52 
É I 
Fig. 1 . Anal prêt plotter Cexperimental type} . 
The Concept and Realisation 
uses the PC 
contr ol1ing 
considered as 
for teaching and 
attached as slave, 
a work station by 
The plotter imagined wa 
representative of low cost instruments 
analytical interpretation. It 
communicating with the host 
standard serial lines. 
The measuring system follows the classical 
Pulfrich stereocomparator idea with line encoders for X and Y 
axes with 5 micrometer incremental resolution. The image 
carriers are moved by freehand, but fine movement may be made 
with pointing screws, if neceEsary. 
The Px movement of the right image is controlled by screw and 
the impulses are given with circular encoder with 0.01 mm 
increments. The ranges of X, Y are 300 mm and 250 mm 
respectively. The measuring range of Px and Py is 50 mm. 
A stepper motor has been applied for Py movement of 
the right image carrier with 5 micrometer distance increments 
related to the picture. 
The digital counter for X 
serve to adress the two pedals 
pi otter. 
Further two PCB were put into 
software serves for calling 
Y and PX and the circuits 
has been built into the 
the PC 
pi otter 
and machine 
coordinates 
code 
and 
controlling stepper motor for movement and counting