Liquid Chromatography Detectors - Dispersion in Detector Sensors > Dispersion in the Detector Sensor Volume > Dispersion in Detector Sensors Resulting from Newtonian Flow > Page 12

 

 

Figure 6 The Design of a Modern Absorption Cell

 

The Newtonian flow is distorted by the manner in which the inlet and outlet conduits are connected to and from the cell. Mobile phase enters the cell at an angle that is directed at the cell window. It follows, that the mobile phase flow has to virtually reverse its direction to pass through the cell producing a swirling action which introduces strong radial flow and disrupts the Newtonian flow. The effect also occurs at the exit end of the cell. The flow along the axis of the cell now must reverse its direction to pass out of the port which is accomplished by attaching the exit conduit at an angle to the axis of the cell. Employing this type of entry and exit connections eliminates dispersion resulting from viscous flow.