Hitachi ChromasterUltra Rs 6270 Instruction Manual page 60

2.2 Operating Principle and Functional Description
Figure 2-17 Releasing the Pressure (INJECT → LOAD Switching)
(f) Pressure release (LOAD switching)
Switch the injection valve to the LOAD side to release
pressure in the loop.
vd: Dead volume (the instrument inside parameter)
vi: Injection volume (the sample net volume to the flow path)
vl: Lead volume (forward part, cut volume)
vr: Rear volume (rearward part, cut volume)
va: Air volume (the air volume which sample is sandwiched.)
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