Faber-Castell Duplex 2/82 & 62/82
Faber-Castell slide rules quality is well known among users and collectors. Here are the Duplex /82 models: 2/82 (13 inches long) and 62/82 (7 inches long). This model was produced in the 1950's and 1960's. Fabricated all plastic with 24 printed scales, -12 on each side-, all plastic cursor, and hold with metallic braces, was used mainly by scientists and engineers.
Additional to the Mannheim standard scales, this model had six Log-Log scales, the Pythagorean P-scale, and two scales for the Tangent function, plus two special cm-inches scales. On the Main side are the scales: cm, T2, T2, A-B, BI, CI, C-D, P, S, inch. On the back side are the scales: LL01, LL02, LL03, K, K', L, ST, CF-DF, LL1, LL2, LL3. One special characteristic of Faber Castell rules is its self-documenting scales, this is, its mathematical formula (with order of magnitude) appears at the right end of the scales.
Faber- Castell fabricated a clone of Model 62/82, for Dietzgen, the MultiLog 1778.
With these nine scales, an skillful slide rule user is able to perform the next Math operations, with two-three decimals precision:
Next is a scan (not very good... sorry) of the user manual for the Duplex 2/82 and 62/82. Again is remarkable the simplicity of the manual for this complex model:
Click on the next links to see professional panoramic pictures of the 2/82 and 62/82 models.
Note: The models in the panoramic pictures do not have the cm-inches scales. The picture of model 2/82 is of the first version of these model with 22 scales only. All other scales are identical and at the same location. The picture for the 62/82 includes the cm-inches scales
References:
Smith Hughes, Richard: Watch your Ps and Qs -The Pythagorean Scales- Are They Worth the Effort? Journal of the Oughtred Society, Vol 15, No.2, 2006. https://osgalleries.org/journal/pdf_files/15.2/V15.2P50.pdf
Holland, Peter: Rechenscheiber/Slide Rule. A.W. Faber - A.W. Faber-Castell. Modelle, Typen, Skalen/ Models, Types, Scales. 2020 Digital Edition V 8.0. (This an extensive reference of Faber Castell rules models) Rechenschieber von Faber-Castell (sliderulemuseum.com)