On 2010/06/12, at 01:14 , Phil Hall wrote:
These remarks are prompted by the "Oil spill" thread which lead to a
discussion on units of volume.
The litre (or liter of you prefer) has, IMHO, a lot going for it as
a general purpose unit for most ranges. Its main advantage is the
avoidance of the superscripted 3 for plain text messaging. It is
also easily converted to cubic metres when that is required (just
divide by 1000). I have to say I don't like the dam³ that has been
suggested. I don't see why the megalitre or ML won't do just as well.
We then have:
1 m³ = 1 kL
1 dam³ = 1 ML
1 hm³ = 1 GL
1 km³ = 1 TL
Simple yes?
Dear Phil,
Having lived in a society where most of us very successfully use this
small set of units for all of our everyday tasks:
1000 millilitres = 1 litre
1000 L = 1 cubic metre
100 grams = 1 kilogram
1000 kilograms = 1 tonne
1000 millimetres = 1 metre
1000 metres = 1 kilometre
I find it hard to agree that it would be a good idea to introduce the
dam³, the hm³, and the km³ to Australians for everyday use.
In the specialist area of farming, and especially of irrigation
farming, the metric system units, kilolitre, megalitre and gigalitre,
have served us well. This is especially true for farm water
calculations.
You know the basic rule: one millimetre of rain on a 1 square metre
surface supplies a litre of water. Farmers expand this to 1 millimetre
of rain on one hectare provides 10 000 litres (10 kL) of water.
It follows that (say) 200 millimetres of irrigation water needed for a
vegetable crop on one hectare of land will need 3 000 000 litres of
water (300 millimetres x 10 000 litres); which would be ordered from
the irrigation water supplier as 3 megalitres.
By the way, you might not have seen this curious unit used by
Australian farmers and graziers: kilograms per millimetre-hectare (kg/
mm.ha). This is used to compare two pieces of farming land that have
different rainfall. As an example for cattle grazing a property might
produce 800 kilograms of beef from each hectare from a farm where 540
millimetres of rain falls in a particular year.
Cheers,
Pat Naughtin
Author of the ebook, Metrication Leaders Guide, see
http://metricationmatters.com/MetricationLeadersGuideInfo.html
Hear Pat speak at: http://www.youtube.com/watch?v=_lshRAPvPZY
PO Box 305 Belmont 3216,
Geelong, Australia
Phone: 61 3 5241 2008
Metric system consultant, writer, and speaker, Pat Naughtin, has
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modern metric system smoothly, quickly, and so economically that they
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