Today at 15h UTC, the first calibration period of O3 was started. The updated procedure was followed by Andrea M., and we improved a bit the procedure accordingly.

In addition to the standard measurements, two additional actions were performed:

• move the LED used for PCal timing calibration on the NE and WE PCal reflection benches (around 16h45-17h45 UTC).
• add injections to measure the finesse using the PCal and DARM injections (will be added to the standard measurement, 1 minute)
• inject with the NE NCal around 19h30-19h45 UTC.

Some injections lasted for longer time than expected. We will tune them for next Wednesday to reduce a bit calibration duration.

The measurements with ITF unlocked lasted for about 1 hour, so the relock from cold ITF was a bit long, and relock failed at first attempt. We modified the calibration sequence in the procedure to relock the ITF (for InToEnd calibration) between the unlocked measurements, to have an intermediate relock, between two shorter unlocked periods.