If anybody wants a fancy single-axis seismometer for a while (GS-13), then please let me know.

Air conditioning maintenance is scheduled for tomorrow morning till noon.

 I have finally plugged GUR1 back in....it is down at ETMY for now, since that's where the cable was.  BLRMS are back up on the projector.

Jeff is still working on the filter banks.

The attached plots display RMS noise from various accelerometers and seismometers over the past 90 days. One can see how after the reinstallation of the seismometers in November, RMS from the GUR1Z and GUR1X channels decreases by a factor of about 100 from data in August. Additionally, the RMS over the course of the last 90 days has notably decreased in all instruments. In many cases, the RMS is only the result of inherent electronics noise, rather than from a signal.

[Den, Ayaka]

We found that seismometer was working and the calibration in the filter banks should have been wrong.
We turned off the all FM2 filter in RMS filter banks.

We also installed STS seismometer. It is under the BS. Now we have spectrum of three seismometers.

RA: the above plot is kind of unreadable and useless. Please replace with something legible and put in some words about why there is a wrong filter, what exactly it is, etc., etc. etc. And why would you leave in a filter which is not supposed to be on? We might as well leave a few secretly broken chairs in the control room...

 First of all, STS-2 is in the end of X arm, GUR2 is under BS, GUR1 is in the end of Y arm.

BLRMS were small because we applied calibration from counts to um/s two times. In the past we had calibration in the RMS BP filter bank (vel2vel = FM2). Now we have calibration in the seismometer input filter bank so we can save calibrated _OUT channels.

 BT EM172 microphones  are ordered.

CALIFORNIA INSTITUTE OF TECHNOLOGY

                 FACILITIES MANAGEMENT

**PLEASE POST**

Building:         Campus

Date:             Thursday October 04,2012

This morning at 2:17 a.m. much of the City of Pasadena including our Campus experienced a electric power sag of short duration, approximately 1/10 of a second. The cause was a fault on one of Pasadena’s 17KV circuits. Some sensitive equipment have been impacted.

Contact:          Mike Anchondo x-4999

How NOT to:

The janitor can not clean in areas like this. He may only steps on these cables accidentally as he dust wiping our chambers.

 Sorry for the mess. I fixed it.

 Looking at the PEM BLRMS, I noticed that the GUR1Z channel had a much reduced microseism compared to the GUR1X. Looking at the BLRMS screens everything seems ON, although its a mess (too many filters in the banks, etc. - clean this up, PEM people).

 Looking at the Z channel in DTT, I see that the Z spectra looks double high pass filtered below ~1 Hz.     Needs some attention in the daytime.

From Den and Ayaka's elog entry from Nov 29, its clear that this problem is there at that time. It seems that the seismometer was not even hooked up before then. Perhaps Tara returned the seismometer around Thanksgiving and then someone here hooked it up but neglected to log this work? If so, please make an elog now describing the installation of this sensor at the 40m and log any future work which takes place at the 40m lab even if you think it is inconsequential.

 Yesterday I wanted to recenter Guralps. I turned them off, understood that would be able to center them because we do not have power cable to Guralp box from Tara yet and turned them back on.

I've switched Guralp cables and spectrums are fine now.

 SRM, ITMY and MC3 moved some what, but how are the TT? It may worth looking at them before we vent.

I have updated the Seismic Striptool display which is plotted on the wall in the control room. Please take a look and make comments. We should finalize it and not change it anymore.

By having an unchanging display, we can get used to small changes in the seismic environment which disrupt our locking.

1. y-scale is now linear; the log-scale was suppressing the factor of 2-3 variations which are important to us.
2. Just as the rainbow does, the colors now go from red to purple to represent the noise from 0.1 - 30 Hz: the red traces are 0.1-0.3 Hz, the green/yellow traces are 0.3-3 Hz, and the blue/purple traces are 3-30 Hz.
3. This is just showing GUR1. Let's try to keep this seismometer working so that we can have some long term record of the seismicity here. This means don't click off the buttons, disconnect the sensor, reboot the machine, etc. When you do do these things, elog them.

Please wipe, clean car wheels and wear booties entering the 40m lab.

Obviously this person has no idea about our clean room rules.

The wood exteier walls, gutters and doors were painted at CES-Annex building #69

The BLRMS have been bad again, since the computer crash of last week.  Finally getting around to looking into it, I discovered that there are filter banks that have the microns/sec calibration filters, which are not accessible from the sitemap.  I have added links to them for GUR1 and GUR2.  We need to make the PEM/BLRMS screens macro-expansion-y, so that I don't have to change each screen individually.

Anyhow, the BLRMS are back.

 The east and south end of the 40m emergency exit doors are sealed- tapped off temporarily.  They will be painted on the out side only.  This job will be done by tomorrow noon

 Do not open chamber if you smell the paint !

 The bad outside air quality is pushing up the inside counts.

The outside air is 5 million counts / cf min for 0.3 micron and 2 million counts / cf min for 0.5 micron particles

Do not open chamber over 10,000 counts / cf min of 0.5 micron

 The east and south end of the 40m emergency exit doors received new safety signs.

Manasa and I have been wondering why the low frequency seismic noise has been different in the last few days/weeks.  I went over to visit the Rock Monster, a.k.a. the Earth Surface Dynamics Laboratory next door, and the grad student turned it up for me (increased water flow significantly) for a few minutes.  Then I came back to look at the BLRMS, and you can see the low frequency increase a few minutes ago, when he turned it up on high.  He said that they run it on low almost all the time, 9am-5pm ish, and on high for an hour or so at a time periodically during the day.

 The air cond is out of order at the area covered by racks 1 X 1  through 1 X 7

The arm X and Y AC units are working.

Granite base 20" x 20" x 5"  locations are on the CES side of our IFO arms:  as shown ETMY_ south-west, ETMX_north-east, ITMX_south-east . No height limitation. This side of the tube has no traffic.

SS cover McMaster#  41815T4  (H) SS container cov

This is my interpretation of where Steve is proposing to place the seismometers (he wrote ITMX southwest, but I'm pretty sure from the photo he means southeast).

I think his point is that these locations are on the less-used side of the beam tube, so they will not be in the way.  Also, they are not underneath the tube, so we will not have any problems putting the covers on/taking them off.

 Outside air quality at 8:30am  1.1 million of 0.5 micron particles cf / min with MET counter #2

AC unit output measured  directly at the outlet of east end  6,000  and south end 3,000 of 0.5 micron particles cf / min with counter #2

Lab measurement at the top of IOOC 20K of 0.5 micron particles cf / min with MET #1

HEPA filters: 2 mobile units  at the middle of the east arm at speed 100%, PSL enclosure 20% and south end flow bench are running.

The PSL, south flow bench and mobile unit (Envirco  sn69406003 ) measured zero counts of 0.5 & 0.3 micron particles

Envirco HEPA filter unit sn 69406001 measured 50 particles of 0.5micron and 320 of 0.3 micron particles cf / min with counter #2

This filter will be replaced.

NOTE: inside air quality peaks we can not control. It depends on the weather and our house keeping.

When your work is particle sensitive keep your eyes on the particle counter.

 We got granite bases today from the manufacturer. We plan to set them up on Wednesday, 8 am. Please note, there will be an installation mess at Xend, Yend and corner during ~4 hours. Let us know if you have any objections to do this at this particular time.

Installation locations are specified in elog 8270, scheme attached is valid except for Xend. Instrument will be installed on the place of nitrogen containers.

(  next to the wall at corner sout-east of the south end )

 The carpenter shop finished the installation of the 3 granite bases.Rapid Set Cement All high strength non-shrink grout was used.

 Compressive strength  3000 PSI at 1 hour and 9000 PSI at day 28 The janitor is still cleaning up after them at the south end.

The  soft silicon gas kits are working well with the SS can.  Den is making  the adaptor plate drawing for the feedthrough.

I moved the two Trillium seismometers that Den left on the electronics bench out onto the new concrete blocks in the lab that will be their final resting places.  I moved one onto the slab at the vertex and the other to the slab at the Y end.  I left them both locked and just sitting on the concrete.

The pile of readout electronics that were sitting next to them I moved on to the yellow foam box half way down the MC tube, between the MC tube and the X arm tube.  This is obviously not a good place to store them, but I couldn't think of a better place to put them for the moment.

 To put everything in one place I add a final drawing of the base to this elog.

 Next time we continue with wiring and putting temperature and pressure sensors inside the box. Connector support plate drawing is attached. We'll have sensors inside the kit with STS-2 or Trillium as their connector is small enough (19 pin vs 26 pin for Guralps) that we can put an additional 4 pin lemo connecor (2 pins for each sensor). I think EGG.0B.304.CLL is good for this application. Temperature and pressure sensor we can by from omega.

Something that I want to look at is the coherence between seismic motion and PRM motion.  Since Den has been working on the fancy new seismometer installations, I got caught up for the day with getting the new corner seismometer station set up with a T240.  Later, Rana pointed out that we already have a Guralp sitting underneath the POX table, and that will give us a good first look at the coherence.  However, I'm still going to write down all the cable thoughts that I had today:

The cables that came with the electronics that we have (from Vladimir and tilt meter -land) are not long enough to go from the seismometer to 1X7, which is where I'd like to put the readout box (since the acquisition electronics are in that rack). I want to make a long cable that is 19pin MilSpec on one end, and 25pin Dsub on the other.  This will eliminate the creative connector type changes that happen in the existing setup.  However, before making the cable, I had to figure out what pins go to what.  So.

25pin Dsub          19pin MilSpec

1                   P

2                   N

3                   E

4                   No conn

5                   D

6                   R and V

7                   H

8                   J

9                   No connection

10                  T

11                  F

12                  L

13                  No conn

14                  B

15                  A

16                  R and V

17                  No conn

18                  C

19                  G

20                  G

21                  K

22                  U

23                  No conn

24                  S

25                  M 

I am not sure why R and V are shorted to each other, but this connection is happening on the little PCB MilSpec->ribbon changer, right at the MilSpec side.  I need to glance at the manual to see if these are both ground (or something similar), or if these pins should be separate. Also, I'm not sure why 19 and 20 are shorted together.  I can't find (yet) where the short is happening. This is also something that I want to check before making the cable.

Den had one Female 19 pin MilSpec connector, meant for connecting to a T240, but the cable strain relief pieces of the connector have 'walked off'.  I can't find them, and after a solid search of the control room, the electronics bench, and the place inside where all of Den's connectors were stored, I gave up and ordered 2 more.  If we do find the missing bits for this connector, we can use it for the 2nd T240 setup, since we'll need 2 of these per seismometer. If anyone sees mysterious camo-green metal pieces that could go with a MilSpec connector, please let me know.

[Evan, Jenne]

Evan brought the Guralp handheld readout paddle and cables back from the ATF (Zach is using GUR2 and one of the T240s for gyro stuff this week), and we recentered the GUR1 masses.  N/S and Vert were okay (within 0.1 V), but E/W was at -0.5 V, so we set it at zero.  We then plugged the Guralp back in, and turned on the readout box.

There isn't much of a change on the BLRMS on the wall, so it's possible that we weren't actually having any trouble anyway. 

For quite a while (no one knows how long), we've seen fluctuations in the 10-30 Hz seismic motion. This shows up as the purple trace on the seismic BLRMS on the wall projector.

The second plot shows that this is not only a periodic increase in the usual 29.5 Hz HVAC peak, but also an anomolous 32.2 Hz peak. Probably some malfunctioning machinery - maybe in the 40m or maybe on the roof.

The BLRMS are totally crazy today!  I'm not sure what the story is, since it's been this way all day (so it's not an earthquake, because things eventually settle down after EQs).  It doesn't seem like anything is up with the seismometer, since the regular raw seismic time series and spectrum don't look particularly different from normal.  I'm not sure what's going on, but it's only in the mid-frequency BLRMS (30mHz to 1Hz).

Here are some 2 day plots:

 Particle counts were measured inside the PSL enclosure at 40VAC variac setting.

Directly under HEPAs, on the east half of the optical table : 0.3 micron    20  particles / cu ft,       0.5 micron     0  p / cu ft,      0.7 micron        0 p / cu /ft

Away from the HEPAs, on the west edge of the op table:     0.3 micron   960  particles / cu ft,      0.5 micron    50 p / cu ft,       0.7 micron      20 p / cu ft

We may want to increase the RPM a little bit.

Checked our counters against recently calibrated Met One GT-526:

#1 is right on, #2 measured 25% less (it will go for calibration)

Flow bench at the south end :   zero particle for all 3 sizes

IOO chamber particle logging  measures  0.5 and 1 micron.  Chamber opening limit is set to 10,000 particles max of 0.5 micron

At 10,000 p of 0.5 micron means ~100,000 - 180,000 p of 0.3 micron

We may have to lower the limit.

Its an increase in the microseismic peak. Don't know what its due to though.

Keven and Steve,

The 3 cranes tested and  wiped off as preparation for upcoming vent.

 Once you install a matlab newer than 2012a, you can install ligoDV as a matlab app and get the NDS2 client software for free. So you can easily get the 40m data from the outside world now and do the analysis on your own computer rather than login through nodus.

1)Power to the seismometers were turned down,

2)Guralp2 was moved to North side of POX table

3)Guralp2 was aligned in N-s Direction and leveled before connecting

4)Power to seismometers was turned on once Guralp2 was connected

An exercise of optimally subtracting one seismometer signal by another using weiner filters was done. Results have been summarized document attached.

I used MC_L signal from the Mode Cleaner as the desired signal with GUR2_X as witness signals. I observed good subtraction where coherence is high. But there was noise added in other frequency bands. I am not sure how to avoid that.

Please find attached documents that contains relevant plots.

Our fluorecent lights became obsolete.  We'll have change fixtures over to some more energy efficient one. Do you have any recommendation regarding to less noise performer unit?

We may go this direction of LED fluorecent lamps ?

 ~Vancuver, Canada earthquakes: magnitude 6,  5  and more shaking

Local m3.8 eq shakes PRM lose.

 After seeing all of these spikes in the BLRMS at high frequency for awhile, I power cycled the Guralp interface box (@ 10:21 PM) to see if it would randomly recenter in a different place and stop glitching.

It did - needs to be better centered (using the paddle). Plot shows how the Z channel gets better after power cycle.

How can we improve the cleanliness of the 40m IFO room 104 ? May be Mario Batali crocs if you chief chef of the lab likes it. We can do more effective things.

Atm 1 is showing the lab air quality dependence on outside air  measured at the top of the IOO chamber. This made me to measure the   differential  pressure between lab and out side.

Properly sized air conditioner is over pressurizing it's room by 0.05 [" Water] like clean assembly room.

The 40m at Vertex location is barely getting pressurized to 0.01 " W

The control room is OK with 0.04 " W but it's air quality is very bad! It is 10x worse at 0.5 micron than IFO room.

Every entry from well pressurized control room into barely pressurized  IFO  pumps dirty air to our "clean room."

This door should be closed.

The drill- room entry is ideal because it is using the same air conditioner as the  main lab, therefore it has cleaner air.

Things to do: seal holes of CES walls, seal paint wall at south end so it will shed less, replace gas kits on doors.

I have plugged the cable tray space entering the control room above Rosalba.

 Probably more important is to establish quantitatively how particle counts affects the lock acquisition or noise in the interferometer.

We don't want to adopt a "Sky is Falling" mentality as was done previously in LIGO when people were trying to outlaw burritos and perfume.

Dust monitor counts and human noses do not correlate well with the interferometer's nose.

When the vacuum system is closed, we might check to see if particle counts correlate with losses in the PMC or excess scatter on the ISC tables. If not, we should move on to other concerns.