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Entry  Fri Aug 30 17:31:56 2019, anchal, DailyProgress, TempCtrl, Vacuum Can Temperature Control Setpoint Step Test 
    Reply  Wed Sep 4 11:04:08 2019, anchal, DailyProgress, TempCtrl, Vacuum Can Temperature Control Setpoint Step Test - Results VacCanStepResponse.pdfVacCanStepResponseFit.pdf
       Reply  Wed Sep 4 11:49:02 2019, rana, DailyProgress, TempCtrl, Vacuum Can Temperature Control Setpoint Step Test - Results 
          Reply  Thu Sep 5 11:15:06 2019, anchal, DailyProgress, TempCtrl, Vacuum Can Temperature Control Setpoint Step Test - Results VacCanStepResponseTempAxis.pdf
Message ID: 2410     Entry time: Wed Sep 4 11:04:08 2019     In reply to: 2406     Reply to this: 2411
Author: anchal 
Type: DailyProgress 
Category: TempCtrl 
Subject: Vacuum Can Temperature Control Setpoint Step Test - Results 

Attached are the results of this step test.

  • The Vacuum Can Temperature PID reached the setpoint almost immediately.
  • The out-of-loop sensor has a different offset but shows same 1-degree change as an in-loop sensor.
  • In the FSS Slowout Voltages which control the NPRO Laser temperatures, we can see that South Slow PID goes to a steady-state more smoothly and without much oscillations.
  • While the North Slow PID shows some oscillations. I'm not sure what can be concluded from this observation.
  • Note that the cavity heater PID was switched off during these measurements but the heaters were left on to the values they were at before switching PID off.
  • The second attachment is an exponential decay fit of the slow voltage values after the two steps on each day on each path.
  • The values of these time constants vary from 3 hrs to 4 hrs depending on the day and path.
  • I was unable to convert the slow voltages to cavity temperature reliably. I found some estimates in CTN:2027 but they were not replied to positively. And the absolute value is still unknown, so this conversion would hardly give any new insight.
  • However, since temperature change would be some constant number only, it wouldn't affect the time constant estimate done here.

Code and Data

Attachment 1: VacCanStepResponse.pdf  425 kB  Uploaded Wed Sep 4 15:07:19 2019  | Hide | Hide all
VacCanStepResponse.pdf VacCanStepResponse.pdf VacCanStepResponse.pdf
Attachment 2: VacCanStepResponseFit.pdf  702 kB  Uploaded Wed Sep 4 15:07:37 2019  | Hide | Hide all
VacCanStepResponseFit.pdf VacCanStepResponseFit.pdf VacCanStepResponseFit.pdf VacCanStepResponseFit.pdf VacCanStepResponseFit.pdf VacCanStepResponseFit.pdf VacCanStepResponseFit.pdf VacCanStepResponseFit.pdf VacCanStepResponseFit.pdf VacCanStepResponseFit.pdf VacCanStepResponseFit.pdf VacCanStepResponseFit.pdf
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