In this case the flowmeter 6 will register a flow which is nil or close to zero, such a measurement indicating {TAIL ~ the presence} of the casing over an area with {HEAD ~ a bonding defect} 
In this case the flowmeter 6 will register a flow which is nil or close to zero , such a measurement indicating { TAIL ~ the presence } of the casing over an area with { HEAD ~ a bonding defect }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD