Siemens Panoramic Dental Tube
Ref. E5
The tube proper is about 8” (20 cm) long and 2.5” (6.2 cm) in diameter. It is an oil immersed, single focus (0.8 mm) tube, fitted with a hooded anode and a beryllium window. A large size external aluminium heat sink is fixed to the anode end of the tube. The strong discoloration of the glass is due to long use, but the filament still tests OK.
The small focus and the relatively large anode fitted with the heat sink are typical of tubes designed to withstand long exposures with a relatively low output and intended to give acceptably sharp pictures with some magnification. These specifications fit perfectly the requirements of panoramic dental X-ray machines generally rated 50-80 Kilovolts, 10-15mA, and exposures of 10-15 seconds.
Note the type number of the tube, starting with the prefix “GE”. I wonder whether this has anything to do with “General Electric” or it is just a fortuitous coincidence