I had to tag Jeff on this one to run the long_trend.m because I had nds2 troubles. Jeff ran it with no problems...
He also mentioned that we may need to flip the bias soon on ETMX because (let's see if I understood this correctly) the angular actuation is off by ~8% in some quadrants, but the longitudinal is only off by ~3% (See summary screenshot).
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jeffrey.kissel@LIGO.ORG - 15:19, Wednesday 22 March 2017 (35016)
Sorry abandoning TJ quickly on this one. Here's what I said in regards to these plots:
Last week, I'd threatened that we needed to flip the ESD bias sign on ETMY because the traditionally posted angular relative actuation strength plots continue to show changes at the level of 8-10% because appreciable effective bias voltage from charge (negative 20-30 V) is accumulating in some quadrants. Note that this is relative to zero effective bias voltage.
However, if I look at the summary pages, to show me the longitudinal relative actuation strength (the fifth plot that TJ posts) as measured by the PCAL and SUS calibration lines -- the actuation strength direction that actually matters for calibration -- it shows a level of 3-4%. Note that *this* is relative to the latest calibration reference model, created Jan 4th, when the effective bias voltage was already in the negative 10 V range.
In summary -- I don't think we're in dire need of a bias flip on ETMY any longer. But we remain dilligent!
I had to tag Jeff on this one to run the long_trend.m because I had nds2 troubles. Jeff ran it with no problems...
He also mentioned that we may need to flip the bias soon on ETMX because (let's see if I understood this correctly) the angular actuation is off by ~8% in some quadrants, but the longitudinal is only off by ~3% (See summary screenshot).