16864

The IR grism flux monitor shows a sensitivity loss of 0.12+--0.01%-yr in G102 and 0.06+--0.01%-yr in G141. Observations of flux standards in the IR filters comma however comma show no evidence of any loss over time comma but the repeatability is limited by systematic errors of +-- 1%. Scanned observations of M35 from 2015-2020 show marginal losses of 0.024+-- 0.008%-yr in F140W comma but these data show a large scatter which may be related to detector preconditioning. Cluster observations allow for the measurement of many more stars comma and photometry of the core Omega-Cen used for distortion monitoring suggests losses of 0.23 +-- 0.03%-yr in F160W comma but crowding may play an effect on the results. Recent observations of a less dense stellar field in M4 in F110W suggest losses of 0.13 +-- 0.02%-yr (first images only) and 0.20 +-- 0.03%-yr (all images) comma but these consist of only 4 visits. We propose continued monitoring of M4 at a virgul6 month cadence. Two additional clusters are requesteddoublePoint the NGC104 field 6. from the core with F160W data from 2009-2013 and an Omega-Cen field 17. from the core with F110W and F160W images from 2016-2018 comma both of which mimic the observation strategy from the respective preceeding epochs comma to eliminate systematics from differing observing modes.