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Reports until 01:05, Tuesday 06 December 2016
H1 TCS
thomas.shaffer@LIGO.ORG - posted 01:05, Tuesday 06 December 2016 - last comment - 09:30, Wednesday 07 December 2016(32230)
TCSY Chiller flow issue

The TCSY chiller flow seems to be struggling for the last 40min or so. This doesn't seem to be the normal issue of an air bubble because it is not recovering as it normally would. I saw a WP for the replacement of this flow meter but I didn't see an alog stating that it happened.

Attached is an hour trend of the flow rate.

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Comments related to this report
thomas.shaffer@LIGO.ORG - 02:01, Tuesday 06 December 2016 (32231)

Seems to have stablized itself now, back at 3.0Gpm

betsy.weaver@LIGO.ORG - 21:07, Tuesday 06 December 2016 (32288)

Eh, this actually is kinda the usual "thing" going on with this sensor of late...  It drops low for a while ~30-60 mins and then recovers eventually.  The work permit we have open is to fix next Tuesday.

aidan.brooks@LIGO.ORG - 09:30, Wednesday 07 December 2016 (32304)

I was wondering if this was coming from the CO2 controller chassis, D1200745. I had a look to see if there were accompanying glitches on the CO2Y laser temperature channel which might indicate a common cause. Whilst there are some glitches that show up simultaneously on both channels, there are many that are not simultaneous. It is far from obvious that there is a common cause for the flow rate variations.

 

% check to see if the CO2Y laser flow meter is broken or if there is a

% problem with electronics instead. Compare to CO2Y laser temperature

 

t0 = 1165166030 - 72*3600;

t1 = t0 + 2*24*3600;

 

chan = {'H1:TCS-ITMY_CO2_LASERTEMPERATURE.mean,m-trend', ...

    'H1:TCS-ITMY_CO2_FLOWRATE.mean,m-trend'};

 

[data, t, info] = get_data(t0,t1,chan,[]);

 

subplot(2,1,1)

plot((1:size(data,1))/60, data(:, 1)); grid on

axis([0 48 23.72 23.82])

xlabel('Time (hr)')

ylabel('CO2Y laser temperature (C)')

title('CO2Y laser channel glitches - correlated or not?')

 

subplot(2,1,2)

plot((1:size(data,1))/60, data(:, 2)); grid on

axis([0 48 2 3.5])

xlabel('Time (hr)')

ylabel('CO2Y flow rate (gpm)')

orient tall

print('-dpdf', 'CO2Y_flow_rate_errors.pdf')

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