Aristo Hyperbolog Nr. 0971
The Hyperbolog 0971 was produced in Germany from the mid 1950's until the early 1970's. Fabricated with high grade PVC (Astralon/Aristopal), plastic braces, and all plastic cursor with four gauge lines for quick HP-KW conversion, is a great slide rule for electrical engineering applications, incorporating to the standard logarithmic and trigonometric scales, hyperbolic sine and tangent scales.
This rule has 25 scales: Th, K, A [ B, T Cot, ST, S Cos, C ] D, DI, Sh2, Sh1 on the front face, and LL01, LL02, LL03, DF [ CF, CIF, L, CI, C ] D, LL3, LL2, LL1 on the back face. Something noticeable is the lack in this scales set of the Pythagorean Scale P, so characteristic in the Aristo slide rules.
According with the engraved serial numbers on the specimen shown below, this was fabricated in 1969 in Hamburg:
The next problems can be solved with a precision of two-three decimals using the 0971:
SRPractice-3.pdfHere is a scan made by ISRM of the 0971 user manual:
Aristo_971Hyperbolog_972Hyperlog Instructions.pdfI'm including this scan of the 1955 Aristo Products Catalog shared by Murray Felstead, a friend of the Slide Rule Fan Club in Facebook
ARISTO-1955-ProductCatalog.pdfClick on the next links to see professional panoramic pictures of the 0971 model.
https://www.sliderulemuseum.com/Aristo/Aristo_0971_Hyperbolog_dc2FX4.jpg
References:
Mosand John: A Brief History of the Aristo Studio Slide Rule. http://www.oughtred.org/jos/Mosand_BriefHistoryOfTheAristoStudioSlideRule.pdf
Aristo: Product Catalog 1969: https://drive.google.com/file/d/1il3ty5j3n2rC4mHHBqag1jX788X1EmNd/view?usp=sharing
Aristo-Werke, Denert & Pappe KG: 100 Years of Aristo Slide Rules 1872-1972, Hamburg. 1972. https://drive.google.com/file/d/1AYMhF20TCHU_nUQLkx0RaJ9pNK1vTyic/view?usp=sharing
Robinson, William K: LISTING OF ALL KNOWN SLIDE RULES WITH HYPERBOLIC SCALES, www.oughtred.org/jos/robinson-hyperbolics-dec06.html