The spindle speed is {HEAD ~ a function} of the desired mean thickness of the photoresist, {TAIL ~ the barometric pressure} and the relative humidity 
The spindle speed is { HEAD ~ a function } of the desired mean thickness of the photoresist , { TAIL ~ the barometric pressure } and the relative humidity
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH