The MS utilizes one external forepump and one internal turbomolecular pump. The external forepump creates the vacuum necessary to operate the turbomolecular pump. It also evacuates the ion transfer tube region of the vacuum manifold. The forepump must be plugged into a single-phase 230 Vac wall outlet; this outlet cannot also have the MS plugged in. A relay control cable connection between the forepump and the V65 Pump Enable connector in the power entry module lets the MS turn on and off the forepump remotely. The Main Power switch located in the power entry module controls the V65 Pump Enable connector, not the Electronics switch. For a diagram, see Power Entry Module.
The turbomolecular pump controls the vacuum for the vacuum regions. It also sends status information, such as temperature or rotational speed, to the data system computer. The Main Power switch turns off the turbomolecular pump. The Electronics switch has no effect on this pump. Power to the turbomolecular pump is automatically turned off if the pump temperature becomes too high.
NOTE
An Edwards nXR120i dry vacuum forepump is the standard option that is included with the MS.