The 2456 replaces the obsolete model 2455. It is intended for use with a 2465 piston gauge to monitor the system level sensors and input from the LEM (Laboratory Environmental Monitor). It can be interfaced with a computer and is compatible with either WinPrompt or COMPASS for Pressure software.
Application hint: The 2456-801 is a dual channel version. If only one channel will be used it must be Channel "A". In the attached photo the LEM is connected to the serial port for the Air Density Module and the host computer connection is at the bottom of the rear panel.