ProfitPress Mega CDROM2 …eeware (MSDOS)(1992)(Eng)/ProfitPress-MegaCDROM2.B6I/MISC/MATH/CONVPROG.ZIP/CONVS.INF

Text File | 1990-10-07 | 14.7 KB | 290 lines

.1
                     Metric and imperial conversions
This item  is one  of the  eighteen available  on  the  Applied  Environmetrics
Hydrological Tables.  The hydrological  tables are  the third  in the computer-
based series  of tables  produced by  Applied Environmetrics.  All of the other
items in  the series  accept the  entry of variables in a variety of metric and
imperial units,  but only  present the results in SI units. This procedure will
suit scientists, but it can be inconvenient to practitioners - especially those
in the  United States  - who do not normally use the SI system. This item is to
assist in  the conversion  of units  of most of the output tabulations from the
hydrological tables.

There are  three systems  of units in common use. These are the US system (many
units of  which are  the same  as the  old British Imperial system), the metric
system and  the SI  system. This  item is to assist in converting between these
three systems.This item  recognises units in either of the above three systems,
and in many cases  will  recognize  mixtures  of  the  three.  Altogether  2380
units are recognised. Conversion takes place to more standard units. Altogether
to 174 units.
.2
The item  begins by  presenting a  Table of  Contents from which you choose the
variable of  interest. The fourteen choices are: temperature, pressure, length,
area, volume,  speed, flow  (i.e. discharge)  mass,  mass  transport,  density,
energy, power,  energy flux  (i.e. irradiance), and specific heat capacity. The
Table of  Contents also  lists a  selection of the units that are available for
conversion. Consult  this documentation  for a  complete list and for advice on
acceptable entries.

Remember that the table exists for conversion between presently used systems of
units. Because imperial fluid measures are no longer used the gallon, quart and
fluid ounce  all refer  to US  measures. Similarly,  the ton  as a unit of mass
refers to the short (2000 avoirdupois pound) ton used in the US, rather than to
the old  imperial long  ton. The  metric ton  (2000 kg.)  is always  called the
tonne.

Before discussing each tabulation in detail, there is a brief discussion of the
systems of units.
.3
The SI system (BIPM, 1981; UNESCO, 1985)
The SI  system of  units is  the modern  version of the metric system which has
been universally adopted by scientists. Details of the system are given in BIPM
(1981) and  numerous documents  published by national authorities. In preparing
the series of environmental tables I have relied heavily on UNESCO (1985). Only
a brief summary is given here.

The SI  system is  an extension of the MKS system, where the acronym stands for
metre, kilogram,  second.   These are  the base units for length, mass and time
respectively and have the symbols m, kg and s. Other quantities and their units
are built  from the  base quantities  and units. These are called derived units
and many  have received  a special  name.   For example, energy expressed in SI
base units  has units  m^2.kg.s^-2 which has been given the name joule, and the
abbreviation J.
.4
The metric system
The idea  of the  metric system  (also used in SI) is that prefixes are used to
form decimal  multiples and  submultiples of  units. The  most common  ones are
mega-(M) for  10^6, kilo-(k)  for 10^3,  hecto-(h) for 100, centi-(c) for 0.01,
milli-(m) for 10^-2 and micro-(u) for 10^-6.
Note that the proper abbreviation for micro is the greek mu. The closest letter
on the  keyboard, is u, which, if entered as a metric prefix is taken as micro.
These conversion  tables will  recognise all of these prefixes as well as deci-
(d) for 0.1

The SI  system encourages  only a restricted set of units. Thus the hectare - a
perfectly acceptable metric unit - is strongly discouraged under the SI system.
Firstly the  are (which  is 100  square metres)  is not  a recognised  SI unit.
Secondly, the  SI system  prefers quantities  in multiple of 10^3. Thirdly, the
symbol ha,  which is  normally used  for hectares, is actually hectoannum (i.e.
100 years) in the SI system.
.5
The United States system
The US  system of weights and measures is based on the British Imperial system.
The units of mass, length and time are the pound, yard and second respectively.
These are  multiplied or subdivided into units which have different names - and
are always based on non-decimal multiples.

Representing units
All of  the entries  in this item require you to give a value and its units and
conversion is  based on  the units that you entered. You will be given examples
of the preferred form for the units, but the program will try hard to interpret
your entry.  For example,  J/(s ft^2) is preferred but J/(ft^2 s), J ft^-2 s^-1
and J s^-1 ft^-2 are all understood.

The program  will try to interpret some incorrect entries. Thus an entry of 6MM
as a  length will  assume that  entry was  inadvertently in  capitals and use 6
millimetres but 6Mm will be taken as 6 megametres.
.6
Temperature
The unit  of thermodynamic  temperature is  an SI  base unit.  It has  the name
kelvin and  the symbol  K. This  unit and  name are  also used  to  express  an
interval or  difference of temperature.  The Celsius temperature (t) is defined
in terms of the thermodynamic temperature (T) by
t = T - 273.15
The unit  "degree Celsius"  equals the  unit "kelvin"  but expresses  a Celsius
temperature.   Because of  the absence  of a degree sign on computer keyboards,
the symbol C is used.

The US system of temperature is based on the Fahrenheit as a unit for which the
symbol F  is used.  A Fahrenheit  temperature (F)  is related  to  the  Celsius
temperature by
     F - 32 = 1.8 t
The International  Committee for  Weights and  Measures at  its September  1989
meeting approved  the use  of ITS-90:  The International  Temperature Scale  of
1990. In  this scale  the triple  point of  water is at 273.16K but the boiling
point of water at 1013.25hPa is 99.974C.
.7
Pressure
The following are converted: (abbreviations in brackets)

bar [ba] - and all its metric prefixes
Pascal [Pa] - and all its metric prefixes.
Mass per  area -  any acceptable  mass (imperial  or  metric)  divided  by  any
acceptable area (imperial or metric)
The mass is taken as a force
Length Hg- The height of a mercury column [e.g. 760mmHg or 29.92inHg]
Length H2O - The height of a water column [e.g. 9ftH2O or 3mH2O]
barye [barye] - must be entered like this
dyne per area - e.g 5dyne/cm^2. Do not abbreviate dyne
newton [N] per area - e.g. 5N/m^2 or 5N m^-2

Notes:
See the appropriate pages for acceptable mass, length and area entries.
Any unidentified length is treated as the height of a mercury colum.
.8
Pressure conversions
The conversions are given in the following units:
bar, decibar,  kPa, millibar  (i.e. hPa), Pascal (i.e. N/m^2), kg/cm^2, kg/m^2,
mmHg (i.e.  Torr), inch  Hg, psi  (i.e. pounds  per square  inch), atmospheres,
barye which is the same as dyne/cm^2, cmH2O, ftH2O, ton/ft^2, N/cm^2.

At the  first prompt  for a  value, pressing  the Enter  key on its own will be
taken as  1 atmosphere (1013.25 hPa). At subsequent prompts, pressing the Enter
key on its own indicates that the tabulation is complete.

The length  conversions (water  and mercury)  are based on a temperature of 0C.
The  mass   conversions  use   the  conventional  standard  value  for  gravity
acceleration of
g = 9.80665
.9
Length
The following lengths are converted:

The metre and any of its seven common prefixes. Thus Mm, km, hm, m, dm, cm, mm,
um are all recognised units.

Imperial  units   of  inch   [in],  foot[ft],  yard[yd],  chain[ch],  mile[mi].
Combinations of imperial units are accepted so that 1ft12in is treated the same
as 2ft.
The abbreviations 1'12" can also be used.

The United  States uses  two definitions  of the  yard.    For  industrial  and
scientific purposes  the American  Standards Association  has adopted  the yard
defined as 0.9144 m exactly. This is the one used in these tables. However, the
US yard, which is primarily used for land-surveying is defined as 3600/3937 m.
.10
Area
You may  enter the square of any of the length units except for the chain, plus
units of  acres [ac] where an acre is 10 square chains. Because the metric unit
of area  is the  are [a],  which is  100m^2, metric  prefixes to  this are also
recognised. Thus 6ac is recognised as 6 acres but 6ca is 6 centi-ares.

The abbreviation  for powers  follows that of Basic. Thus m^2 represents square
metres. However  sq. is also recognised for square so that an alternate form of
1m^2 is 1sq. m

In the SI system a combination of prefix and symbol for a unit is regarded as a
single symbol  which may  be raised  to a  power without  brackets. Thus 1 cm^2
always means  (0.01 m)^2  and never  0.01 m^2.  Because 1 m^2 is a centare [ca]
this last  unit could be written as 0.01 ca.  Remember that the are [a], though
a metric unit, is not an SI unit.

Conversions are  given in  square inches,  feet, yards, miles, m^2, mm^2, cm^2,
km^2, acres and hectares.
.11
Volume
You may  enter the  cube of  any of  the length  units except  for the chain as
powers (e.g.  2.4m^3) or  using cu. for cubic (e.g. 2.4cu. m, 1in^3). There are
two other  metric (but  not SI) units of volume. The litre [l], which is 1dm^3,
and the  stere [s],  which is  1m^3.   Both of  these, and  their common metric
prefixes are  accepted. In addition, the common (though incorrect) abbreviation
cc is recognised as cm^3.

You may  also enter  US liquid  measures as ounces [oz], quarts [qt] or gallons
[gal] or any combination of these three. For example, 1gal3qt2oz.

Finally, this  item recognises  three special hydrological units. The acre-foot
[af] (an  area of  1 acre  covered with  a foot  of water), the second-foot day
[sfd] which  is the volume of water in a flow of one second-foot (i.e. 1ft^3/s)
over one day. A metric (non-SI) version of this is the cumec-day [cmd] which is
the volume of water in a flow of one cumec (i.e. 1m^3/s) over one day.

Conversions are  given in  m^3, ft^3,  in^3, gal,  qt, oz,  af, sfd, cmd, cm^3,
litres and Ml (megalitres).
.12
Speed
Any length  unit per  second [s],  minute [min],  hour [h] or day [d] expressed
using either  powers, or  with a slash is acceptable. E.g. 6m s^-1, 8mi/h. Also
you may enter knots without abbreviation.

The knot  is one  nautical mile  per hour and has been universally agreed to as
1852 metres  per hour.  If you  need to  convert to  or from  length  units  of
nautical miles then it can be done using this table.

Conversions are  given as  knots, then  as length  per time  where  the  output
lengths are m, km, in, ft, y, mi and the times are s, min, h, d.

Flow
Accepts any  volume unit  per second [s], minute [min], hour [h] or day [d] and
converts it  to outputs  of volume  per time  where the  volumes are m^3, ft^3,
in^3, gal, qt, oz, af, sfd, cmd, cm^3, l, Ml and the times are s, min, h, d.

.13
Mass
The SI  unit of  mass is  the kilogram [kg].  Because this already has a metric
prefix, and  the SI  system does not allow double prefixes, all metric units of
mass add  prefixes to the gram [g].  The common ones are all acceptable, as are
the metric  ton [tonne],  and the  avoirdupois ounce  [oz], pound  [lb] and ton
[ton] - where ton is taken as the short ton of 2000lb.

Conversion is to kg, lb, oz, ton, tonne, g.

Mass transport
Accepts any  mass unit  per second  [s], minute  [min], hour [h] or day [d] and
converts it  to outputs  of mass per time where the conversion of mass units is
as given above and all four time units are used.

Density
Accepts any  mass per  volume, where the acceptable mass units and volume units
are as  given above.  There are  thus 420  acceptable units.  Conversion is  to
kg/m^3, g/cm^3 and lb/ft^3.
.14
Energy
The SI  unit of  energy is the joule [J] and its use has rendered obsolete both
the erg  and the  calorie. One  problem with  the calorie was that there were a
number of  different definitions  (and hence  values) for it.  These conversion
tables use  the International Table calorie (IT calorie) of 4.18684 J. A fourth
metric unit of energy is recognised by this item. The kilowatt-hour [kWh].

Imperial units  of energy  that are accepted are the British thermal unit [BTU]
and the foot-pound [ft-lb]. Conversion then takes place between these units and
the four metric units.

Power
The SI  unit is  the watt  [W] which  is the  power dissipated by one joule per
second. The  imperial unit  is the  horsepower [HP] which is 550 ft-lb/s.  This
item accepts  a power  in either of these units or as an energy per second [s],
minute [min], hour [h] or day [d] and converts between them all.

.15
Energy flux
This is  the energy  per unit area per unit time. In the SI system it has units
of W/m^2.  This item  recognises any  acceptable power divided by an acceptable
area, or  an energy  divided by  an area  and a time. Use the form J/(m^2 s) or
J/(s m^2).   It  is incorrect to use double slashes as in J/m^2/s and this will
not be recognised.

Conversion is to W/m2, HP/ft^2, mW/m^2, W/ft^2, W/in^2, and to J/m^2, BTU/ft^2,
BTU/in^2, cal/m^2, cal/cm^2 per second [s], minute [min], hour [h] or day [d] .


Specific heat capacity
Both the  calorie and  the BTU  are defined  in terms  of the  amount  of  heat
required to increase the temperature of water. The relation

     1 BTU/(lb F)  = 1 IT cal/(g C)

has been  used for conversion. This item recognises any acceptable energy, mass
unit, or  temperature unit  and converts  to J/(kg  K), BTU/(lb  F), erg/(g K),
cal/(g K), ft-lb/(lb F) and cal/(kg K).
.16
References
BIPM (Bureau  International des  Poids et  Mesures), Le  Systeme  International
d'Unites (SI), 4th edition, 1981.
(An english  translation was  prepared jointly  by  the  UK  National  Physical
Laboratory and the US National Bureau of Standards).
UNESCO, The International System of Units (SI) in Oceanography, Technical paper
in marine science No. 45, (IAPSO publication No. 32), Unesco, Paris, 1985.
      ---------------------------------------------------------------
                                   REMINDER
This program is being distributed as shareware to publicise the Applied
Environmetrics Hydrological Tables.  It forms one of the eighteen items that
make up these tables.  Applied Environmetrics publishes computer-based
environmental and scientific tables and is looking for authors.
For further information write to Applied Environmetrics
118 Gordon St.                                             PO Box 241
Balwyn, Vic. 3103                                          Roslyn, WA
Australia                                                  USA  98941-0241
Phone [phone]                                         Ph: [phone]