Mike

You make some very good points with your suggestion and I would not have a problem with the concept you suggest. I agree that the person doing the calculations must use the complete appropriate data if there is any expectation of the results being accurate. Since investigators use 921, I believe that would be a good place to put information about which term is the correct one to use and an explanation as to the reasoning behind the change. If we use the term specific gravity instead of vapor density we reduce some of the variables needed in reaching a conclusion, such as temperature. The term specific gravity then is a better explanation of the thoughts we are attempting to communicate to others as to a particular event. I agree sometimes it is better to have some misused and misunderstood terms disappear.

Unfortunately, there are numerous terms in fire investigation that do not have consistent definition and their use does lead to misunderstandings. Presently, when using a term one needs to identify not only its meaning but must include that person’s definition and cite where the definition is located.

Thanks for bring up these points.

Jim