8tinb25e1 (2016-04)
1 Introduction / General Information
1.1 Description
The VGC031 vacuum gauge controller is a convenient and inex-
pensive power supply and readout instrument for the INFICON
PGE050 Pirani Gauge Enhanced or a Granville-Phillips® 275
Convectron®. The 1/8-DIN housing can be used as a bench top,
or mounted in a cutout in an instrument panel. The VGC031 is
powered by user supplied 12 to 28 V (dc), 2 W, or by the
INFICON power supply.
Thermal conductivity gauges measure pressure indirectly by
sensing the loss of heat from a sensor to the surrounding gases.
The higher the pressure of the surrounding gas, the more heat is
conducted away from the sensor. Pirani thermal conductivity
gauges maintain a sensor (usually a wire) at some constant tem-
perature, and measure the current or power required to maintain
that temperature. A standard Pirani gauge has a useful measur-
ing range of about 10-4 Torr to 10 Torr. By taking advantage of
convection currents that are generated above 1 Torr, convection-
enhanced Pirani gauges increase the measuring range to just
above atmosphere.
The VGC031 signals and relay functions are the same as found
on similar convection gauge controllers from other manufactur-
ers. The VGC031 Controller, PGE050 vacuum gauge tube and
gauge cable can be directly interchanged with MKS Instruments
/ Granville-Phillips® (GP) 375 or 475 controller, 275 Convec-
tron® gauge and gauge cable (Remote interface, relay and pow-
er connectors are different). Various analog output scaling pro-
vide signal compatibility with GP controller series 375, 475, the
original GP 1/4 DIN 275 Analog Convectron Gauge Controller as
well as the Mini-Convectron® module.
