The
BA-2 BA Glass Thoria-Coated Iridium Filament TubeThe
BA-2 BA Glass Thoria-Coated Iridium Filament TubeThis BA glass tube uses a single filament of thoria-coated iridium. This filament type can produce the required emission current at relatively low temperature because of the low work function of thoria. Further, the low reactivity of iridium makes the tube's filament unlikely to burn out. NIST tests on tubes with thoria-coated iridium filaments show a higher tube-to-tube variation in gauge factor than the tungsten filament tubes. The nominal gauge factor for this tube is 9/Torr.
Note that this type of filament bends very easily; if the tube is air released suddenly, the inrush of air may permanently bow the filament, causing a substantial and unpredictable change in the tube’s gauge factor.
In the drawing the pins for the filament are labeled F and the ends of the grid are attached to the pins labeled G. The ion collector wire passes through the top of the tube. To connect this tube to the IGC-10 Ion Gauge Control use cable CBL-2.
BA-2/.75 Thoria-Coated Iridium Filament Glass Tube, uncalibrated, with 0.75" D glass tubulation: $90.00
BA-2/1 Thoria-Coated Iridium Filament Glass Tube, uncalibrated, with 1" D glass tubulation: $100.00
BA-2/.75/K Thoria-Coated Iridium Filament Glass Tube, uncalibrated, with 0.75" D Kovar sleeve tubulation: $100.00
BA-2/1/K Thoria-Coated Iridium Filament Glass Tube, uncalibrated, with 1" D Kovar sleeve tubulation: $100.00
BA-2/C Thoria-Coated Iridium Filament Glass Tube, uncalibrated, with 2-3/4" Conflat® flange: $170.00
BA-2/KF25 Thoria-Coated Iridium Filament Glass Tube, uncalibrated, with NW 25 fitting: $170.00
BA-2/.KF40 Thoria-Coated Iridium Filament Glass Tube, uncalibrated, with NW 40 fitting: $170.00
BA-2/.75/CERT Thoria-Coated Iridium Filament Glass Tube, calibrated traceable to NIST, with 0.75" D glass tubulation: $230.00
BA-2/1/CERT Thoria-Coated Iridium Filament Glass Tube, calibrated traceable to NIST, with 1" D glass tubulation: $240.00
BA-2/.75/K/CERT Thoria-Coated Iridium Filament Glass Tube, calibrated traceable to NIST, with 0.75" D Kovar sleeve tubulation: $250.00
BA-2/1/K/CERT Thoria-Coated Iridium Filament Glass Tube, calibrated traceable to NIST, with 1" D Kovar sleeve tubulation: $25.00
BA-2/C/CERT Thoria-Coated Iridium Filament Glass Tube, calibrated traceable to NIST, with 2-3/4" Conflat® flange: $320.00
BA-2/KF25/CERT Thoria-Coated Iridium Filament Glass Tube, calibrated traceable to NIST, with NW 25 fitting: $320.00
BA-2/.KF40/CERT Thoria-Coated Iridium Filament Glass Tube, calibrated traceable to NIST, with NW 40 fitting: $320.00