Reports until 14:51, Tuesday 14 July 2026
H1 SUS (SQZ, SUS)
rahul.kumar@LIGO.ORG - posted 14:51, Tuesday 14 July 2026 - last comment - 15:00, Tuesday 14 July 2026(91027)
HAM7 status update - ZM5 (PSAMS) replaced, re-installed in chamber and is fully functional now.

R Crouch, R Kumar

SUS ZM5 has been re-installed in HAM7 chamber after replacing the faulty bottom mass PSAMS unit with a spare one sent by CIT. 

The bottom wires were replaced and the entire was chain was re-balanced after suspending all stages. The PSAMS cable (with mighty mouse connector) was carefully laced around the cage and clamped at strategic position (so that it doesn't short with the cage). We then took a health check and the suspension looks healthy - see transfer function results in attachment01 and attachement02 (we see some slight shift in frequencies, especially P dof - however they can be easily damped with the current filters we have in place).

Attached below are many pictures showing ZM5 in chamber after the repair work was complete and suspension re-installed.

We also took pictures for reference after installing the wires and balancing it after suspending all stages - outside the chamber on the table.

Details of our repair work are listed in this checklist attached below.

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rahul.kumar@LIGO.ORG - 15:00, Tuesday 14 July 2026 (91029)SQZ, SUS

We re-tested  (see picture01 and picture02) the strain gauge readout for the PSAMS units after installing it in ZM5 and then placing it in HAM7 chamber, connected to the electronics chain of ZM5. Given below are the test results,

Voltage Calibrator Setting (Voltage)  PZT (Voltage) Strain Gauge (Voltage)
+10 0.384 2.780
+9 103.5 2.966
+8 20.33 3.179
+7 30.30 3.408
+6 40.28 3.658
+5 50.25 3.910
+4 60.23 4.177
+3 70.2 4.453
+2 80.1 4.744
+1 90.1 5.090
0 100.1 5.350
-1 110.1 5.660
-2 120.0 5.965
-3 130.0 6.275
-4 140.0 6.591
-5 150 6.900
-6 159.9 7.210
-7 169.8 7.530
-8 179.8 7.850
-9 189.8 8.170
-10 194.0 8.320