bubba.gateley@LIGO.ORG - posted 17:09, Thursday 18 May 2017 - last comment - 20:41, Thursday 18 May 2017(36271)
End Station Temperatures
We have been working to stabilize the temperatures, mostly at End Y because that is the station that has the completed FMCS controls. End X should be completed by the end of this week. During this process several changes have been made to various components such as the face/by-pass damper, cooling valve, chillers etc. Currently the changes have only been made to the End Y station where we were trying to maintain 68 degrees F. After several conversations with Jeff K. and some calculations made by Jeff, he has determined that a more suitable temperature for E Y would be ~64 degrees F. I have changed the set point in the E Y VEA to to 64 F. I will monitor the temperature closely tonight and hopefully this will have the correct effect on the suspensions. I also had an alarm on the Mid X supply fan this morning and upon further investigation, I found that someone had turned the fan off at the electrical disconnect. I restored the HOA switch to auto position and started the fan.
J. Kissel, B. Gateley More on why I became convinced that the new FMCS temperature sensor array is reporting the wrong temperature (i.e. the set point creates a higher physical temperature than the FMCS error point reports). The message: I'm convinced that the FMCS sensor srray is incorrectly calibrated based on evidence from all other temperature sensors (direct or indirect) in the EY building (see below). Most convincingly is the PCAL Receiver Module's temperature sensor which is in the same units as the FMCS sensor and was reporting the same value prior to the upgrade (and was live throughout the upgrade). Using the difference between the FMCS sensor array and the PCAL receiver module, I recommended that Bubba adjust the FMC setpoint ~(22.4 - 20.2) [deg C] = (72.32 - 68.36) [deg F] = 4 [deg F] lower than it was -- hence he changed the set point from 68 to 64 [deg F]. %%%%%%%%%%%%% DETAILS %%%%%%%%%%%%% I've looked at as many direct and indirect temperature sensors as I know: Type Sub-System Channel Units Notes Temp Sensor FMCS H0:FMC-EY_VEA_AVTEMP_DEG[C/F] [Celsius / Fahrenheit] Average of FMCS sensors below; error point for FMCS temp control servo H0:FMC-EY_VEA_202A_DEG_[C/F] [Celsius / Fahrenheit] H0:FMC-EY_VEA_202B_DEG_[C/F] [Celsius / Fahrenheit] H0:FMC-EY_VEA_202C_DEG_[C/F] [Celsius / Fahrenheit] H0:FMC-EY_VEA_202D_DEG_[C/F] [Celsius / Fahrenheit] Temp Sensor PCAL H1:CAL-PCALY_TRANSMITTERMODULETEMPERATURE [Celsius] reports a few [deg C] higher temp because of the 2W laser inside H1:CAL-PCALY_RECEIVERMODULETEMPERATURE [Celsius] Temp Sensor CCG H1:PEM-EY_TEMP_VEA1_DUSTMON_DEGF [Fahrenheit] Temp Sensor PEM H1:PEM-Y_EBAY_RACK1_TEMPERATURE [Celsius] Heavily influenced by rack temperature, but shows gross trend Temp Sensor PEM H1:PEM-EY_TEMPERATURE_BSC10_ETMY_MON Uncalibrated!! Attached to BSC10 (ETMY's chamber) Temp Sensor SEI H1:ISI-GND_BRS_ETMY_TEMPR Uncalibrated!! Inside the heavily insulated BRS enclosure Disp. Sensor SUS H1:SUS-ETMY_M0_DAMP_V_IN1_DQ [um] -106 [um/(deg C)] LHO aLOG 15995 H1:SUS-ETMY_R0_DAMP_V_IN1_DQ [um] [um/(deg C)] is probably roughly the same as M0 H1:SUS-TMSY_M1_DAMP_V_IN1_DQ [um] -88 [um/(deg C)] LHO aLOG 15995 Disp. Sensor SUS H1:SUS-ETMY_M0_DAMP_P_IN1_DQ [urad] -270 [urad/(deg C)] LHO aLOG 15888 H1:SUS-ETMY_R0_DAMP_P_IN1_DQ [urad] [urad/(deg C)] is probably roughly the same H1:SUS-ETMY_L1_WIT_P_DQ [urad] [urad/(deg C)] is probably less H1:SUS-ETMY_L2_WIT_P_DQ [urad] [urad/(deg C)] is probably even less (because it's -96 urad/(deg C) at the test mass) H1:SUS-ETMY_L3_OPLEV_PIT_IN1_DQ [urad] shows pitch of ETM, but also sensitive to temperature itself H1:SUS-TMSY_M1_DAMP_P_IN1_DQ [urad] [urad/(deg C)] hasn't be I attach 3 sets of 10 day trends. - The first is the most convincing, showing the FMCS temperature against the PCAL temeperature sensors. This, again, is what I used to calibrate to what Bubba should change the FMCS cooling system's set point. - The second shows that how the vertical displacement of the suspensions evolved in the same manor as the PCAL sensors throughout. Unfortunately, there seems to be about a factor of two difference between the VEA temperature change and the retro-predicted change based on the [um/(deg C)] of both the QUAD and the TMTS. Not worth chasing the discrepancy. - The third attachment shows some of the rest of the temperature sensors and temperature sensitive instrumentation, and although they're all differently calibrated and/or uncalibrated, they still show the same consistent trend of a ~2 [deg C] increase all over the VEA and even in the electronics rack. Finally, I attach a rough layout of all of the above sensors.I've created a dataviewer template with the above channels pre-selected for future ease of trending. It now lives under version control here: /opt/rtcds/userapps/release/pem/h1/dvtemplates/EYVEA_Temperature_Trends.xml I attach the initial version, in case you don't want to remember where it lives.