The second plate has {HEAD ~ an outwardly extending indicating plate} with a pair of spaced pins, and an indicating strip for measuring the height of {TAIL ~ liquid} collected in the compartment 
The second plate has { HEAD ~ an outwardly extending indicating plate } with a pair of spaced pins , and an indicating strip for measuring the height of { TAIL ~ liquid } collected in the compartment
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH