We are in the process of installing an on-line DOC analyzer to our Agilent 1100 HPLC. We are running ChemStation (version B/04.01 SP1 (650)). We need to purchase a Universal Interface Box (UIB), and the vendor is suggesting we obtain one from Agilent. It appears, however, that the necessary model (G1390A) is no longer sold by Agilent. My question is what specifications do I need in a UIB to ensure the unit will work? I believe I know what a UIB does but not necessarily how (specifically) it works and do not want to purchase the incorrect unit.