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REISS - DUPLEX   ( 25 cm Scales )



REISS, Bad Liebenwerda / (GDR) Germany                     (1970)
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                                                      VERSION (A)

SCALES of the  R E I S S (DECELITH)  » D U P L E X «   Model 3227
=================================================================
Front Side             [ inverse / RED ]                Back Side
=================================================================

[LL00]     [exp(-0.001X)]       K        X3
[LL01]     [exp(-0.01X)]        T1       tan(0.1X)
[LL02]     [exp(-0.1X)]         T2       tan(X)
[LL03]     [exp(-X)]            [DI]     [1/X]
DF         πX                   A        X2
-----------------------------------------------------------------
CF         πX                   Sh1      SinH(0.1X)  <0.1 .. 0.9>
[CIF]      [1/πX]               Sh2      SinH(X)      <0.85 .. 3>
[BI]       [1/X2]               Th       TanH(0.1X)    <0.1 .. 3>
[CI]       [1/X]                Sz       sin(0.1X)
C          X                    C        X
-----------------------------------------------------------------
D          X                    D        X
LL3        exp(X)               Sk       sin(0.1X)
LL2        exp(0.1X)            [P]      [sqrt(1 - (0.1X)2)]
LL1        exp(0.01X)           ST       arc(0.01X)
LL0        exp(0.001X)          L        lgX

R E M A R K S :
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With its 30 scales it belongs to the most »loaded« slide rules!

The DEFINITIVE FORMS for the HYPERBOLIC FUNCTIONS are:

CosH(X) = ( exp(+X) + exp(-X) ) / 2   <==   "Chain Line"
SinH(X) = ( exp(+X) - exp(-X) ) / 2   ( eg. suspension bridge )
TanH(X) =  SinH(X)  / CosH(X)
 exp(X) =  SinH(X)  + CosH(X)
      1 =  CosH2(X) - SinH2(X)

CosH(X) =  SinH(X) / TanH(X)  =  sqrt( 1 + SinH2(X) )  =  H(X)

Using the Hyperbolic Functions:
Start with value on the Sh scales ==>> reading SinH on C scale,
  start with value on the C scale ==>> reading ArcSinH on Sh.
Start with value on the Th scale  ==>> reading TanH on C scale,
  start with value on the C scale ==>> reading ArcTanH on Th.

Historical Remarks ...

Remarkable is (on the right lower corner) »GERMANY« (NOT »DDR«)

There is a NEWER VERSION (B)  in the Collection:
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Details of the Front ...

(a)
More SCALES have "OVER-LENGTHS" right & left and on Front & Back
(b)
The >1< in CF/DF & C/D is marked
(c)
The Trigonom.Expressions have Arguments "x"
(d)
The FIGURES of L-Scale are right of its ticks  (in Vers.A = left)
and the L-Scale ends in ".0"  ( in Vers.A in "1.0" )  
(e)
Smaller FONTS in "DUPLEX", "REISS", "3227" & "Made in Germany"

impressum:
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© C.HAMANN      http://public.BHT-Berlin.de/hamann       02/11/13