I can't speak for the Sapor itself but I've had a number of atomizers like that, where it seemed like it should be adjustable but I couldn't get it to budge. I can only think of one or two situations where the pin really never did loosen up, but at least in my case, the majority of the time the pin seems to be adjustable, it is. Sometimes it just takes some extra patience or careful elbow grease.
But I don't have a Sapor and someone may say it is absolutely not adjustable. Just my 2c.