AVS 46th International Symposium
    Vacuum Technology Division Tuesday Sessions
       Session VT-TuM

Paper VT-TuM8
New Enhanced Performance Low Pressure Capacitance Manometer

Tuesday, October 26, 1999, 10:40 am, Room 610

Session: Total and Partial Pressure Gauging
Presenter: C.P. Grudzien, MKS Instruments
Correspondent: Click to Email

The measurement performance of low pressure capacitance manometers has traditionally been influenced to varying degrees by many factors including barometric pressure, ambient temperature change, shock, vibration, material creep and rapid pressure excursions. Many improvements and developments have occurred since the original capacitance manometer technology was invented over forty years ago. Previous capacitance manometer designs address several of these pressure independent influences, but in the process, trade off performance in other areas. A new enhanced performance design is described here that incorporates several unique approaches to reducing these influences and provides for a practical, robust platform. The unique radial 'spoke' geometry isolates the sensitive capacitance elements from unwanted body forces and thermal transients, yielding stable zero and span performance. Experimental data and computer simulation show that measurements using instruments with full scale ranges of 100 mTorr (~10 Pa) and below are superior to that of previous state-of-the-art methods. The enhanced performance capacitance manometer design establishes a basis for continual improvement and a path to meet the future requirements of the vacuum community.