Kipp&Zonen CM 121 B/C Shadow Ring - Manual (Page 25)

6. APPENDIX
Instruction manual CM 121 24
The influence of the sliding bar parts rising above the horizon is neglected.
To compare: the formula for a flat shadow band is
S = 2W . cos3 . D . (U
0
. sinB . sinD + sinU
0
. cosB . cosD) / π. R (6.9)
W is the ring width and R is the ring radius. A comparison is shown in figure 6.
figure 6 the view angle of the U-profile shadow ring as a function of the solar declination, in
comparison to a conventional flat shadow band. It is shown that the CM 121B has superior
performance, as a result less seasonally variation of errors.