I've heard some people give accurate measurements on their grind angle. I wonder what they use to measure it.
THere are lots of methods. Here is one: http://www.chadwrites.com/knife-sharpen ... le-finder/
Personally I use an adjustable base to hold my sharpening stones so that the knife is held flat (like a spoon) for grinding/beveling/sharpening. I use my iPhone to guage the angle I want, then make it happen! I discuss it briefly in one of my videos if you want to see a demo.
(Start watching at about 25 seconds)
I have also seen laser measuring devices that tool manufacturers use...I would imagine these would be cost prohibitive to most smaller businesses and certainly would not make much sense for an enthusiast to own one...unless he/she is REALLY into knives. (Spyderco probably has a few of these).
I view these tools as optional equipment for even the advanced sharpening gurus. They typically can look at an edge and guess pretty close...and the absolute angle is somewhat trivial, it is more a matter of how the knife performs relative to whatever angle it has, then adjusting accordingly. That said, if you are really fine tuning things, such a tool becomes handy, but needs to measure finer than 5 degree jumps IMO.