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Entry  Tue Aug 31 18:20:42 2010, tara, Notes, RefCav, change acav setpt 
    Reply  Tue Aug 31 18:33:13 2010, Frank, Notes, RefCav, changed acav setpt back to 37.3 
       Reply  Tue Aug 31 21:37:11 2010, Frank, Notes, RefCav, changed acav setpt back to 37.3 
Message ID: 333     Entry time: Tue Aug 31 18:33:13 2010     In reply to: 332     Reply to this: 334
Author: Frank 
Type: Notes 
Category: RefCav 
Subject: changed acav setpt back to 37.3 

don't change anything until it is stable and you thought about it carefully. The system was totally out of control, check the dataviewer!.
So there is no way to make an estimate for the values as you have no equilibrium!! That takes several hours after ANY change to the system, like rebooting the crate or turning on a temp control loop.
Remember: time constants are several hours!

So be patient and wait until tomorrow or late tonight before you make estimates and changes. Both temperatures are NOT close to their original setpoint and largely fluctuating.
RCAV is at 34.8 instead of 35 and ACAV changed from 37.1 to 37.45 within the last hours.
So no way to make the right adjustments right now, as your laser SLOWDC value does not reflect the actual temperature of the chamber.

Changed it back to the original settings (37.3) as those were working over several days before the system stopped working properly...

Quote:

I adjust SLOWDC to see what value to lock each cavity.

For ACAV I adjust SLOWDC so that VCOMON fluctuates around 0 and record the value of SLOWDC

I adjust ACAV_SETPT to see how the DC changes (in RED), it seems I have to reduce the ACAV_SETPT

                             ACAV                              RCAV

SLOWDC       -0.1118 ->-0.1151             -0.1051

SETPT           37.3      -> 37.35                       35

 

Now, ACAV_SETPT is changed to 37.15, but ACAV_TEMPAVG goes up (after 30mins.) to ~37.43 (from 37.3).

The variance from ACAV's 4 temp sensors are getting larger.

 

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