(* :Title: SIUnits *)

(* :Author: Wolfram Research *)

(* :Summary: 
This package introduces base SI and derived SI units.
(SI stands for the International System of units).
*)

(* :Package Version: 1.1 *)

(* :Copyright: Copyright 1990-1999, Wolfram Research, Inc. *)

(* :Context: Miscellaneous`SIUnits` *)

(* :History:
	ECM (Wolfram Research), November 1990
	Revised April 1997 *)

(* :Keywords: *)

(* :Source:
	CRC Handbook of Chemistry & Physics, 69th edition, 1988-1989 *)

(* :Warning: Makes use of the system symbols
         Second and Newton. *)

(* :Mathematica Version: 3.0 *)

(* :Limitation: None. *)

(* :Discussion: *)

BeginPackage["Miscellaneous`SIUnits`"]

(** fundamental SI units usage **)

Map[(Evaluate[#[[1]]]::"usage" =
   StringJoin[ToString[#[[1]]], " is the fundamental SI unit of ", #[[2]]])&,
	{{Meter,"length."},{Kilogram,"mass."},
	 {Ampere,"electric current."},{Kelvin,"thermodynamic temperature."},
	 {Mole,"amount of substance."},
	 {Candela,"luminous intensity (candlepower)."}}
	]

$NewMessage[ Second, "usage"]; (* reset usage message of Second to the
					System` usage *)
Second::usage = StringJoin[ Second::usage,
	 "   It is also the fundamental SI unit of time."]
$NewMessage[ Newton, "usage"]; (* reset usage message of Newton to the
					System` usage *)
Newton::usage = StringJoin[ Newton::usage,
	 "   It is also the derived SI unit of force."]

(** derived SI units usage **)

Map[(Evaluate[#[[1]]]::"usage" =
	StringJoin[ToString[#[[1]]], " is the derived SI unit of ", #[[2]]])&,
	{{Pascal,"pressure."},{Joule,"energy."},
	{Watt,"power."},{Coulomb,"electric charge."},
	{Volt,"electric potential difference."},{Ohm,"electric resistance."},
	{Siemens,"electric conductance."},{Farad,"electric capacitance."},
	{Weber,"magnetic flux."},{Henry,"inductance."},
	{Tesla,"magnetic flux density."},{Lumen,"luminous flux."},
	{Lux,"illumination (illuminance)."},{Hertz,"frequency."},
	{Becquerel,"radioactivity."},{Gray,"absorbed dose of radiation."}}
	]
Amp::usage =
	"Amp, short for Ampere, is the fundamental SI unit of electric current."

EndPackage[]
