Rachel McQueen, Camilla

Nominally each Ring heater lower segment has a RTD temperature sensor on it. These our the closest temperature sensors to the quad, in alog 46791 Aidan shows them witnessing LVEA temperature changes. Giving this status update as Rachel is looking into these sensors as part of her summer SURF project.

This is the current status of the sensors at LHO is below: only ETMX has a readback but this sensor is not attached correctly to the assembly.

• ITMX - Cable broke at sensor, free cable secured alog 9992, FRS 10482 c18
• ITMY - Was pinched and stopped working during ITMY swap Dec 2020 57519, see attached plot.
• ETMX - Not connected to structure, FRS 10482 c14, but otherwise reading back well..! Currently reporting 277K (39degF, 4degC) plot attached where you can see temperature change ~0.5K with each lock cycle.
• ETMY - Reported broken T1800421 suggests due to C&B or install. 2012 alog 3429 and 2018 alog 45187.