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

Paper VT-TuM3
Extension of the Spinning Rotor Gauge to Lower Pressure

Tuesday, October 26, 1999, 9:00 am, Room 610

Session: Total and Partial Pressure Gauging
Presenter: J.P. Looney, National Institute of Standards and Technology
Correspondent: Click to Email

The Spinning Rotor Gauge (SRG) is widely used for vacuum gauge calibration and measurement in the pressure range 0.1 Pa to somehwat below 10 @super -4@ Pa (10 @super -6@ Torr). The lower limit of presently available SRGs is due to essentially two factors (i) the ability to measure the rotor deceleration rate with a precision of better than about 10 @super -10@ s @super -1@ and (ii) large residual torques on the rotor. The first can be overcome by improved timing of the rotation rate of the ball and the second can be overcome by development of suspension heads with smaller residual torques on the spinning rotor. Together, a system can be constructed to make measurements to much lower pressures, perhaps below 10 @super -6@ Pa (10 @super -8@ Torr) with an imprecision of <1% for a four minute measurement interval. The factors which limit the useful pressure measurement range of the SRG will be dicsussed and initial performance measurements for a prototype system will be presented.