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AHREND (Wed. J. Ahrend & Zoon): 642T

AHREND (Wed. J. Ahrend & Zoon) 642T Rietz

Details of: AHREND (Wed. J. Ahrend & Zoon) - 642T

Type? A generic name (e.g. Rietz) or function/use for specialist models (e.g. Meteorology) for grouping similar models across makers. If not “standard” 25cm linear length, preceded by the form (i.e. Demonstration, Desktop, Pocket, Waistcoat, Keyring, Lilliput or Book) + if needed, qualification to distinguish between versions (e.g. early or late). Rietz
Sort? L/C/D/T/W/X where L=Linear, C=circular, D=Drum, T=tubular, W=watch, X=miscellaneous (i.e. the rest) L
Construction? Basic construction form of the body i.e. Closed/solid frame or Open frame or Duplex or Other Closed/solid frame
Material? Basic description: ivory/bone/wood/bakelite/plastic/metal/cardboard or combinations e.g. wood/veneered, wood/painted, etc bamboo/plastic/celluloid veneers
Length? Mostly the linear length of the D scale (in cm or inches) excluding any extensions. For circular/watch slide rules it is the diameter but for helical/tubular/drum slide rules it is the overall scale length. For other calculating aids it is the physical length. 25cm
Scales front? Standard (not maker’s) symbols for scales on front face e.g. A = X² (1-100) but § = generic symbol (signum sectiōnis) for any non-standard scale + scales between solidi / / are on the slide(s) whereas scales after vertical line | or after reversed solidus \ are on a straight or bevelled top or bottom side edge cm \ K,A / B,BI,CI,C / D,DI,L
Scales back? Standard (not maker’s) symbols for scales on back face e.g. S = sine (5° to 90° & 85° to 0°) or sin(x) but § = generic symbol (signum sectiōnis) for any non-standard scale + scales between solidi / / are on the back of slide(s) but scales listed after / / - notation are on another surface e.g. back of stock or inside a lid / T2,T1,ST,S /
Cursor type? Basic description (incl. material) + no. of hairlines, etc on any cursor(s) or alternative to a cursor - e.g. a stylus plastic - 1 hairline + 2 peripheral hairlines
Condition? Cn where n = 0-6  condition/quality scale where 0 = brand new in box & 6 = broken   C0
Date? YYYY for year(s) of production or an approximation/range of years 1973
Extras? Basic description of any accessories - e.g. case or stand + where relevant, an accreditation for image, etc Hemmi branded grey & blue hard plastic case, plastic bag & branded outer box
Instructions? Details like “on back of rule” and/or language of instruction sheet/booklet - generic or instructions for common layouts usually not listed English
Comments ? Any special or noteworthy traits + significant use-related facts + pertinent details of scales/tables in well of stock + any significant tables, etc on the back of the stock

OEM by HEMMI as wider version of 64T Extended Rietz + T model no. suffix possibly = basic 64 with extra Trig scales + table of constants & green pads on back + earlier thinner 64T sibling - also sold as Ahrend 643T

In-Out? MM-YYYY / MM-YYYY of the date added/left the collection or <YYYY if exact MM-YYYY no longer known <2005/

All of:  AHREND (Wed. J. Ahrend & Zoon) new search?

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