I have read the discussion regarding UPLC accelerates regular HPLC column degradation. Very helpful information!But I have another question: what is the pressure a column experiences in the UPLC system? I test my UPLC by connecting the inlet and outlet in the sample manager with a union, and run water @ 1 ml/min. The pressure reading is 1000 psi. That's the pressure comes from the resistance of the narrow tubing and the pressure regulator at the detector. Now I install a column, and get a pressure reading of 5000 psi. So the column is experiencing 4000 psi "real" pressure. Am I right? According to the column manual, my column maximum pressure should be under 4500 psi. If my assumption was correct, I can still run this column in the UPLC as the 5000 psi pressure reading is not the real pressure drop across the column.