Radium Chemical Company Radiation Exposure Calculator 1948

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Country of manufacture: USA,            Date of manufacture: ____
Diameter: 15.0 cm,      Weight: 64.3 gms
Materals: plastic discs
Cursor: one-sided plastic, one line.
Scales: 7
Front:
     Outer Disk: Exposure Time
     Middle Disk: Thickness of Steel in Inches, Film to Source Distance in Inches
     Inner Disk: Film Speed Factors, Milligrams of Radium, Instructions
Back:
     Outer Disk: Density Scale
     Inner Disk: Thickness of Material Scale Inches, Instructions
Gauge Marks: [ ]
Condition: C3 (Very Minimal signs of use)
Came with: Original black leather case

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