With the introduction of the 835 Vacuum Quality Monitor and 835 Differential Pumping System, Granville-Phillips has added key control features and extended the operating pressure range to enable process monitoring and control. Driving outputs from user-defined equations which utilize the partial pressures from this gas analysis system provides the ability to start and stop a process based on specific conditions. And differential pumping allows operation at both process and base-out pressures. Process pressure operation together with the features required for process control will be covered.