Wear Of Grinding Stone

[Hamlet]

Hoi!

I don't know why I am asking this here, but feels like the right place. For example the TwinPeaks intro:
http://www.youtube.com/watch?v=7oDuGN6K3VQ Starting at 00:14
How do these grinding machines, I mean in general, in the industry, compensate for wear?
That one in the video looks pretty stationary, without feedback.

Hamlet

EDIT
Why the hell did I post this under Analog electronics!? Could someone move it somewhere appropriate, like general? Thanks.

[CWB]

ahhh ... the filing room .
the machines i seen used pressure (think settable spring loaded) .

[Hamlet]

That is what I thought of. The loss of weight probably does not matter that much.

[CWB]

the stones used are fairly hard . the amount of material removed is small .
a saw band/blade is only used for a short time before it is pulled and filed .
a dull or damaged band/blade will not cut smoothly , runs hot and will "walk" when making a cut .
some blades have carbide steel inserts/teeth that are brazed onto each tooth ... these are replaced if they become damaged (think hitting a rock or nail) or have excessive wear .

[tekwiz]

Industrial grinding machines, such as surface grinders, cylindrical grinders, & the ones in the vid, all have diamond dressers to put a fresh, accurate surface onto the wheel whenever necessary. Grinding techniques meant to spread wear evenly over the wheel surface are also used so a wheel doesn't have to be dressed as often. The saw sharpening wheels in the vid are redressed before wear becomes enough to cause problems. They can sharpen an entire blade without needing compensation. The depth of cut is then adjusted for the next blade, based on how much metal has been removed by previous sharpenings & how dull the teeth are.
A properly dressed surface of even a coarse grinding wheel will feel absolutely smooth if lightly touched while turning. I don't recommend this method of checking, however.
Diamond dressing tools are available for any grinding wheel.