.
The default options are Metric and Celsius, which is still how
the underlying data is stored. Enabling the checkboxes does not
alter the data, they cause the Plant Master and Plant Selector
screens to convert it for display and/or entry.
The previously existing option to show conversions as mouse-over
tips is still available. It has been changed so that it displays
in the relevant measurement system.
It is possible to enter more than 12 inches, this is valid and
will be displayed as feet and inches (e.g. 30ins = 2ft 6ins).
Dimensions over 1 foot are rounded to the nearest inch, below
1 foot will be shown as decimal inches.
Considerations
Imperial or Fahrenheit conversions will often produce "irregular"
numbers. For example, 1.8 metres is often used as the equivalent
of 6 feet, but in fact converting from 1.8 metres gives 5 feet
11 inches. The effect is small, but an allowance for this may
be needed when searching for plants.
Minimum temperature values are held in the database as whole
degrees Celsius. When working in Fahrenheit the values will be
slightly adjusted to give the equivalent of the nearest whole
degree Celsius (e.g. entering 28°F will give 28.4°F, the
equivalent of -2°C).
When entering or editing plant data, frequently switching between
measurement system is likely to cause small rounding discrepancies.
It is best to choose a measurement system and then stick with
it as far as possible.
Background
The Imperial System was formally defined in 1824, based on various
measurement units that had a very long history of common usage.
It is essentially the same as U.S. customary units or English
units. It was generally used by British derived countries and
is still popular in those areas. Notably it remains the official
system in the USA
The Metric system, now properly referred to as SI (Système
international d'unités), was defined in France in 1791
and later extensively adopted elsewhere. It is now the official
system used in the European Union and became the legal system
for the UK in 1995, although implementation had begun much earlier.
1 inch = 25.4 millimetres
1 foot = 0.3048 metres
1 metre = 39.37 inches = 3.2708 feet
The Fahrenheit temperature scale is named after the German physicist
Gabriel Fahrenheit, who proposed it in 1724.
Celsius was named in honour of the Swedish astronomer Anders
Celsius, who first proposed the principles of this system in 1742.
1 degree in Celsius = 1.8 degrees in Fahrenheit
Freezing point of water = 0°C = 32°F
Boiling point of water = 100°C = 212°F
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