Temperature sensors, such as pyrometers, that do not contact the wafers being preheated, measure temperature for {HEAD ~ control} of {TAIL ~ the heating} of the lamps 
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Temperature sensors , such as pyrometers , that do not contact the wafers being preheated , measure temperature for { HEAD ~ control } of { TAIL ~ the heating } of the lamps
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH