I have been testing some objectives for their UV transmission using LEDs as sources of radiation. I developed a protocol for such tests. Although used in this example to measure the spectral sensitivity of a camera sensor, the protocol can be easily adapted for the measurements of biological action spectra.
A draft report of these tests is available as an R notebook. This is an HTML file that can be viewed in a web browser. (The file is large, and takes some time to load.)
I thank Lasse Ylianttila for comments on an earlier draft of the linked report, and for our many helpful and entertaining discussions about all things “UV to IR”, including photography.