Abstract
Elmer is a visible imager and spectrograph for the GTC. Elmer Optics has been exhaustively tested at different steps, from the blanks to the final assemblies in order to guarantee the fulfillment with the required performance. In this contribution, we describe the tests done to the different optical components until now. Blank testing, WFE Image quality and Transmission tests have been carried out in most of the components, as well as some tests of the complete optical system integrated on the instrument structure.
