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Medium to Ultra High Vacuum Gauge

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)


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

Part Number




Type BAG302
Messurement range mbar 1.3 x 10-9 … 6.7 x 10-2
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
p < 6.7 x 10-5 mbar electron bombardment, 2 min (default)
p < 5.00 x 10-5 Torr (programmable between 2 … 10 min)
Operation (ambient) °C 0 … +40
Storage °C -40 … +70
Bakeout at flange (sensor only, electrics removed) °C 200
Supply voltage V (dc) +20 … +28
Output signal analog V 0 … +9 (log-linear)
Voltage vs. pressure volts per decade 1
Setpoint relay 1 (single-pole double-throw relay (SPDT))
1 A at 30 V (dc) resistive, or V (ac) non-inductive
Electrical connection D-Sub, 9-pin, male for analog, D-Sub, 9-pin, female for RS485
Interface (digital) RS485
Emission control manual
Filament two Yt2O2 coated Ir
Filament status display / digital output
Digital functions degas, filament on/off and emission control
Materials exposed to vacuum Yt2O3, Ir, W, Ta, stainless steel, glass, Ni
Mounting orientation any
Internal volume cm³ (in.³) 16.4 (1.0)
Weight KF / CF g 270


  1. Datasheet BAG302 EN