Ratio of the normalizations of the O vii Heαr, O viii Lyα line, Ne ix Heαr, and Ne x Lyα line compared to the IACHEC model value as a function of time for ACIS-S3 subarray observations near the aimpoint with the contamination model N0009 in CALDB 4.6.2. The different symbols indicate data collected in different nodes on the CCD. The solid, black line is the IACHEC value (normalized to 1.0), the dashed, red line is the average for each line normalization, and the black, dashed lines are ± 10% of the IACHEC value.