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Calibration facilities

The UES A&G unit provides a range of comparison lamps (both emission line and continuum), and neutral density, polarizing and colour filters. The UES Manual gives a full listing. The present set of neutral density filters is known to introduce a ripple in the signal at a level of a few percent peak-to-peak; possible replacements are currently being considered. Wavelength calibration normally uses a Th-Ar hollow-cathode reference lamp.

Tue Aug 15 16:42:46 BST 1995