4.1 Overview

In this chapter we describe various properties of the COS detectors that affect the final quality of the science data products, in particular the various sources of error affecting the accuracy of the flux-calibrated and wavelength-calibrated spectra. Note that several of the effects outlined below are the subjects of ongoing study.

Always check the COS Web pages for the latest Instrument Science Reports (ISRs) which describe the results of various studies intended to better characterize COS.