When placing one if the dynamic sector light objects in a map, one of the parameters is "intensity scale". What does that actually do?

I mean, I know that the bigger the value, the wider the diameter of the light - but I can't figure out what the multiplication factor is.

For example, if I place a sector light in a sector that has light value 128, the dynamic light does not seem to have a radius of 128, if I give it an intensity scale of 1, or 256 if I give it a scale of 2, and so on; which is just as well, because those would generally be too big anyway. So I assume that the multiplication factor is less than 1. Even at that, the factor is a bit crude. I have often wanted to make something where factor 1 was a bit too small but 2 was a bit too big but the parameter can only be an int.

So, anyway, what is the maths behind the intensity scale parameter?