Quality control

The calibration plan for FIES has been expanded to include a test for light pollution. It has repeatedly happened that when working on the dewar or the controller of the CCD LEDs and/or the controller display inside the white box were left without being taped off. This gives rise to low-level (about 10 ADU in 300 sec) diffuse scattered light on the red side of the CCD when exposed with the shutter open which will be visible in longer exposures of fainter target.

A test has been added that makes a 300 sec exposure with the dome- and calibration-lights switched off. The test should be run every time electronic components have been changed (controllers, pressure sensor, etc.), or in general when the CCD controller has been touched.

We still need to make an automated temperature-stability analysis tool based on shifts of the Echellogram. In connection with this, a script will be created that checks for changes in ThAr line-ratios in order to detect the ``dying-lamp'' phenomenon. A database will be made of the results to monitor the calibration lamps.

Thomas Augusteijn 2012-02-21