Hot Ionization Gauges


Medium to Ultra High Vacuum Gauge

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Gemini™ MxG5xx

Sensor version
Ionization chamber
Emmision current
Flange connection to vacuum chamber
Switching function
Electrical connection
Digital interface
Analog output signal
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Gemini™ MxG5xx
Switching functions
Electrical Connection
FCC, 8-pin
Digital Interface
Measurement range
1.2 - 8.68 V
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The INFICON single Bayard-Alpert Hot Ion gauge BAG302 covers a wide measurement range from 1.3 × 10-9 to 6.7×10-2 mbar (1 × 10-9 to 5 × 10-2 Torr). 

The compact All-In-One Hot Ion gauge BAG302 offers an easy to exchange dual filament sensor, a built in OLED display, set-point relay and a log-linear analog output as well as an integrated RS485 digital interface for increased integration flexibility. These features combined with the rugged design makes the BAG302 an affordable and repeatable process to base pressure measurement instrument of its own and provides a high value/ low cost of ownership choice.


  • Wide measurement range from 1.3 × 10-9 to 6.7×10-2 mbar(1 × 10-9 to 5 × 10-2 Torr)
  • Two standard long-life yttrium oxide coated iridium filaments
  • All-in-One active gauge with built-in display, set-point, analog output and standard integrated RS485 digital interface
  • Bright digital OLED display with keypad for simple setup, operation and programming
  • User programmable set point relay
  • User programmable display units in mbar, Torr or Pa
  • User selectable Auto-ranging of emission current
  • Mechanical strength and ruggedness
  • Choice of various flange options
  • Easy to exchange sensing element
  • Compliance & standards: CE, RoHS
  • Direct drop in replaces Granville-Phillips® 354 Micro-Ion® Module – identical control functions including softwarecommands (RS485) (Granville-Phillips® and Micro-Ion® are registered trademarks of MKS Instruments, Andover, MA)

Typical applications

  • Pressure measurement in semiconductor process and transfer chambers
  • Industrial coating
  • General vacuum measurement and control in the low to ultra high vacuum range


Measurement range (air, O2, CO, N2)mbar
1.3 x 10-9 ... 6.7 x 10-2
1 x 10-9 ... 5 x 10-2
1.3 x 10-7 ... 6.7
Accuracy (N2)  
1.3×10-8 … 6.7 ×10-2 mbar% of reading±15
1×10-8 … 5×10-2 Torr% of reading±15
Repeatability% of reading±5
Temperature°C+10 … +50
Operation (ambient)°C0 ... +40
Storage°C-40 ... +70
Bakeout at flange (sensor only, electrics removed)°C200
Supply voltageV (dc)+20 ... +28
Setpoint relay 1 (single-pole double-throw relay (SPDT))
1 A at 30 V (dc) resistive, or V (ac) non-inductive
Materials exposed to vacuum Yt2O3, Ir, W, Ta, stainless steel, glass, Ni
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BAG302 Ordering information
BAG302 Ordering information
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