Patent ID: 8293035

Claim:
A process for treating a workpiece, said process comprising the steps of: (a) altering a temperature of a workpiece surface wherein at least one condition is selected from the group consisting of: thermal treatment rate, relative motion between the surface and a thermal treatment means, coolant flow rate onto said surface, heating flow rate onto said surface and the relative speed between a thermal treatment means and the surface is controllable; (b) simultaneously measuring temperatures at a plurality of locations over the surface of the workpiece; (c) determining an average temperature of the temperatures measured in step (b); (d) comparing the average temperature to a preselected minimum temperature and a preselected maximum temperature for the workpiece; (e) automatically adjusting at least one of the conditions from step (a) if said average temperature is not between the preselected minimum temperature and the preselected maximum temperature for the workpiece; (f) determining the standard deviation between said average temperature and a cumulation of said measured temperatures; (g) comparing the standard deviation to a preselected standard deviation, S2; and (h) suspending or limiting said altering step if said standard deviation is greater than said preselected standard deviation, S2.