target evaluating means for viewing said luminescent target means and for processing {TAIL ~ luminescent values} at selected test points to develop {HEAD ~ test values} as a function of luminescent values; and 
target evaluating means for viewing said luminescent target means and for processing { TAIL ~ luminescent values } at selected test points to develop { HEAD ~ test values } as a function of luminescent values ; and
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH