Chapter 13: Spectroscopic Reference Material 13.1 Introduction 13.2 Using the Information in this Chapter 13.2.1 Grating Parameters 13.2.2 Wavelength Ranges 13.2.3 Grating Sensitivities and Effective Areas 13.2.4 Signal-to-Noise Plots 13.3 Gratings FUV Grating G130M FUV Grating G130M with CENWAVE=1222 FUV Grating G130M with CENWAVE=1055 or 1096 FUV Grating G160M FUV Grating G140L NUV Grating G185M NUV Grating G225M NUV Grating G285M NUV Grating G230L 13.4 Spectrograph Design Parameters 13.4.1 FUV Channel 13.4.2 NUV Gratings 13.5 The Location of COS in the HST Focal Plane 13.6 The COS User Coordinate System