US 4,306,154 AGranted

Dosimeter

AssigneeThe United States of America as represented by the Secretary of the Army

InventorsEdward F. Williams, Jr., John B. Byer, Burton J. Thompson

Life of this patent

Estimating the term…

Loading patent…

Abstract

The construction of a direct reading, ionization chamber dosimeter is almost exclusively of thermoplastic material. Except for an electrometer frame and switch contacts, the dosimeter comprises components of injection molded thermoplastic material. The dosimeter barrel and most of the structural components are made from either electrically conducting polycarbonate or non-conducting polycarbonate. Optical parts and lenses are formed from transparent plastic materials. The ionization chamber is made from polypropylene loaded with carbon black. The light-weight plastic construction of the dosimeter renders it relatively insensitive to mechanical shock and causes it to interact with ionizing radiation in a manner substantially similar to animal tissue or human flesh.

Claims7

Dependent claims

In a dosimeter of the type comprising a tubular plastic barrel, an ionization chamber comprising an electrometer having a frame, optical means for viewing said electrometer, and means for charging said electrometer including a charging pin, all disposed within said barrel, the improvement comprising:

said ionization chamber except for said frame, said charging means except for said charging pin, and said optical means are of plastic materials,
said barrel comprises an electrically insulating upper plastic section comprising between 15% and 25% glass or glass fiber by weight of the plastic, and a lower electrically conductive plastic section comprising between 15% and 25% of either carbon black or carbon fiber by weight of the plastic sealed to said upper section, whereby said dosimeter is relatively light in weight, and is comprised substantially of plastic materials of chemical elements with relatively low atomic numbers so as to interact with ionizing radiation in a manner substantially similar to animal tissue or human flesh.

Dependencies are inferred from the claim text.