Sensors & Feedthroughs

Front Load Single Sensor


Product configurator

Gemini™ MxG5xx

Sensor version
Ionization chamber
Emmision current
Flange connection to vacuum chamber
Switching function
Electrical connection
Digital interface
Analog output signal
Your configuration
Gemini™ MxG5xx
Switching functions
Electrical Connection
FCC, 8-pin
Digital Interface
Measurement range
1.2 - 8.68 V
Personal information
Gemini™ MxG5xx
Gemini™ MAG500
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INFICON Front Load Single crystal sensors offer proven reliability and durability and have the best thermal stability of any sensor head on the market. 

The front load design allows for easy insertion of the crystal holder in applications lacking sufficient room for side insertion.  Assembled mechanically rather than soldered, parts can be replaced conveniently in the field, if necessary. Sensors can be ordered individually or in a sensor / feedthrough combination that can be either welded or assembled with compression fittings.


  • Front load crystal holder
  • Easy installation
  • Available with 2.54 cm (1 inch) bolt feedthrough / CF40 Feedthrough
  • Adjustable length if ordererd with compression fittings
  • Sensor / Feedthrough combinations available welded to customer specified lengths
  • No brazing required if ordered with compression fittings or welded to feedthrough


Maximum operating isothermal environment temperature with minimum water flow400° C
Water tube1/8 in. (3.175 mm) O.D. seamless stainless steel
Crystal exchangeFront loading; self-contained package for ease of exchange
Feedthrough Specifications 1 in. bolt and Ultra-Torr (compression fitting) terminations:
Materials304 stainless steel, Teflon®, ceramic, beryllium nickel, VITON®
TemperatureOperational environment to 300° C with water cooling or 165° C without
Mounting1.015 in. ±0.010 in. diameter aperture
Download full specifications


QCM Sensor FeedthroughsQCM Sensor Feedthroughs
Quartz Monitor CrystalsQuartz Monitor Crystals

Spare Parts

Part NumberDescription
007-007Retainer spring (for crystal holder)
007-023Ceramic Retainer
080-018Set screw (for female coax)
750-903-G1Standard Sensor Kit - Includes standard set screw, ceramic insulator, Teflon screw
750-904-G1Compact Sensor Kit - Includes compact set screw, ceramic insulator, Teflon screw
750-115-P4Coupling (installs onto bellows assembly)
750-169-P2Bellows assembly (coupling not included)
750-171-P1Finger spring contact
750-172-G1Crystal holder (includes retainer spring)
750-174-P2Female coax
750-188-P3Leaf Spring
750-210-G1Shutter module (bellows assembly, shaft assembly, and shutter assembly)
750-215-G1Shaft assembly (part of shutter module)
750-216-G1Shutter assembly (part of shutter module)
In-vacuum cables 
321-039-G12In-vacuum cable, 15.2 cm (6 in.)
783-500-023In-vacuum cable, 25.4 cm (10 in.)
007-252In-vacuum cable, 30.5 cm (12 in.)
321-039-G11In-vacuum cable, 61.0 cm (24 in.)
783-500-024In-vacuum cable, 76.2 cm (30 in.)
007-044In-vacuum cable, 78.1 cm (30.75 in.)
007-059In-vacuum cable, 91.4 cm (36 in.)
007-061In-vacuum cable, 121.9 cm (48 in.) - Requires ModeLock controller
321-039-G13In-Vacuum Cable, 154.2 cm (60 in.) - Requires ModeLock controller
321-039-G14In-vacuum cable, 182.9 cm (72 in.) - Requires ModeLock controller
321-039-G15In-vacuum cable, 3.5 m (137.8 in.) - Requires ModeLock controller and 4 m XIU
321-039-G16In-vacuum cable, 4 m (157.5 in.) - Requires ModeLock controller and 4 m XIU
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