PISTON POSITION DETECTION FOR PREPARATIVE CHROMATOGRAPHY COLUMN

摘要

In an axial-flow cylindrical preparative chromatography column that utilizes a piston to close off the top of the resin space inside the column and thereby eliminate void spaces at the top of the resin, one or more proximity detectors are incorporated in the piston head to either generate a signal indicating the proximity of the piston had to the resin, or to collect a signal, such as a optical signal, emitted from the resin. The value of the signal or any change in the signal is compared to a threshold value to ascertain when the piston head is in proximity to the resin so that the motion of the piston toward the resin can be halted before contact pressure from the piston head damages the resin.