. The American journal of roentgenology, radium therapy and nuclear medicine . TUBES. A. Universal Type. When the exhaustof the tube is completed, it is sealed off fromthe exhaust system. After an interval of atleast twenty-four hours, it is given a prelim-inary test. This consists of running at a sixinch parallel spark gap with sufficient cur-rent through the tube to heat the anode to awhite heat, and then increasing the gap toten inches. Tubes which show appreciablegreen fluorescence in the bulb are rejectedand must be re-exhausted. Tubes w^hich passthe first test are provided with anode and
. The American journal of roentgenology, radium therapy and nuclear medicine . TUBES. A. Universal Type. When the exhaustof the tube is completed, it is sealed off fromthe exhaust system. After an interval of atleast twenty-four hours, it is given a prelim-inary test. This consists of running at a sixinch parallel spark gap with sufficient cur-rent through the tube to heat the anode to awhite heat, and then increasing the gap toten inches. Tubes which show appreciablegreen fluorescence in the bulb are rejectedand must be re-exhausted. Tubes w^hich passthe first test are provided with anode andcathode bases, and after a certain time-inter-\al given a second test which is a duplicateof the first. A third test is made just beforeshi[)ment. B. Radiator Type, (a) 10 MilliampereTube.—The test of the radiator type tubediffers considerably from that of the Univer-Scd type. The preliminary test of the 10milliampere tube consists in running for twominutes with 5 milliamperes at 40 KV., oneminute with 5 milliamperes at 50 KV., andone minute with 10 milliamperes at 60 FiG. 8. Oven and Exhaust System for ExhaustingA-Ray Tubes. After basing and after a certain time-inter-val, the tube is given the second test, whichconsists of running continuously for twominutes at 10 milliamperes and 60 KV. 26o Manufacture of the Coolidge .Y-Ray Tube Tubes are rejected which show appreciablegreen fluorescence in the bulb. During the two minute run, three pinholecamera focal-spot pictures of the tube aremade on a dental film. Two of these aremade with differently timed short exposuresand show the distribution of the energy over twenty-five second run with 30 milliamperesand 60 KV. Focal spot pictures are takenduring this run. (c) Dental Tube.—The first test is sim-ilar to that of the 10 milliampere tube exceptthat the highest voltage used is 50 KV. Thesecond test consists of a two minute run with
Size: 1969px × 1269px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, bookidamericanjour, bookyear1906
