A fast, accurate, low offset comparator may be configured with multiple gain stages. The invention matches workers to shifts in a manner that minimizes fatigue while on shift and maximizes shift worker effectiveness. The dip tube member may be adapted to extend outward of the distal end of the man housing element. In certain embodiments, the control uses external master magnets that rotate around an axis orthogonal to the longitudinal axis of the housing to drive internal slave magnets magnetically. The air is transmitted from the first vane set to the first and second balance weight portions, and then is discharged via the second vane set through the air outlets at another side of the machine tool to form cross cooling airflow.