In this manner, the atmosphere, acting as {HEAD ~ a control pressure}, is introduced into {TAIL ~ a variable pressure chamber} defined within the housing 
In this manner , the atmosphere , acting as { HEAD ~ a control pressure } , is introduced into { TAIL ~ a variable pressure chamber } defined within the housing
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH