40m QIL Cryo_Lab CTN SUS_Lab TCS_Lab OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
  40m Log  Not logged in ELOG logo
Entry  Fri Jan 5 19:19:25 2018, rana, Configuration, SEI, Barry Controls 'air puck' instead of 'VOPO style' breadboard mm_slm.jpgScreen_Shot_2018-01-05_at_7.25.47_PM.png
    Reply  Wed Jan 10 16:27:02 2018, Steve, Configuration, SEI, load cell for weight measurement stacis3LoadCells.png
       Reply  Wed May 2 10:03:58 2018, Steve, HowTo, SEI, preparation of load cell measurement at ETMX 6x
          Reply  Thu May 3 09:56:42 2018, Steve, HowTo, SEI, preparation of load cell measurement at ETMX 
             Reply  Mon May 14 08:55:40 2018, Dennis Coyne, HowTo, SEI, preparation of load cell measurement at ETMX 
    Reply  Tue Jan 23 16:02:05 2018, Steve, Configuration, SEI, load cells stacis3LoadCells.pngDSC00025.JPGDSC00026.JPG
Message ID: 13526     Entry time: Wed Jan 10 16:27:02 2018     In reply to: 13505     Reply to this: 13806
Author: Steve 
Type: Configuration 
Category: SEI 
Subject: load cell for weight measurement 

We could use similar load cells   to make the actual weight measurement on the Stacis legs. This seems practical in our case.

I have had bad experience with pneumatic Barry isolators.

Our approximate max compression loads are 1500 lbs on 2 feet and 2500 lbs on the 3rd one.

Quote:

We've been thinking about putting in a blade spring / wire based aluminum breadboard on top of the ETM & ITM stacks to get an extra factor of 10 in seismic attenuation.

Today Koji and I wondered about whether we could instead put something on the outside of the chambers. We have frozen the STACIS system because it produces a lot of excess noise below 1 Hz while isolating in the 5-50 Hz band.

But there is a small gap between the STACIS and the blue crossbeams that attache to the beams that go into the vacuum to support the stack. One possibility is to put in a small compliant piece in there to gives us some isolation in the 10-30 Hz band where we are using up a lot of the control range. The SLM series mounts from Barry Controls seems to do the trick. Depending on the load, we can get a 3-4 Hz resonant frequency.

Steve, can you please figure out how to measure what the vertical load is on each of the STACIS?

 

Attachment 1: stacis3LoadCells.png  1.313 MB  Uploaded Thu Jan 11 08:32:49 2018  | Hide | Hide all
stacis3LoadCells.png
ELOG V3.1.3-