Differences between revisions 24 and 41 (spanning 17 versions)

KAGRA VIS Operations Manual - LVDT

LVDTs are used for vertical sensing and actuation in all the GAS filters and for horizontal sensing and actuation in all the IP stages.

See LVDT Signal Conditioning for useful background on LVDT demodulation.

See JGW-T1201255 for description of the Nikhef-supplied cards, and JGW-T1604798 for more information on how to tune the demodulation circuit.

LVDT Calibration Procedure: JGW-E1707287 or LVDT Calibration Procedure.

LVDT Coil and Driver Data

Type A	Test Mass Suspensions
Type B	BS and SR suspensions
BS Data
SR2 Data
SR3 Data
SRM Data
Type Bp	PR Suspensions
Type C	Modecleaner Suspensions

Yoke Height Settings

The yoke should be set so that the double and single LVDT coils are symmetrically aligned when the keystone is at nominal height. It is convenient to set this in terms of the amount the PEEK coil former sticks out above the filter baseplate.

Bottom Filter (BS and SRx)

Note that the CAD is wrong for the bottom filter yoke:

Standard Filter (BS and SRx)

Top Filter (BS and SRx)

Summary

GAS Filter	Yoke Height	Keystone Height
BS BF	3.5 mm	65.5 mm (up from baseplate)
SR BF	3.5 mm	65.5 mm (up from baseplate)
BS SF	6 mm	65.5 mm (up from baseplate)
SR SF	6 mm	65.5 mm (up from baseplate)
BS F0	36 mm	153 mm (up from top plate), 16.5 mm (down from ring)
SR F0	34 mm	151 mm (up from top plate), 16.5 mm (down from ring)

Type Bp Data

Your data here!

Stocktake

Old: LVDT Stocktake as of 2018-04-13

KAGRA/Subgroups/VIS/OpsManual/LVDT (last edited 2018-09-14 17:27:24 by YoichiAso)

-  ⇤ ← Revision 24 as of 2018-04-11 15:47:03 → 
  Size: 4116
  Editor: EnzoTapia
  Comment:
+   ← Revision 41 as of 2018-09-14 16:37:53 → ⇥
  Size: 2666
  Editor: YoichiAso
  Comment:
-Deletions are marked like this.
+Additions are marked like this.
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-Summary of LVDTs Calibration Procedure(JGW-E1707287). Here: [[attachment:LVDT_Calibration.pdf| LVDT Calibration Procedure]].
+LVDT Calibration Procedure: [[https://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=7287|JGW-E1707287]] or [[attachment:LVDT_Calibration.pdf| LVDT Calibration Procedure]].
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-== Type A ==
Your data here!

== Type B Data ==
=== LVDT Drivers Data ===

For SR2:

||LVDT Driver S.N. ||Left card ||Stage ||Resistor value [ohm] ||Reference Signal || Gain  ||Right card ||Stage ||Resistor value [ohm] ||Reference Signal || Gain  ||
||<|4> SR2: SN 7777777 ||R0 ||BF GAS ||59.2 ||4. Vpp || 4./5.02 = 0. ||R0 ||PI LVDT#1 ||50.1 || 4. Vpp || 4./5.02 = 0. ||
||R1 ||SF GAS ||36.3 ||4. Vpp || 4./5.02 = 0. ||R1 ||PI LVDT#2 ||50.6 ||4. Vpp || 4./5.02 = 0. ||
||R2 ||F0 GAS ||59.6 ||4. Vpp || 4./5.02 = 0. ||R2 ||PI LVDT#3 ||51.2 ||4. Vpp || 4./5.02 = 0. ||
||R3 ||Not used ||59.5 ||4. Vpp || 4./5.02 = 0. ||R3 ||Not used ||50.0 ||4. Vpp || 4./5.02 = 0. ||

For SR3:

||LVDT Driver S.N. ||Left card ||Stage ||Resistor value [ohm] ||Reference Signal || Gain  ||Right card ||Stage ||Resistor value [ohm] ||Reference Signal || Gain  ||
||<|4> SR3: SN 1807783 ||R0 ||BF GAS ||60.0 ||4.90 Vpp || 4.90/5.02 = 0.976 ||R0 ||PI LVDT#1 ||50.7 || 4.90Vpp || 4.90/5.02 = 0.976 ||
||R1 ||SF GAS ||60.7 ||4.86 Vpp || 4.86/5.02 = 0.968 ||R1 ||PI LVDT#2 ||50.7 ||4.88 Vpp || 4.88/5.02 = 0.972 ||
||R2 ||F0 GAS ||60.9 ||4.86 Vpp || 4.86/5.02 = 0.968 ||R2 ||PI LVDT#3 ||50.0 ||4.88 Vpp || 4.88/5.02 = 0.972 ||
||R3 ||Not used ||60.7 ||4.86 Vpp || 4.86/5.02 = 0.968 ||R3 ||Not used ||50.9 ||4.86 Vpp || 4.86/5.02 = 0.968 ||

For SRM:

||LVDT Driver S.N. ||Left card ||Stage ||Resistor value [ohm] ||Reference Signal || Gain  ||Right card ||Stage ||Resistor value [ohm] ||Reference Signal || Gain  ||
||<|4> SRM: SN 1807786 ||R0 ||BF GAS ||60.6 ||5.04 Vpp || 5.04/5.04 = 1.0 ||R0 ||PI LVDT#1 ||50.0 || 5.0 Vpp || 5.0/5.04 = 0.992 ||
||R1 ||SF GAS ||60.1 ||4.96 Vpp || 4.96/5.04 = 0.984 ||R1 ||PI LVDT#2 ||50.0 ||4.92 Vpp || 4.92/5.04 = 0.976 ||
||R2 ||F0 GAS ||60.7 ||4.96 Vpp || 4.96/5.04 = 0.984 ||R2 ||PI LVDT#3 ||50.5 ||4. Vpp || 5.0/5.04 = 0.992 ||
||R3 ||Not used ||61.2 ||4.94 Vpp || 4.94/5.04 = 0.98 ||R3 ||Not used ||50.8 ||4. Vpp || 4.9/5.04 = 0.972 ||

New box for SRM. Adjusting the potentiometers to have the same values:

||LVDT Driver S.N. ||Left card ||Stage ||Resistor value [ohm] ||Reference Signal || Gain  ||Right card ||Stage ||Resistor value [ohm] ||Reference Signal || Gain  ||
||<|4> SRM: SN 1403020 ||R0 ||BF GAS ||60.2 || - Vpp || - = - ||R0 ||PI LVDT#1 ||50.4 || - Vpp || - = - ||
||R1 ||SF GAS ||60.1 || - Vpp || - = - ||R1 ||PI LVDT#2 ||50.3 ||- Vpp || - = - ||
||R2 ||F0 GAS ||60.7 || - Vpp || - = - ||R2 ||PI LVDT#3 ||50.3 ||- Vpp || - = - ||
||R3 ||Not used ||61.0 || - Vpp || - = - ||R3 ||Not used ||50.2 ||- Vpp || - = - ||
+== LVDT Coil and Driver Data ==
||[[KAGRA/Subgroups/VIS/OpsManual/TypeA|Type A]]||Test Mass Suspensions||
||[[KAGRA/Subgroups/VIS/OpsManual/TypeB|Type B]]||BS and SR suspensions ||
||||[[KAGRA/Subgroups/VIS/OpsManual/TypeB/BSData#lvdt|BS Data]]||
||||[[KAGRA/Subgroups/VIS/OpsManual/TypeB/SR2Data#lvdt |SR2 Data]]||
||||[[KAGRA/Subgroups/VIS/OpsManual/TypeB/SR3Data#lvdt |SR3 Data]]||
||||[[KAGRA/Subgroups/VIS/OpsManual/TypeB/SRMData#lvdt |SRM Data]]||
||[[KAGRA/Subgroups/VIS/OpsManual/TypeBp|Type Bp]]||PR Suspensions||
||[[KAGRA/Subgroups/VIS/OpsManual/TypeC|Type C]]||Modecleaner Suspensions||
-Line 64:
+Line 34:
+=== Top Filter (BS and SRx) ===

{{attachment:YokeHeightExampleBSF0.png| |width=400}}{{attachment:YokeHeightExampleSRF0.png| |width=400}}
-Line 67:
+Line 41:
-||BS BF||3.5 mm||65.5 mm||
||SR BF||3.5 mm||65.5 mm||
||BS SF||6 mm||65.5 mm||
||SR SF||6 mm||65.5 mm||
+||BS BF||3.5 mm||65.5 mm (up from baseplate)||
||SR BF||3.5 mm||65.5 mm (up from baseplate)||
||BS SF||6 mm||65.5 mm (up from baseplate)||
||SR SF||6 mm||65.5 mm (up from baseplate)||
||BS F0||36 mm||153 mm (up from top plate), 16.5 mm (down from ring)||
||SR F0||34 mm||151 mm (up from top plate), 16.5 mm (down from ring)||
-Line 74:
+Line 50:
+<<Anchor(stocktake)>>
= Stocktake =

[[LVDT20180413|Old: LVDT Stocktake as of 2018-04-13]]