{TAIL ~ a pair} of {HEAD ~ orifice plates}, each said plate being disposed in a respective flow system between said clamping device and said reservoir to create a measurable pressure drop in a fluid passing therethrough 
{ TAIL ~ a pair } of { HEAD ~ orifice plates } , each said plate being disposed in a respective flow system between said clamping device and said reservoir to create a measurable pressure drop in a fluid passing therethrough
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 OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH