Paper VT-MoM8
On the Stability of Capacitance-Diaphragm Gauges with Ceramic Membranes
Monday, October 31, 2011, 10:40 am, Room 111
Capacitance-diaphragm gauges with ceramic membranes or diaphragms have been on the market for
about 15 years. The long-term stability of these devices with full scales from 13 Pa to 133 kPa
has been tested in the past decade by the calibration of gauges used by the manufacturer as reference
gauges on the production line. These reference gauges were calibrated annually on a primary
standard. It was found that the reproducibility of these devices depends on their full scale. For
13 Pa, the annual reproducibility near full scale varied between 0.02% and 0.05%, and for full scales
of 133 Pa and higher, it varied between 0.005% and 0.03% of full scale. The reproducibility of the
ceramic capacitance-diaphragm gauges for full scales of 133 Pa and 1.3 kPa was significantly lower
than the uncertainty of a primary standard applying the static-expansion method.