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Cold Cathode Ionization Gauges

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Cold Cathode Ionization Gauges



Cold Cathode Ionization Gauges

Cold cathode discharge gauges are an economical and durable alternative to hot filament ionization gauges in the high vacuum pressure regime.  With no active components such as hot filaments, the discharge gauge is not destroyed in sudden or prolonged high pressure gas exposures.


Thermionics offers two types of discharge tubes and a wide variety of connections to new and existing vacuum systems. The choice between the two gauges is based on the anticipated frequency of high pressure exposures and the nature of the residual gases in the vacuum. While these exposures will not often ruin the gauge, some deposition of foreign material may occur on the internal electrodes. To prevent a cumulative degradation in tube performance, the electrodes may be removed and cleaned. This significantly prolongs the lifetime of the gauge operation, but is usually not a problem under typical vacuum environments. Thermionics offers a standard unit (DG-7) for typical operation and an additional unit with an easily removable anode assembly (DG-8) for the more austere applications.


  • 2 gauge models and compatible control model
  • Self cleaning, minimum maintenance
  • Rugged, all welded construction
  • With or without O-rings or gaskets on standard models
  • Viton® O-ring on removable anode model
  • Long, uninterrupted service life
  • Small size
  • Connectable to glass or metal systems

Ordering Information

Model No. Description
DG-7 Standard tube with stainless steel (SS304) envelope, all welded construction and terminated with 3/4″ tubulation. Bakeable to 250°C.
DG-8 Same anode configuration as DG-7 except O-ring assembly ring allows for removal of the anode for inspection and cleaning. Bakeable to 150°C (Viton® limit).

Additional Terminations

Suffix Description
-1/2SS 1/2″ stainless steel tubulation
-CF 3/4″ tubulation with 2-3/4″ ConFlat flange connection
-QD 1/2″ tubulation to quick-disconnect fitting
-KF 3/4″ tubulation to KF-40 fitting
-1/2G 1/2″ glass tubulation

Call or email with your requirements and for current pricing.

800.962.2310 /