I was recently working on a thermometer control and decided to write a temperature class to go along with it.  What I found interesting is that there are temperature systems that I had never even heard of let alone used (namely Reaumer and Rankine).  I'm from Canada and I've heard of some pretty nasty temperatures, but these were still a suprise to me. :-)  Anyway I wrote the class in C# and thought others might find some use in it.   Here it is:

using System;

namespace ThermometerDemo
{
    /// <summary>
    /// Summary description for Temperature.
    /// </summary>
    public class Temperature
    {
        public enum SystemOfMeasure { Fahrenheit = 0, Celsius, Kelvin, RanKine, Reaumer };

        private SystemOfMeasure _systemOfMeasure;
        public SystemOfMeasure Scale
        {
            get { return _systemOfMeasure; }
            set { _systemOfMeasure = value; }
        }

        private double _temperatureKelvin;
        public double Value
        {
            get { return Temperature.Convert( _temperatureKelvin, SystemOfMeasure.Kelvin, _systemOfMeasure ); }
            set { this._temperatureKelvin = Temperature.Convert( value, _systemOfMeasure , SystemOfMeasure.Kelvin ); }
        }

        public double AbsoluteZero
        {
            get { return Temperature.Convert( 0F, SystemOfMeasure.Kelvin, _systemOfMeasure ); }
        }

        #region Construction

        public Temperature() : this( SystemOfMeasure.Kelvin, 298.15F )
        {
            // SI temperature at standard state in Kelvin.
        }

        public Temperature( SystemOfMeasure systemOfMeasure ) : this( systemOfMeasure, 298.15F )
        {
            // SI temperature at standard state.
        }

        public Temperature( double temperature ) : this( SystemOfMeasure.Kelvin, temperature )
        {
        }

        public Temperature( SystemOfMeasure systemOfMeasure, double temperature )
        {
            _systemOfMeasure = systemOfMeasure;
            Value = temperature;
        }

        #endregion Construction

        # region Public Methods

        public static double Convert( double temperature, SystemOfMeasure originSystem, SystemOfMeasure targetSystem )
        {
            // Convert to Kelvin.
            double temperatureKelvin;
            switch( originSystem )
            {
                case SystemOfMeasure.Fahrenheit:
                    temperatureKelvin = ( 5F / 9F ) * ( temperature - 32 ) + 273.15F;
                    break;

                case SystemOfMeasure.Celsius:
                    temperatureKelvin = temperature + 273.15F;
                    break;

                case SystemOfMeasure.Kelvin:
                    temperatureKelvin = temperature;
                    break;

                case SystemOfMeasure.Reaumer:
                    temperatureKelvin = ( 5F / 9F ) * temperature + 273.15F;
                    break;

                case SystemOfMeasure.RanKine:
                    temperatureKelvin = temperature / 1.8F;
                    break;

                default:
                    throw new ArgumentOutOfRangeException( "originSystem", originSystem, "Unsupported origin system of measure");
            }

            // Convert to the new system.
            double resultTemperature;
            switch( targetSystem )
            {
                case SystemOfMeasure.Fahrenheit:
                    resultTemperature = 32F + ( 1.8F ) * ( temperatureKelvin - 273.15F );
                    break;

                case SystemOfMeasure.Celsius:
                    resultTemperature = temperatureKelvin - 273.15F;
                    break;

                case SystemOfMeasure.Kelvin:
                    resultTemperature = temperatureKelvin;
                    break;

                case SystemOfMeasure.Reaumer:
                    resultTemperature = ( 1.8F ) * ( temperatureKelvin - 273.15F );
                    break;

                case SystemOfMeasure.RanKine:
                    resultTemperature = temperatureKelvin * 1.8F;
                    break;

                default:
                    throw new ArgumentOutOfRangeException( "originSystem", originSystem, "Unsupported target system of measure");
            }

            return resultTemperature;
        }

        public static string GetUnitAbbreviation( SystemOfMeasure systemOfMeasure )
        {
            switch( systemOfMeasure )
            {
                case SystemOfMeasure.Fahrenheit:
                    return "°F";

                case SystemOfMeasure.Celsius:
                    return "°C";

                case SystemOfMeasure.Kelvin:
                    return "K";

                case SystemOfMeasure.Reaumer:
                    return "°Re";

                case SystemOfMeasure.RanKine:
                    return "°Ra";

                default:
                    throw new ArgumentOutOfRangeException( "systemOfMeasure", systemOfMeasure, "Unsupported system of measure");
            }
        }

        #endregion Public Methods
    }
}

eHowitzer