Power number, mixing limiting values

Conventional TNT-equivalency methods state a proportional relationship between the total quantity of flammable material released or present in the cloud (whether or not mixed within flammability limits) and an equivalent weight of TNT expressing the cloud s explosive power. The value of the proportionality factor—called TNT equivalency, yield factor, or efficiency factor—is directly deduced from damage patterns observed in a large number of major vapor cloud explosion incidents. Over the years, many authorities and companies have developed their own practices for estimating the quantity of flammable material in a cloud, as well as for prescribing values for equivalency, or yield factor. Hence, a survey of the literature reveals a variety of methods. 

The operations are straightforward and can be performed on cells, numbers and functions. The operations +, —, and / indicate addition, subtraction, multiplication and division as in most environments powers are indicated by ". Brackets can be used and there is no practicable limit to the size of the expression or the amount of nesting. A destination cell must be chosen. Hence the operation =3 (2—5)"2/(8—1)+6 gives a value of 9.857. All the usual rules of precedence are obeyed. Operations can mix cells, functions and numbers, for example =4 A1+SUM(E1 F3)—SUMSQ(Y) involves adding... 

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