Dealing with Temperature Units

You must take special care when using temperature units in GoldSim, since unlike other unit categories A category of units defined by a name (e.g., Area) and a specific set of dimensions (Length^2)., different temperature units are related not just through a conversion factor, but an offset. That is, the zero-values for Celsius (C) and Fahrenheit (F) temperatures are not absolute (i.e., whereas 0 m = 0 ft; it is not true the 0 F = 0 C).

To handle this properly, when you deal with temperatures in GoldSim, you have to be clear whether you are actually specifying a temperature (C, F, or K) or degrees of a particular temperature scale (Cdeg, Fdeg, or K). Temperature and degrees of temperature are treated the same in K, so there is no reason to differentiate when expressing temperature in K.

Use of these units is best explained through examples:

• If the temperature yesterday was 20C, and today is 5C warmer, you should calculate today’s temperature as "20 C + 5 Cdeg". If you mistakenly entered "20 C + 5 C", it would be interpreted as “293.15 K + 278.15 K” which equals 571.3 K or 298.15C!
• Similarly, when defining a temperature as a Stochastic, you must be careful. For example, a normal distribution for a temperature defined in Celsius degrees as 20 +/- 5 should be specified as Mean: 20 C, SD: 5 Cdeg. Specifying it incorrectly as Mean: 20 C, SD: 5 C would result in a very large standard deviation!
• If you use a compound unit, you should always specify degree units. For example, when defining of a rate of temperature change of 2.5 Celsius degrees per day, you should enter "2.5 Cdeg/day", NOT "2.5 C/day".