to this program, the spectral resolution is driven instead by the spectrograph aperture size and filling factor. We are primarily interested in the LWRS (30 square) apertures for this paper. A filled LWRS aperture produces a roughly square-topped instrumental profile of width 106 $\VEL$ near 1035 Å. $\fuse$ contains four optical channels, each with its own focal plane and spectrograph aperture plate.

Small, thermally-induced distortions in the $\fuse$ optical bench discovered after launch do not allow rigid co-alignment of the apertures from each channel over time. Typical misalignments correspond to a few to as much as 10, and can vary even during the course of a given orbit or integration. For reference, the LiF1 LWRS aperture positions are shown in this paper. The LiF1 channel was used for guiding, and so its position on the sky was held fixed while the other channels drifted relative to it. In cases where the object is large in comparison to the $\fuse$ apertures, all of the apertures should be sampling similar SNR emission. However, on the smaller objects, channel misalignments can cause different sampling and impact the assessments of relative O VI and C III line strengths. Further details about the $\fuse$ instrument 