Today, we resumed testing on ISI-BSC6. After turning the coil drivers back on, we performed basic tests to quickly check the health of the ISI. (SUS-ISI watchdogs interactions, drive all actuators during few seconds, take spectra of all sensors).

Note: When we manually (gently) pushed the table to replug a cable, both ISI and SUS watchdogs immediately tripped but the CDS master watchdog didn't. However, indicators showed that it was closed from tripping. The CDS watchdogs thresholds seem appropriate.

Few tests were performed in the afternoon:

- Offset CPS table unlocked
- Static test in the local basis
- Spectra of all sensors
- Range of motion
- Linearity Test (SUS watchdogs tripped, why?)
- Check the pressure sensors
- Complete the transfer functions measurements (the 700mHz - 10Hz section). Other sections were measured on February 30.

It looks good. See attachment and links below.

Offsets CPS:
https://svn.ligo.caltech.edu/svn/seismic/BSC-ISI/H2/ETMY/Data/Static_Tests/
LHO_ISI_BSC6_CPS_Read_Back_ISI_Unlocked_2012_03_29_113603.mat

Range of motion:
https://svn.ligo.caltech.edu/svn/seismic/BSC-ISI/H2/ETMY/Data/Static_Tests/
LHO_ISI_BSC6_Range_Of_Motion_20120329.mat

Pressure sensors:
https://svn.ligo.caltech.edu/svn/seismic/BSC-ISI/H2/ETMY/Data/Static_Tests/
LHO_ISI_BSC6_Pressure_Sensors_Check_Calibrated_2012_03_29_115020.mat

Spectra:
https://svn.ligo.caltech.edu/svn/seismic/BSC-ISI/H2/ETMY/Data/Figures/Spectra/Undamped/
LHO_ISI_BSC6_ASD_m_LOC_CPS_T240_L4C_GS13_2012_03_29_113004.fig

Transfer functions can be found at:
https://svn.ligo.caltech.edu/svn/seismic/BSC-ISI/H2/ETMY/Data/Figures/Transfer_Functions/Measurements/Undamped/

• LHO_ISI_BSC6_TF_L2L_Raw_from_ST1_ACT_to_ST1_CPS_2012_03_29.fig
• LHO_ISI_BSC6_TF_L2L_Raw_from_ST1_ACT_to_ST1_L4C_2012_03_29.fig
• LHO_ISI_BSC6_TF_L2L_Raw_from_ST1_ACT_to_ST1_T240_2012_03_29.fig
• LHO_ISI_BSC6_TF_L2L_Raw_from_ST2_ACT_to_ST2_CPS_2012_03_29.fig
• LHO_ISI_BSC6_TF_L2L_Raw_from_ST2_ACT_to_ST2_GS13_2012_03_29.fig

Comparisons with transfer functions measured in the staging building can be found at:
https://svn.ligo.caltech.edu/svn/seismic/BSC-ISI/H2/ETMY/Data/Figures/Transfer_Functions/Comparisons/L2L/

• LHO_ISI_BSC6_Comparison_TF_L2L_ST1_ACT_H_to_ST1_CPS_H_20111025_vs_20120329.fig
• LHO_ISI_BSC6_Comparison_TF_L2L_ST1_ACT_H_to_ST1_L4C_H_20111025_vs_20120329.fig
• LHO_ISI_BSC6_Comparison_TF_L2L_ST1_ACT_V_to_ST1_CPS_V_20111025_vs_20120329.fig
• LHO_ISI_BSC6_Comparison_TF_L2L_ST1_ACT_V_to_ST1_L4C_V_20111025_vs_20120329.fig
• LHO_ISI_BSC6_Comparison_TF_L2L_ST2_ACT_H_to_ST2_CPS_H_20111025_vs_20120329.fig
• LHO_ISI_BSC6_Comparison_TF_L2L_ST2_ACT_H_to_ST2_GS13_H_20111025_vs_20120329.fig
• LHO_ISI_BSC6_Comparison_TF_L2L_ST2_ACT_V_to_ST2_CPS_V_20111025_vs_20120329.fig
• LHO_ISI_BSC6_Comparison_TF_L2L_ST2_ACT_V_to_ST2_GS13_V_20111025_vs_20120329.fi

Main differences are:

- The DC gains (cables resistance)
- Resonances of the rigid body modes [1; 10]Hz (different payload)
- ST1-CPS resonances different in the staging building and EY (Teststand short legs vs long legs). Resonance at 53Hz on ST1 CPS V1.
- Resonance at 78.5Hz on stage 2 sensors (Payload)
- Similar at high frequencies