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SIEMENS  &  HALSKE
LAB   PRECISION   WATT - METER



Beside the contemporary   F.-C. »COLUMBUS«   (= 38 cm / 15" )   SlideRule

LAB  PRECISION   W A T T - M E T E R   SIEMENS & HALSKE / Germany (1900)
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Width = 23 cm / 9" ;  Depth = 32 cm / 12_1/2" ;  Height = 12 cm / 4_3/4"

SCALE  =  0 .. 150                                          SN = 2803243

       =  1 kΩ ;    25 A ( 7 mΩ ; 20 μH )    /    50 A ( 1.7 mΩ ; 5 μH )

Results from  T E S T S  ( see below):
======================================
MAXIMAL:   ( DC / AC )  1500 W   =   ( 300 V * 5 A ) ... ( 30 V * 50 A )

CALIBRATION FACTORS:     » 25 A «   =  x5    /    x10  =   » 50 A «

VOLTAGE-INPUT on the BLACK CLAMPS ;  the  CURRENT-INPUT on BRASS CLAMPS.
The SWITCH on front  changes the POLARITY  for the instrument ;  and the
SCREW above is for  ZERO-ADJUST  of the instrument.  The BRIDGES have to
be set either to  » 25 A « (shown)  or to  » 50 A «.

( ... left the FABER-CASTELL Ebony-SR  » COLUMBUS «  to compare sizes !)

Some  T H E O R Y ...

  

... adapted from O.MOHR
"Elektrotechnik"
(1961)




Picture from
"Kleine Enzyklopaedie"
TECHNIK
(1956)




A Look I N S I D E ...

     

   

... and  a  F R O N T A L  View  shows  the  BRIDGING INSTRUCTION ...

   

T E S T I N G  THE  INSTRUMENT ... 

       Bridge to  » 25 A «
       -------------------
    o   12 VDC /   18 W  LAMP    ===>>    showed    3.5  on Scale

    o  220 VAC /   25 W  LAMP    ===>>    showed    5.0  on Scale
    o  220 VAC /   40 W  LAMP    ===>>    showed    8.0  on Scale
    o  220 VAC /   60 W  LAMP    ===>>    showed   12.2  on Scale
    o  220 VAC /  100 W  LAMP    ===>>    showed   20.0  on Scale
    o  220 VAC /  200 W  LAMP    ===>>    showed   40.0  on Scale

                                           ===>>   CAL.FACTOR  x5
       Bridge to  » 50 A «                         ==============
       -------------------
    o  220 VAC /  100 W  LAMP    ===>>    showed   10.0  on Scale
    o  220 VAC /  200 W  LAMP    ===>>    showed   20.0  on Scale
    o  220 VAC / 1000 W  HEATER  ===>>    showed  105.5  on Scale

                                           ===>>  CAL.FACTOR  x10
                                                  ===============

===>>  The  R A N G E  of this Precision Instrument  is   5 W ... 1500 W
                                                          ==============

Maximal:   ( DC / AC )  1500 W   =   ( 30 V * 50 A ) ... ( 300 V * 5 A )

                Have a Look at a Modern Version ...
                Have a Look at a home-made TEST-UNIT ...
impressum:
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© C.HAMANN      http://public.beuth-hochschule.de/~hamann       11/11/11