As will be discussed below, this ringed shaped portion establishes a reference region 86 used in distinguishing between {HEAD ~ mobile ion drift} and other effects of temperature stress on {TAIL ~ contact potential measurements} 
As will be discussed below , this ringed shaped portion establishes a reference region 86 used in distinguishing between { HEAD ~ mobile ion drift } and other effects of temperature stress on { TAIL ~ contact potential measurements }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL