Graphic Calculator Company Water Treatment Calculator

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Country of manufacture: USA,            Date of manufacture: >= 1946
Overall length: 17.4 cm,          Width: 6.1 cm.,           Weight: 37.8 gms
Materials: Plastic and cardboard
Cursor: 3.8 X 6.2 X 0.4 cm, plastic wrap-around;      Lines: one on front.
Scales: specialized
Front: F (CaCO₃ equiv. CaO Added), H (N.C. Hardness Removed), G (Mg(OH)₂ Made) [ E (Calcium Hardness), D (Mg Removed), B (CO₂) ] A (CaO & Na₂CO₃), K (Quicklime), M (Hydrated Lime)
Back: Instructions for use, S (Alkaliity) [ H (Free CO₂), T (pH at 25°.C) ] index mark, Instructions continued
Condition: C3 (Very Minimal Signs of Use)
Came with: Original cardboard box, instruction sheet

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