The present invention relates to a method and system for modifying at least one connection parameter of a circuit switched terminal device, wherein the at least one connection parameter can be modified at a called terminal by a corresponding input operation after the receipt of a setup signaling message. That is, the present invention is a diffusion promoting device connected at just before a separation column and having a function for improving detection sensitivity for use in a low flow velocity high performance liquid chromatographic apparatus. A series of locations are positioned under said top surface and through which used materials are to pass. A plurality of pockets, each constructed from open mesh material, is disposed on the opposed surfaces. The first arm includes a cell and a first switch connected in series, and the second arm includes 121 cells and a second switch connected in series.