Full Details

Name and Model Number Aristo 630 Chemie
Country of Origin Germany
Date of Manufacture  
Front Scales C [D, 6 specialised scales]
Back Scales None
Scale Length 22.0 cm diameter
Type of Rule Slide Rule
Construction Plastic
Area of Use Chemical
Rarity RRR
Donor Collection of Rod Lovett
Match Number 3

RR = Rare -- 1 of 25 collectors has one; it may take a year to find an example in the marketplace.   
RRR = Very rare -- only very few known to collectors; may take several years before one comes up for sale.   
RRRR = Extremely rare -- a museum piece; unlikely that an example will ever come up for sale.