Abstract: A heater equipped pre-trap chamber is provided at the upstream side of the inlet to a vacuum diaphragm pump so that gas products and solvent drawn from a specimen in a drying chamber can be subjected to a separation operation in the pre-trap chamber to remove liquid and readily condensable vapor forms of solvent. This thereby prevents entry of liquid solvent to the pump unit where it could cause damage. The inlet to the pump is located some distance above the outlet from the pre-trap chamber so that any liquid as may carryover in the flow from the pre-trap chambers towards the pump inlet, will return to the pre-trap as a gravity induced back flow. Solvent collected in the pre-trap chamber is heated to vaporize it and pass it out through the pump in that form to the outside atmosphere, making the pre-trap self-cleaning.

Abstract: A heater equipped pre-trap chamber is provided at the upstream side of the inlet to a vacuum diaphragm pump so that gas products and solvent drawn from a specimen in a drying chamber can be subjected to a separation operation in the pre-trap chamber to remove liquid and readily condensable vapor forms of solvent. This thereby prevents entry of liquid solvent to the pump unit where it could cause damage. The inlet to the pump is located some distance above the outlet from the pre-trap chamber so that any liquid as may carryover in the flow from the pre-trap chambers towards the pump inlet, will return to the pre-trap as a gravity induced back flow. Solvent collected in the pre-trap chamber is heated to vaporize it and pass it out through the pump in that form to the outside atmosphere, making the pre-trap self-cleaning.

Abstract: Master units and slave units are preferably housed in identical housings. Each master unit comprises a Central Intelligence Unit (CIU) which in turn comprises a drum processor and a communications processor, and an Input/Output Unit (IOU) having input terminals and relays for connection to external devices. Each slave unit comprises an IOU. Each IOU is connected to its CIU through a Local bus (L-bus). Up to sixteen IOU's may be controlled by a single CIU.Up to 16 master units may be connected together by means of console bus (C-bus) and a data exchange bus (X-bus), in which case each master unit is given control of specified "X" variables for update. Each "X" variable has a specific time slot on the X-bus and all "X" variables are stored on an X-drum at each master unit.The C-bus may be connected to a computer terminal at each master for programming of all CIU's, or to computer devices, or to long distance communication lines.