telae ttti 
a iu diit 
omi aua i nat c i 
   
10 
c) corresponding graphs could be drawn, based on equations (4) and (12), for 
the gimbal axis above the projection centre. ; T ems s 
b) Wild As. 
The same considerations as made for the A7 hold also for the AS. 
In the gimbal axis above the projection centre makes the primary axis an ang) 
508 with the x-axis. To obtain an equation for the projection errors, (1) i 
formed and rotated for 508. For both the gimbal axis in the projection ce 
the projection centre, the primary axis is parallel to x. (Different eccen 
e5, for the left and right projection bar respectively, have to be considered 
gimbal axis below the projection centre.) 
e of 
Must be trans. 
ntre and Belay 
tricities & af 
for the comm 
Conclusions: 
With respect to x- and y-inclination the same can be said for the A8 as 
the AT. In particular, the: diagnosis will be, if a 9- or much better 
shows: 
applied 4 
a 20-point Measurement 
a) fig. 7, 8 or 9 — errors in either the gimbal axis in the projection centre or bel 
projection centre; 
b) corresponding graphs could be drawn for errors in the gimbal axis above th 
tion centre. 
OW the 
€ Proje 
€) Zeiss Stereoplanigraph C 8. 
1. Gimbal axis below the projection centre (mirror). 
A cross is engraved on the mirror. The cross must be in the gimbal centre, The il 
minated floating mark is made to coincide with the cross. 
[i 
  
  
     
   
  
   
z oy. 
| L I I I b i pex | zr 
| i 
y 
| A 
| 4 
a 
| 
“8 
a 
Lut à 
Fig. 14 Fig. 15 
The assumed situation is demonstrated in fig. 14: The primary and secondary rotatil 
axis do not intersect; the cross K of the mirror M is off the secondary axis, indicated lj 
the components e,, e, and e,. 
The derivation of the required equations will be made for the left mirror only. Fy 
15 shows the zero-position K’ of the mirror. A rotation of 508 around the secondary als 
is introduced; a — 0 and f — 0. The principal point has been centered onto the ze" 
position K’ by means of moving the projection lens in x and y directions. Likewise ti 
illuminated floating mark has been centered onto K'. 
A. rotation a around the primary axis has been made in fig. 16. We get 
rr 
Az, = 2", = cosa (e, cos 50 + e; — ey sin 50) + e, sina 
AY 
T yg YQ» 7 Sina (e, cos 50 -- e, — e5sin 50) -- e, (1 — cosa). 
  
  
  
    
  
   
   
   
    
   
    
  
    
   
   
    
   
   
  
  
   
  
   
  
   
   
  
   
7" 
| 
é 
| 
d M 
The projection 
jy = BB" - 
] 
pi e € 
"e co 
À section 
pound the seco 
Agi, zm zl 
AI T e 
With respec 
Mark we get fr 
A = A 
The vertical dis] 
02 = A In“ - 
lh e sin 
TE,