OEM by ARISTO with Aristo Commerz I in well + Ahrend co-branding with model no. in back

OEM by ARISTO + reversed inch scale, cursor window with 1 hairline, Ahrend branding & closed Dutch industrial motor manufacturer De Industrie in back

OEM by ARISTO + reversed inch scale, cursor window with 1 hairline & Ahrend branding in back

OEM by ARISTO with Aristo-Rietz & D&P in well + inch scale & Ahrend co-branding with model no. in back

OEM by ARISTO with Aristo Studio & Ahrend No. 694 co-branding on front

OEM by ARISTO with Aristo-Commerz on front + Ahrend co-branding with model no. in back

OEM by ARISTO with Aristo MultiLog + Ahrend 703 co-branding on front

Extra wide ​- see also smaller siblings & pocket sibling

Extra wide + Multilog v/s Studio = extra LL00 & LL0 scales - see also smaller sibling 

Leading zero in model no. seems out of place + probable promotional give away as I.E.O. Breda printed in gold on case  

Part of a Schools & Vocational series but later version with additional K scale

Part of a Schools & Vocational series

Part of a Schools & Vocational series + LL suffix = Log Log + version without BI & LL1 scales but with cm & inch scales on back

Part of a Schools & Vocational series + LL suffix = Log Log + later version with additional BI & LL1 scales

Part of a Schools & Vocational series + version with a more Rietz layout (e.g. L scale at top) but without later additional BI scale + cm & inch scales on back

Part of a Schools & Vocational series + later version with additional BI scale 

Part of a Schools & Vocational series + early version with simplex cursor + VS suffix = “Verschoben Skalen” or folded DF & CF scales

Part of a Schools & Vocational series + early version without BI scale + VS suffix = “Verschoben Skalen” or folded DF & CF scales + -2 suffix = second issue of VS model now with duplex cursor 

Part of a Schools & Vocational series + LL suffix = Log Log & Bi prefix = an S scale on stock & slide - see also demonstration slide projector sibling

Part of a Schools & Vocational series + early version with T1 & T2 scales

Later reissued with amended layout as MultiTrig version 

Reissue with amended layout of earlier MultiRietz version

Later version has T1 & T2 scales

Earlier version has no T1 & T2 scales

Extra wide body & impressive complement of scales

Extra wide + Multilog v/s Studio = extra LL00 & LL0 scales - see larger desktop sibling 

Rich complement of scales

Overhead projector version for model 0901 - see also Classroom version - part of a Schools & Vocational series

Series of imperial to metric conversion gauge marks on lower front face - s-d-£ scale is folded - inch scale on back - 25cm (no. 955) & 12.5cm (no. 845) versions also made ​

Co-branded D&P name in well of stock - ​inch scale on back

​inch scale on back

Co-branded D&P name in well of stock​

Overhead projector version for models 868 & 0968 - Studio = range for more technical disciplines

44nd anniversary gift from Ros - boxed set of two lantern slides specifically for manual feed 35mm photographic slide projector - BiScholar = range where a Sine scale is included on stock & on slide - see also standard 0906 sibling

Later Classroom version for model 0901 - see also OHP version - part of a Schools & Vocational series

Later Classroom version for model 0903 LL - Scholar = general schools range

Mark-up & discount percentage scales

For calulating speed, time, distance & fuel consumption + Co-branded D&P name on back

Mini finger holes to help turn inner disc

Good for basic calculations but missing Trig scales 

Layout festooned with guage marks for imperial weights & measures 

NSU = German motorcycle & later car manufacturer - conventional time-speed-distances for motorists with km/hour on front & metric fuel economy Litres/100 km on back + B&W version also made & sibling 671 model calibrated for imperial miles & gallons ​

Gets its Mono name from all scales on front face + chrome pouch clip … read more 

1 mini-cursor window in back

Co-branded D&P name in well of stock + mini-cursor window & CALTEX branding in back

Unusually W & V scales on front face

Unusual stripped down cheaper version of 867 U (hence box + instructions) reputedly for other companies/makers to add their own branding 

Aristo Darmstadt printed on back

Aristo Darmstadt & Dennert & Pape Hamburg printed on back

See also larger siblings & desktop sibling

See also larger siblings & desktop sibling

Cursor window + 1 hairline & company logo for German-based company Nilos producing conveyor belt equipment in back

Inch scale + cursor window + 1 hairline & sieve size table for defunct German wire weaving company F.  Oberdorfer in back

Compared to sibling twin model 89 has magnifying cursor & peripheral hairlines  

V & W scales in well + inch scale on back + Aristo (well) & D&P (back) co-branding - later replaced by 915

Replaced 914 + rubber feet on back

Pipe flow calculations based on simplified Kutter formula with n=0.35 circular and ovoid sewers with h/b = 3/2

Version for 1200 - 2600 range + Table of factors & pictograms on back

Extra wide body & very complex to use + Table of factors & pictograms on back

PRAKTIKER & Dennert & Pape Hamburg in well + inch scale on back

Early version with unusual edge scales & without D scale added to later version  

Later version with additional D scale

Multilog v/s Studio = extra LL00 & LL0 scales - see also larger sibling

Standard all white closed frame plastic back plate with 2 cursor windows but other versions had clear plastic back plates 

Clear plastic closed frame plastic back plate making cursor windows superfluous - other versions had all white plastic back plates  

100% Geretsried made dummy - slide does not slide - “Ausstellugsmuster” on back

100% dummy - slide indented but does not slide - “Ausstellugsmuster” on back

Non-programmable with 9-digit display

Non-programmable with algebraic data entry & 12-digit display

Possibly transitional example before moving to Astralon & Aristo branding + owned by Emiel Gibas

Impressive layout of 26 scales - Neper or Np is a logarithmic unit of measurement of physical field & power quantities -+ see comparable sibling model 690 - comparable to ARISTO 0968