What does the Relative Effectiveness Factor (REF) measure?

The Relative Effectiveness Factor (REF) is a measurement that evaluates an explosive's performance in relation to a standard reference, typically TNT (trinitrotoluene). This factor provides a comparative measure of an explosive's detonation power, which is crucial in determining how effective the explosive will be in different applications, particularly in military or engineering contexts. By using TNT as a baseline, the REF allows for a straightforward understanding of how various explosives compare in terms of their energy release and effectiveness in producing explosive effects.

The other choices pertain to different concepts. The environmental impact of explosives relates to factors such as chemical composition and byproducts, which is not what the REF quantifies. The speed of detonation is a distinct characteristic of explosives, often discussed in terms of velocity of detonation, but this does not define the REF. Lastly, the physical size of an explosive charge pertains to the volume or weight of the material itself, not its effectiveness or power compared to a standard like TNT. Therefore, the REF specifically measures detonation power in relation to TNT, making this the correct interpretation.