Thanks to Deon & Garith for help with our various software issues today!
& to Keith for getting our new LEDs rigged up for the throughput testing.
The test rig consists of a stabilised power supply to feed the various LEDs (right), a pinhole & a set of lenses to image the pinhole onto the fibre (which attaches at the left-hand end). The fibre gets replaced with a calibrated photodiode connected to a pico-ammeter for the calibration process.
One can view the spot on the fibre using a small finder telescope with a penta-prism on the end to peer into the beam.
Here's the fibre end in its brass ferrule, mounted in an adjustable stage assembly.
The photodiode has a well-defined spectral response which can be compared to the total signal recorded on the appropriate HRS CCD.
This all looks like it's going to work so more on throughput tomorrow! For now though, we're in some form of spectrograph assembly withdrawl so Luke brought his bicycle bits out into the lounge this evening.
& regaled us with the full run-down of all the special features.
Even the super-stylish wasp-magnet helmet made a brief appearance!