Our online catalog is being updated! Please contact us for current pricing. Nude Ionization Gauge and Flange Assemblies Nude Ionization Gauge and Flange Assemblies Nude bakeable gauge tube Nude gauges are used when direct access to a vacuum chamber is needed. Nude gauges prevent errors which have been ascribed to glass envelopes and associated tubulations. They have a closed grid structure which minimizes gas reactions and improves sensitivity by a factor of 2-1/2. The improved sensitivity and a .005" collector results in a low x-ray limiting current corresponding to a pressure of about 2 x 10-11 Torr. The gauge is available mounted on a 2-3/4" O.D. UHV flange, greatly simplifying filament replacement. Standard filaments are made of tungsten. For long life in higher pressure and/or active gas environments, we recommend use of the thoria-coated iridium filament. Medium to UHV Vacuum Pressure Measurement Range: 10-3 to 10-11 Torr Linear response in 10-4 and 10-5 Torr ranges with reduced emission Nude configuration Bayard-Alpert type Specifications Nude Bakeable Bayard-Alpert Gauge Tube Specifications Vacuum range 1 x 10-3 to 2 x 10-11 Torr Filament voltage 3-4.5V Filament bias 30 VDC Filament current 2.5-3.5 A with emission current of 4 mA Grid voltage 180 VDC Collector Voltage 0 VDC Sensitivity 0.1 A/Torr @ 4 mA grid current (N2 equivalent) Degas method Electron bombardment (30 - 40W @ approx. 500 V) Flange 2.75" (70 mm) O.D. ConFlat flange Length 4.12" overall, 3" insertion length Filament Two tungsten filaments, two thoria-coated iridium filaments or two tungsten rhenium filaments on replaceable filament assembly Grid Tantalum grid on platinum-clad molybdenum supports with top and bottom caps Ordering Information Ion Gauge Tubes. -x refers to option suffixes below Model No. Description Price IG-2-x Nude ionization gauge tube mounted on 2-3/4" ConFlat flange. $375. IG-2F-x Replacement filaments for nude ion gauge tube. $99. Options Suffix Description Additional Price -W Tungsten filaments N/C -I Thoria-coated iridium filaments $10. To order: For example, to order a Pyrex encapsulated tube with thoria-iridium filaments and terminated with a ConFlat flange, one would write: IG-1-P-I-CF.