Grating information from Resonon

Email info from Hans (Nov 2019)

All of the gratings for the Red spectrometers come from the same batch, produced by Wasatch Photonics.  The Blue spectrometer gratings are from two batches, both produced by Kaiser;  four gratings in 2014 and two in 2016.  I'm having trouble digging up the exact delivery date of the gratings for the Red spectrometers; however, we received the quote for this batch in Feb. 2015.  I've uploaded a test report for a Red and a Blue grating to the above link.