Optical alignment of parabolic trough modules

Based on the recently patented Visual Inspection Method (VIM), a new instrument, named Visual Inspection System Field (VISfield) has been developed and successfully tested on the PCS, the experimental parabolic-trough of ENEA Casaccia. The VISfield inspects one module (12 m length) at time, providing in less than two minutes: i) intercept factor (IF) map; ii) average IF, global and individualized for any facet mirrors; iii) adjustment at the fixing-points of any facet mirrors to improve its IF. Finally, after the alignment optimization, the refreshed IF map represents an useful tool to check the shape compliance of each facet mirrors. For that, VISfield completely satisfies item 2).