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NESTLER   »ELEKTRO «   Model 37
Version (C)   ( 25 cm Scales )





Have a look at  OLDER VERSIONS
Albert Nestler, Lahr in Baden / Germany                 (1945)
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                                                   VERSION (C)

S C A L E S  of  the   NESTLER   » E L E K T R O «    Model 37
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Front Side           [ inverse / RED ]               Back Side
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( 0 .. 25 cm Ruler )

     V       X * 1.75
(A)  PS      X2
--------------------------------------------------------------
(B)  KW      X2                           S         sin(0.1X)
[CI]         [1/X]                        S&T       arc(0.01X)
(C)          X                            T         tan(0.1X)
--------------------------------------------------------------
(D)          X
     U       X * 5.24
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(LL2)        exp(0.1X) = keyed to SCALE A and LEFT CURSOR-MARK
(K)          X3

The Slide Rule is LONGER  and has a  30 .. 56 cm RULER IN BASE

R E M A R K S :                     (  1° = 60' ;   1' = 60" )
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The  TRIGONOMETRIC SCALES  are  divided  in  MINUTES & SECONDS

The no-named scales are marked here with their common symbols
in brackets: (A),(B),(CI),(C),(D),(LL2),(K).

The U-Scale is folded by ( for calculating "Revol./Minute" )
    π / 60  =  0.05236
The V-Scale is folded by the "Specific Resistance of Copper"
    sRcu  =  0.0175 Ω * mm2 / m
The CU-Marks  for  "Specific Conductivity of Copper"
    sCcu  =  57.2 m / Ω * mm2  =  1 / sRcu
The 736-Mark  for
    1 PS  =  0.7355 kW  with "Effectiveness"-Marks for
    MOT (=Motor) & DYN (= Dynamo)
The Mark  sqrt(2g) = 4.429  for  "Pressure Hight" calculations

There are 3 different Versions "Model 37" in this collection

In this VERSION (C) the Inverse Scale [1/X] is added ...
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The  CURSOR HAIRLINES  are symmetrical and in the common
distance (on A-Scale) AREA/DIAMETER (on X-Scale).
The LL2-Scale is placed  OVER  the CUBIC-Scale and SHIFTED,
that CUBIC "52" is under LL2 "e"  = 2 CURSOR SIDE-Hairlines.

Have a look at  VERSION (A)  &  VERSION (B) ...

Historical Remarks ...

The slide rule came in a black cardboard case. It is made of
mahogany with scales on celluloid veneer.  The back side's
table with constants was in good shape.

impressum:
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© C.HAMANN     http://public.BHT-Berlin.de/hamann      10/10/10