Abstract: The present invention is a liquid chromatograph comprising a chromatographic column; means, including a pump, connected to the input of the column for injecting a sample under pressure into the column; and a detector system, including an optically transparent flow cell and a connecting means connecting the flow cell to the output of the column. The connecting means is in thermal contact or at least thermal equilibrium with the flow cell for a sufficient length so that any liquid passing through the connecting means comes to thermal equilibrium with the flow cell before entering the optically transparent flow cell.