File:Radiography, x-ray therapeutics and radium therapy (1915) (14755347044).jpg

Identifier: radiographyxrayt00knoxuoft (find matches)
Title: Radiography, x-ray therapeutics and radium therapy
Year: 1915 (1910s)
Authors: Knox, Robert, 1868-1928
Subjects: Radiography Radiotherapy X-rays
Publisher: London : A. & C. Black
Contributing Library: Gerstein - University of Toronto
Digitizing Sponsor: MSN

View Book Page: Book Viewer
About This Book: Catalog Entry
View All Images: All Images From Book
Click here to view book online to see this illustration in context in a browseable online version of this book.

Text Appearing Before Image:
imple measure-ment of this potential between the anode andcathode will give us an indication of the hardness of the tube. The scale isgauged according to the absorption of the X-rays by sheets of lead of differentthickness, increasing regularly from y^^ of a millimetre to 1 millimetre. No. 1 on the scale denotes X-rays of such a hardness as to be totally absorbedby /j- millimetre of lead. When the index is at No. 10 we know that the tubeis giving out rays which will penetrate 09 millimetres of lead, but will be totallyabsorbed by 1 milhmetre of lead. As already explained, the instrument is unipolar, being joined up by a singlewire to some point in electrical connection with the cathode. The instrument iscontained in an ebonite case, which swings freely from a bracket on the wall or astand, so as to be always in a vertical position. It should be within view ofthe operator, to enable him to estimate the hardness of his tube throughout thewhole of the exposure, without danger to himself.
Text Appearing After Image:
Fig. 187.—Bauer qualimeter.(Favre.) Comparative Scale of the usual Instruments for Measuring THE Hardness of Tubes hard soft medium Bauer .... 1 . 2 3 4 5 6 7 8 9 10 Wehnelt . 15 3 4-5 6 7-5 9 105 12 13-5 15 Walter .... 1 1-2 2-3 3-4 4-5 5-6 6-7 7-8 Benoist 1 2 13 4 5 6 7 8 9 10 THE THERAPEUTIC COIL 269 It is weU to have all these instruments—valve tubes, niiniamperemeter,qualimeter, and oscilloscope tube—in the circuit, especially when a greatdeal of work has to be done, as they facihtate speed in working, and enablethe operator to see that the conditions under which his work is being carriedout are correct. The Therapeutic Coil should be at least twelve inches spark-gap, andwhere more than one is possible a 16-inch coil should be installed. Anymodern coil is adequate, but the type Hkely to give the best results is one of spark-gap Milliamperemeter CoU enclosed Interrupter Rhythmeur

Note About Images