Optical Tests on a Curve Fresnel Lens as Secondary Optics for Solar Troughs

Table 3

Concentration factor C as a function of α for lens_C.

α (°)	mm	mm	mm	mm	mm
40	1.88	1.98	2.02	2.03	1.97
35	1.90	1.98	2.03	2.05	2.01
30	1.91	1.99	2.04	2.05	2.02
25	1.92	2.00	2.04	2.06	2.01
20	1.91	2.00	2.04	2.05	2.00
15	1.88	1.98	2.02	2.05	2.01
10	1.87	1.97	2.01	2.01	1.98
5	1.87	1.95	1.99	2.00	1.96
0	1.92	2.02	2.06	2.08	2.03
−5	1.95	2.06	2.10	2.11	2.07
−10	1.97	2.07	2.12	2.14	2.09
−15	2.01	2.11	2.15	2.14	2.10
−20	2.03	2.13	2.16	2.14	2.09
−25	2.05	2.13	2.16	2.15	2.09
−30	2.05	2.12	2.14	2.14	2.11
−35	2.03	2.10	2.15	2.18	2.08
−40	2.05	2.14	2.16	2.15	2.10