File:Radiography, x-ray therapeutics and radium therapy (1915) (14570852209).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

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If the tube flickers with a contact of a certain size, 22 RADIOGRAPHY the tube may be steadied by increasing this contact. This flickering maybe also due to the motor of the interrupter running slowly. Another reasonfor this effect in the tube may be the piercing of the condenser, and thiscan be detected by testing the spark length of the coil. If one cannotobtain the full spark length and the primary current is above the normal,then the condenser should be carefully examined. Finally the coppercontacts of all interrupters need replacing from time to time, as they becomeburnt through from long usage, this leading to bad and intermittent working. Improved Mackenzie Davidson Interrupter.—This is a usefulform of mercury interrupter when an outfit of moderate capacity is all thatis required, and when accumulators are used as the*source of supply. It consists of a metal pot containing a supply of mercury into whicha contact set at an angle dips. This contact is mounted on the end of the
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Fig. 18. — Improved Mackenzie Davidson interrupter. (Scball.) shaft of a motor whose speed can be varied in order to vary the numberof interruptions. This interrupter requires rather more mercury than mostof the other types. Electrolytic Interrupter.—This type was introduced by ProfessorWehnelt. The principle of construction is simple. A platinum wire and alarge lead electrode are immersed in diluted sulphuric acid in the proportionof acid 1 oz. to 5 oz. of water. This interrupter is without doubt a good one, far exceeding the bestmercury interrupters, not only in regard to output and capacity for regula-tion, but also in simplicity of construction and use, as well as in safety ofworking. Wehnelt interrupters can be used wherever continuous currentis supplied direct, i.e. from supply mains, accumulators (at least about65 volts), or a motor generator, or where single-phase or three-phase currentis converted into continuous current by means of rotary converters or ELECTROLYTIC INTER

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