64 
BuL 2/1964 
Of the instruments or instrument combinations manufactured for these purposes at Oberkochen, 
viz. 
the PEK Monocomparator with 1 micron read-out of aligned figures and punch-card output, 
the PEK Monocomparator with second photograph for steroscopic comparison and identical 
motion range of principal and comparison photographs, 
the PEK Monocomparator with punch-card controlled setting mechanism, 
the PSK Stereocomparator with punch-card controlled setting mechanism, 
we shall throw a brief glance only at the latter (Fig. 5). The card punch C reads out the approximate 
coordinates of a fixed star, which are available in the form of punched cards. Two motors E are 
driven via the memory B, the coincidence unit C and the amplifiers D to set these coordinate values 
in the comparator. When this setting has been made, the handwheels F of the comparator are releas 
ed, so that the respective star can be optically measured with maximum precision by the operator. 
The „accurate“ coordinates thus obtained are transmitted to the automatic typewriter G and the 
card punch for printing and punching. As soon as this cycle has been completed, the next preset 
card is called in. The card punch is thus used alternatively for read-out and punching, each control 
card being followed by a recording card. 
Fig. 5 PSK Stereocomparator in connection with punch-card controlled setting mechanism. 
The saving in time thus achieved in the selection of the stars will be particularly noticeable in 
extensive ballistic measurements. With appropriate programming of operating cycles in the com 
parator, a comparison photo can, in addition, be called in via a functional key, which can either be 
viewed intermittently with both eyes or stereoscopically and which will further reduce the possi 
bility of setting errors, e. g. due to dust grains or faults in the emulsion.