Acoustic emission is the elastic-wave signature of the grinding zone: grain contact, chip formation, friction and wheel wear all radiate into the kilohertz-to-megahertz band. It is the most direct process signal in grinding — and the most demanding to acquire, because everything interesting happens above the rate a general-purpose data acquisition card runs at.
The setup
The lab's tool grinding centre carries an acoustic-emission sensor on the workpiece side, a current clamp on the spindle feed and a trigger line from the machine that goes active for every pass. The AE sensor feeds a dedicated high-speed digitiser on its own EdgeBox; current and trigger go into the standard DAQ on the machine's acquisition box. All three land in the same archive on the same timebase.
Why the acquisition path matters
A general-purpose acquisition card sees that the wheel is in contact. The structure inside the emission — the part that carries information about the process — needs a dedicated high-speed front end and a pipeline that can carry its data into the archive without loss. Getting the analogue side right matters as much as the digitiser: a badly matched input can turn a rich signal into a flat line.
Because acoustic emission and spindle current share one timebase, every emission feature can be computed exactly inside the window in which the wheel is actually cutting, and compared across passes, parts and days.
Why the rate is not a marketing number
A digitiser's headline rate and the rate at which a pipeline can sustain capture into a permanent archive are different numbers, and only the second one matters to a customer. When we quote a rate, it is the second one.
