As indicated above the prior art sought to control {TAIL ~ the charge} per {HEAD ~ unit mass} of the toner and thus the calibration of the printer using low field conductivity measurements of the toner 
As indicated above the prior art sought to control { TAIL ~ the charge } per { HEAD ~ unit mass } of the toner and thus the calibration of the printer using low field conductivity measurements of the toner
OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH